Chapter 18 MySQL Shell User Guide

This section provides user documentation for MySQL Shell, an advanced client and code editor for MySQL Server. In addition to the provided SQL functionality, similar to mysql, MySQL Shell provides scripting capabilities for JavaScript and Python and includes APIs for working with MySQL. X DevAPI enables you to work with both relational and document data, see Chapter 19, Using MySQL as a Document Store. AdminAPI enables you to work with InnoDB cluster, see Chapter 20, InnoDB Cluster.

MySQL Shell enables you to prototype code using the X DevAPI to communicate with a MySQL Server running the X Plugin. The X Plugin is a new MySQL Server feature available with MySQL Server 5.7.12 and higher.

MySQL Shell is an advanced command-line client and code editor for the MySQL Server. In addition to SQL, MySQL Shell also offers scripting capabilities for JavaScript and Python. When MySQL Shell is connected to the MySQL Server through the X Protocol, the X DevAPI can be used to work with both relational and document data.

18.1 MySQL Shell Features

The following features are available in MySQL Shell.

Interactive Code Execution

MySQL Shell provides an interactive code execution mode, where you type code at the MySQL Shell prompt and each entered statement is processed, with the result of the processing printed onscreen.

Supported Languages

MySQL Shell processes code in the following languages: JavaScript, Python and SQL. Any entered code is processed as one of these languages, based on the language that is currently active. There are also specific MySQL Shell commands, prefixed with \, which enable you to configure MySQL Shell regardless of the currently selected language. For more information see Section 18.4.1, “MySQL Shell Commands”.

Batch Code Execution

In addition to the interactive execution of code, MySQL Shell can also take code from different sources and process it. This method of processing code in a non-interactive way is called Batch Execution.

As batch execution mode is intended for script processing of a single language, it is limited to having minimal non-formatted output and disabling the execution of commands. To avoid these limitations, use the --interactive command-line option, which tells MySQL Shell to execute the input as if it were an interactive session. In this mode the input is processed line by line just as if each line were typed in an interactive session. For more information see Section 18.3.5, “Batch Mode Made Interactive”.

Output Formats

MySQL Shell provides output in different formats depending on how it is used: Tabbed, Table and JSON. For more information see Section 18.3.3, “Output Formats”.

Multiple-line Support

Multiple-line code can be written using a command, enabling MySQL Shell to cache multiple lines and then execute them as a single statement. For more information see Section 18.3.5.1, “Multiple-line Support”.

Application Log

MySQL Shell can be configured to log information about the execution process. For more information see Section 18.5, “MySQL Shell Application Log”.

Supported APIs

MySQL Shell includes the following APIs implemented in JavaScript and Python which you can use to develop code that interacts with MySQL.

  • The X DevAPI enables you to work with both relational and document data when MySQL Shell is connected to a MySQL server using the X Protocol. For more information, see Chapter 19, Using MySQL as a Document Store. For documentation on the concepts and usage of X DevAPI, see X DevAPI User Guide.

  • The AdminAPI enables you to work with InnoDB cluster, which provides an integrated solution for high availability and scalability using InnoDB based MySQL databases, without requiring advanced MySQL expertise. See Chapter 20, InnoDB Cluster.

For specific documentation on the implementation of the APIs see JavaScript and Python.

X Protocol Support

MySQL Shell is designed to provide an integrated command-line client for all MySQL products which support X Protocol. The development features of MySQL Shell are designed for sessions using the X Protocol. MySQL Shell can also connect to MySQL Servers that do not support the X Protocol using the legacy MySQL Protocol. A minimal set of features from the X DevAPI are available for sessions created using the legacy MySQL protocol.

Global Session

Interaction with a MySQL Server is done through a Session object. For Python and JavaScript, a Session can be created through the getSession and getNodeSession functions of the mysqlx module. If a session is created in JavaScript mode using any of these methods, it is available only in JavaScript mode. The same happens if the session is created in Python mode. None of these sessions can be used in SQL mode.

For SQL Mode, the concept of Global Session is supported by the MySQL Shell. A Global Session is created when the connection information is passed to MySQL Shell using command-line options, or by using the \connect command.

The Global Session is used to execute statements in SQL mode and the same session is available in both Python or JavaScript modes. When a Global Session is created, a variable called session is set in the scripting languages, so you can execute code in the different languages by switching the active mode.

For more information, see Section 18.2.2, “MySQL Shell Sessions”.

18.2 Getting Started with MySQL Shell

This section describes how to get started with MySQL Shell, explaining how to connect to a MySQL server instance, and how to choose a session type.

18.2.1 MySQL Shell Connections

MySQL Shell can connect to MySQL Server using both the X Protocol and the classic MySQL protocol. The address of the MySQL Server which you want to connect to can be specified using individual parameters, such as user, hostname and port, or using a Uniform Resource Identifier (URI) type string. The following sections describe these connection methods. See Section 4.2.2, “Connecting to the MySQL Server” for more background information.

You can configure the MySQL server instance that MySQL Shell is connected to in the following ways:

These methods all support Section 18.2.1.1, “Connecting using a URI String”.

Important

Regardless of the method you choose to connect it is important to understand how passwords are handled by MySQL Shell. By default connections are assumed to require a password. The password is requested at the login prompt. To specify a password-less account use the --password option and do not specify a password, or use a : after the user in a URI type string and do not specify a password.

If you do not specify parameters for a connection the following defaults are used:

  • user defaults to the current system user name

  • host defaults to localhost

  • port defaults to the X Plugin port 33060 when using an X Protocol session, and port 3306 when using a Classic session

MySQL Shell connections using X Protocol always use TCP, using Unix sockets is not supported. MySQL Shell connections using MySQL Protocol default to using Unix sockets when the following conditions are met:

  • A TCP port is not specified

  • A host name is not specified or it is equal to localhost

  • A socket is provided with a path to a socket file

  • A classic session is specified

If a host name is specified but it is not localhost, a TCP connection is established. In this case, if a TCP port is not specified the default value of 3306 is used. If the conditions are met for a socket connection but a path to a socket file is not specified then the default socket is used. See Section 4.2.2, “Connecting to the MySQL Server”.

18.2.1.1 Connecting using a URI String

You can configure the MySQL Server which MySQL Shell connects to by passing the connection data in URI type string format. Such strings can be used with the --uri command option, the MySQL Shell \connect command, and the shell.connect() method.

The URI type string should use the following format:

scheme://[user[:[password]]@]target[:port][/schema][?attribute1=value1&attribute2=value2...
Important

Percent encoding must be used for reserved characters in the elements of the URI type string. For example, if you specify a password that includes the @ character, the character must be replaced by %40.

The elements of a URI type string for a MySQL Shell connection are:

  • scheme: this element is required and specifies the connection protocol to use, currently either mysql for classic connection protocol and mysqlx for X Protocol.

  • user: this element is optional and specifies the MySQL user account to be used for the authentication process.

  • password: this element is optional and specifies the password to be used for the authentication process.

    Warning

    Storing the password in the URI type string is insecure and not recommended.

  • target: this element is required and specifies the server instance the connection refers to. Can be either TCP connection information, a Unix socket path or a Windows named-pipe. If not specified, localhost is used by default.

    • TCP connection information can be either a host name, an IPv4 address, or an IPv6 address. Can include an optional port number in the format host:port, where port specifies a network port which the target MySQL server is listening on for connections. If not specified, 33060 is used by default for X Protocol connections, and 3306 is the default for classic MySQL protocol connections.

    • Unix socket and Windows named-pipe values are local file paths. There are two ways to specify such paths, using percent encoding or surrounding the path with parentheses, removing the need to percent encode characters such as the common directory separator /. For example, to connect as root@localhost using the Unix socket /tmp/mysqld.sock either specify the path using parenthesis as root@localhost?socket=(/tmp/mysqld.sock) or using percent encoding as root@localhost?socket=%2Ftmp%2Fmysqld.sock%2F.

  • schema: this element is optional and specifies the database to be set as default when the connection is established.

  • ?attribute=value: this element is optional and specifies a data dictionary that contains options.

If no password is specified using the URI type string, which is recommended, then the password is prompted for. The following examples show how to specify URI type strings with the user name user, in each case the password is prompted for:

  • An X Protocol connection to a local server instance listening at port 33065.

    mysqlx://user@localhost:33065
    
  • A classic MySQL protocol X Protocol connection to a local server instance listening at port 3333.

    mysql://user@localhost:3333
    
  • An X Protocol connection to a remote server instance, using a host name, an IPv4 address and an IPv6 address.

    mysqlx://user@server.example.com/
    mysqlx://user@198.51.100.14:123
    mysqlx://user@[2001:db8:85a3:8d3:1319:8a2e:370:7348]
    		
  • An optional path can be specified, which represents a database schema.

    mysqlx://user@198.51.100.1/world%5Fx
    mysqlx://user@198.51.100.2:33060/world
    		
  • An optional query can be specified, consisting of values in the form of a key=value pair or as a single key. The , character is used as a separator for values, a combination of multiple pairs and keys can be specified. Values can be of type list, list values are ordered by appearance. Strings must be percent encoded.

    ssluser@127.0.0.1?ssl-ca%3D%2Froot%2Fclientcert%2Fca-cert.pem%26ssl-cert%3D%2Fro\
    ot%2Fclientcert%2Fclient-cert.pem%26ssl-key%3D%2Froot%2Fclientcert%2Fclient-key
    .pem
    

Although using a password-less account is insecure and not recommended, you can specify a user without a password using a : after the user name, for example:

mysqlx://user:@localhost

18.2.1.2 Connecting using Individual Parameters

In addition to specifying connection parameters using a URI type string, it is also possible to define the connection data when starting MySQL Shell using separate command parameters for each value. For a full reference of MySQL Shell command options see Section 4.5.7, “mysqlsh — The MySQL Shell”.

Use the following connection related parameters:

The first 5 parameters match the elements used in the URI type string format described at Section 18.2.1.1, “Connecting using a URI String”.

The --password parameter indicates the user should connect without a password.

For consistency, the following aliases are supported for some parameters:

When parameters are specified in multiple ways, for example using both the --uri option and specifying individual parameters such as --user, the following rules apply:

  • If an argument is specified more than once the value of the last appearance is used.

  • If both individual connection arguments and --uri are specified, the value of --uri is taken as the base and the values of the individual arguments override the specific component from the base URI.

    For example to override user from the URI:

    shell> mysqlsh --uri user@localhost:33065 --user otheruser
    

The following examples show how to use command parameters to specify connections. Attempt to establish an X Protocol connection with a specified user at port 33065.

shell> mysqlsh --mysqxl -u user -h localhost -P 33065

Attempt to establish a classic MySQL protocol connection with a specified user.

shell> mysqlsh --mysql -u user -h localhost

18.2.1.3 Using Encrypted Connections

Using encrypted connections is possible when connecting to a TLS (sometimes referred to as SSL) enabled MySQL server. Much of the configuration of MySQL Shell is based on the options used by MySQL server, see Section 6.4, “Using Encrypted Connections” for more information.

To configure an encrypted connection at startup of MySQL Shell, use the following command options:

  • --ssl : Deprecated, to be removed in a future version. This option enables or disables encrypted connections.

  • --ssl-mode : This option specifies the security state of the connection to the server.

  • --ssl-ca=filename: The path to a file in PEM format that contains a list of trusted SSL Certificate Authorities.

  • --ssl-capath=directory: The path to a directory that contains trusted SSL Certificate Authority certificates in PEM format.

  • --ssl-cert=filename: The name of the SSL certificate file in PEM format to use for establishing an encrypted connection.

  • --ssl-cipher=name: The name of the SSL cipher to use for establishing an encrypted connection.

  • --ssl-key=filename: The name of the SSL key file in PEM format to use for establishing an encrypted connection.

  • --ssl-crl=name: The path to a file containing certificate revocation lists in PEM format.

  • --ssl-crlpath=directory: The path to a directory that contains files containing certificate revocation lists in PEM format.

  • --tls-version=version: The TLS protocols permitted for encrypted connections.

Alternatively the SSL options can be encoded as part of a URI type string as part of the query element. The available SSL options are the same as those listed above, but written without the proceeding hyphens. For example ssl-ca is the equivalent of --ssl-ca.

Paths specified in a URI type string must be percent encoded, for example:

ssluser@127.0.0.1?ssl-ca%3D%2Froot%2Fclientcert%2Fca-cert.pem%26ssl-cert%3D%2Fro\
ot%2Fclientcert%2Fclient-cert.pem%26ssl-key%3D%2Froot%2Fclientcert%2Fclient-key
.pem

See Section 18.2.1.1, “Connecting using a URI String” for more information.

18.2.1.4 Connections in JavaScript and Python

When a connection is made using the command options or by using any of the MySQL Shell commands, a global session object is created. This session is global because once created, it can be used in any of the MySQL Shell execution modes.

Any global session object is available in JavaScript or Python modes because a variable called session holds a reference to it.

In addition to the global session object, sessions can be established and assigned to a different variable by using the functions available in the mysql and mysqlx JavaScript and Python modules.

For example, the following functions are provided by these modules:

  • mysqlx.getSession(connectionData[, password])

    The returned object can be Session if the object was created or retrieved using a Session instance, and ClassicSession if the object was created or retrieved using a ClassicSession instance.

  • mysql.getClassicSession(connectionData[, password])

    The returned object is a ClassicSession which uses the traditional MySQL protocol and has a limited development API.

connectionData can be either a URI type string as specified at Section 18.2.1.1, “Connecting using a URI String” or a dictionary containing the connection parameters.

The following example shows how to create a Session using the X Protocol:

mysql-js> var mysession1=mysqlx.getSession('root@localhost:33060', 'password');
mysql-js> session
<Session:root@localhost>
mysql-js>

The following example shows how to create a ClassicSession:

mysql-js> var mysession2=mysql.getClassicSession('root@localhost:3306', 'password');
mysql-js> session
<ClassicSession:root@localhost:3306>
mysql-js>
18.2.1.4.1 Using Encrypted Connections in Code

To establish an encrypted connection, set the SSL information in the connectionData dictionary. For example:

mysql-js> var session=mysqlx.getSession({host: 'localhost',
                                             dbUser: 'root',
                                             dbPassword: 'password',
                                             ssl_ca: "path_to_ca_file",
                                             ssl_cert: "path_to_cert_file",
                                             ssl_key: "path_to_key_file"});

18.2.2 MySQL Shell Sessions

This section explains the different types of sessions in MySQL Shell and how to create and configure them.

18.2.2.1 MySQL Shell Sessions Explained

MySQL Shell is a unified interface to operate MySQL Server through scripting languages such as JavaScript or Python. To maintain compatibility with previous versions, SQL can also be executed in certain modes. A connection to a MySQL server is required. In MySQL Shell these connections are handled by a Session object.

The following types of Session object are available:

  • NodeSession: Use this session type for new application development to communicate with MySQL server instances which have the X Protocol enabled. It offers the best integration with MySQL Server, and therefore, it is used by default.

  • ClassicSession Use this session type to interact with MySQL Servers that do not have the X Protocol enabled. The development API available for this type of session is very limited. For example, there are no CRUD operations, no collection handling, and binding is not supported.

Choosing a MySQL Shell Session Type

MySQL Shell creates a Session object by default. You can either configure the session type using MySQL Shell command options, the scheme element of a URI type string, or provide an option to the \connect command. To choose which type of session should be created when starting MySQL Shell, use one of these options:

  • --sqln creates a Node session, connected using X Protocol.

  • --sqlc creates a ClassicSession, connected using MySQL protocol.

To choose which type of session to use when defining a URI type string use one of these options:

  • Specify mysqlx to create an X Protocol session. The X Plugin must be installed on the server instance, see Chapter 19, Using MySQL as a Document Store for more information.

  • Specify mysql to create a classic MySQL protocol session.

For more information, see Section 18.2.1.1, “Connecting using a URI String”.

Creating a Session Using Shell Commands

If you open MySQL Shell without specifying connection parameters, MySQL Shell opens without an established global session. It is possible to establish a global session once MySQL Shell has been started using the MySQL Shell \connect URI command, where URI is a URI type string as defined at Section 18.2.1.1, “Connecting using a URI String”. For example:

  • \connect URI: Creates a Node session. Attempts to use X Protocol by default, and falls back to MySQL protocol.

  • \connect -n URI: Creates a Node session.

  • \connect -c URI: Creates a ClassicSession using MySQL protocol.

For example:

	mysql-js> \connect mysqlx://user@localhost:33060

Alternatively, use the shell.connect('URI' method. For example this is equivalent to the above \connect> command:

mysql-js> shell.connect('mysqlx://user@localhost:33060')

18.2.3 MySQL Shell Global Variables

MySQL Shell reserves certain variables as global variables, which are assigned to commonly used objects in scripting. This section describes the available global variables and provides examples of working with them. The global variables are:

  • session represents the global session if one has been established.

  • db represents a schema if one has been defined, for example by a URI type string.

  • dba represents the AdminAPI, a component of InnoDB cluster which enables you to administer clusters of server instances. See Chapter 20, InnoDB Cluster.

  • shell provides general purpose functions, for example to configure MySQL Shell.

Important

These words are reserved and cannot be used, for example as names of variables.

By using these global objects, MySQL Shell provides interactive error resolution for common situations. For example:

  • Attempting to use an undefined session global variable.

  • Attempting to retrieve an nonexistent schema using session.

  • Attempting to use an undefined db global variable.

Undefined Global Session

The global session variable is set when a global session is established. When a global session is established, issuing a session statement in MySQL Shell displays the session type and its URI as follows:

mysql-js> session
<NodeSession:root@localhost:33060>
mysql-js>

If no global session has been established, MySQL Shell displays the following:

mysql-js> session
<Undefined>
mysql-js>

If you attempt to use the session variable when no global session is established, interactive error resolution starts and you are prompted to provide the required information to establish a global session. If the session is successfully established, it is assigned to the session variable. The prompts are:

  • An initial prompt explains that no global session is established and asks if one should be established.

  • If you choose to set a global session, the session type is requested.

  • The URI type string to connect to the server instance is requested. See Section 18.2.1.1, “Connecting using a URI String”.

  • If required, a password is requested.

For example:

mysql-js> session.uri
The global session is not set, do you want to establish a session?

   1) MySQL Document Store Session through X Protocol
   2) Classic MySQL Session

Please select the session type or ENTER to cancel: 2
Please specify the MySQL server URI: root@localhost
Enter password: 
root@localhost:
mysql-js> session
<ClassicSession:root@localhost:>

Undefined db Variable

The global db variable is set when a global session is established and a default schema is configured. For example, using a URI type string such as root@localhost/sakila to establish a global session connected to the MySQL Server at localhost, on port 33060, as the user root, assigns the schema sakila to the global variable db. Once a schema is defined, issuing db at the MySQL Shell prompt prints the schema name as follows:

mysql-js> db
<Schema:world_x>
mysql-js>

If there is no global session established, the following is displayed:

mysql-js> db
<Undefined>
mysql-js>

If you attempt to use the db variable when no global session has been established, the following error is displayed:

mysql-js> db.getCollections()
LogicError: The db variable is not set, establish a global session first.
at (shell):1:2
in db.getCollections()
^

If a global session has been established but you attempt to use an undefined db, interactive error resolution begins and you are prompted to define an active schema by providing the schema name. If this succeeds the db variable is set to the defined schema. For example:

mysql-js> db.getCollections()
The db variable is not set, do you want to set the active schema? [y/N]:y
Please specify the schema:world_x
[
<Collection:countryinfo>
]
mysql-js> db
<Schema:world_x>
mysql-js>

Retrieving an Nonexistent Schema

If you attempt to use session to retrieve an nonexistent schema, interactive error resolution provides the option to create the schema.

mysql-js> var mySchema = session.getSchema('my_test')
The schema my_test does not exist, do you want to create it? [y/N]: y

mysql-js> mySchema
<Schema:my_test>
mysql-js>

In all cases, if you do not provide the information required to resolve each situation, a proper result of executing the requested statement on an undefined variable is displayed.

18.3 MySQL Shell Code Execution

This section explains how code execution works in MySQL Shell.

18.3.1 Interactive Code Execution

The default mode of MySQL Shell provides interactive execution of database operations that you type at the command prompt. These operations can be written in JavaScript, Python or SQL depending on the curent Section 18.3.4, “Active Language”. When executed, the results of the operation are displayed on-screen.

As with any other language interpreter, MySQL Shell is very strict regarding syntax. For example, the following JavaScript snippet reads and prints the documents in a collection:

var mysqlx = require('mysqlx').mysqlx;
var mySession = mysqlx.getSession('user:pwd@localhost');
var result = mySession.world_x.countryinfo.find().execute();
var record = result.fetchOne();
while(record){
  print(record);
  record = result.fetchOne();
}

As seen above, the call to find() is followed by the execute() function. CRUD database commands are only actually executed on the MySQL Server when execute() is called. However, when working with MySQL Shell interactively, execute() is implicitly called whenever you press Return on a statement. Then the results of the operation are fetched and displayed on-screen. The rules for when you need to call execute() or not are as follows:

  • When using MySQL Shell in this way, calling execute() becomes optional on:

    • Collection.add()

    • Collection.find()

    • Collection.remove()

    • Collection.modify()

    • Table.insert()

    • Table.select()

    • Table.delete()

    • Table.update()

    • NodeSession.sql()

  • Automatic execution is disabled if the object is assigned to a variable. In such a case calling execute() is mandatory to perform the operation.

  • When a line is processed and the function returns any of the available Result objects, the information contained in the Result object is automatically displayed on screen. The functions that return a Result object include:

    • The SQL execution and CRUD operations (listed above)

    • Transaction handling and drop functions of the session objects in both mysql and mysqlx modules: -

      • startTransaction()

      • commit()

      • rollback()

      • dropSchema()

      • dropTable()

      • dropCollection()

      • dropView()

      • ClassicSession.runSql()

Based on the above rules, the statements needed in the MySQL Shell in interactive mode to establish a session, query, and print the documents in a collection are:

mysql-js> var mysqlx = require('mysqlx').mysqlx;
mysql-js> var mySession = mysqlx.getSession('user:pwd@localhost');

No call to execute() is needed and the Result object is automatically printed.

mysql-js> mySession.world_x.countryinfo.find();

Formatting Results Vertically

When executing SQL using MySQL Shell you can display results in a column-per-row format with the \G command, in a similar way to mysql. If a statement is terminated with \G instead of the active delimiter (which defaults to ;), it is executed by the server and the results are displayed in vertical format, regardless of the current default output format. For example issuing a statement such as

SELECT * FROM mysql.user \G

displays the results vertically.

Multiple SQL statements on the same line which are separated by \G are executed separately as if they appeared one per line., for example

select 1\Gselect 2\Gselect 3\G

In other words \G functions as a normal delimiter.

18.3.2 Batch Code Execution

As well as interactive code execution, MySQL Shell provides batch code execution from:

  • A file loaded for processing.

  • A file containing code that is redirected to the standard input for execution.

  • Code from a different source that is redirected to the standard input for execution.

The input is processed based on the current programming language selected in MySQL Shell, which defaults to JavaScript. For example:

Loading JavaScript code from a file for batch processing.

shell> mysqlsh --file code.js

Redirecting a JavaScript file to standard input for execution.

shell> mysqlsh < code.js

Redirecting SQL to standard input for execution.

shell> echo "show databases;" | mysqlsh --sql --uri root@198.51.100.141:33060

Executable Scripts

Starting with version 1.0.4, on Linux you can create executable scripts that run with MySQL Shell by including a #! line as the first line of the script. This line should provide the full path to MySQL Shell and include the --file option. For example:

#!/usr/local/mysql-shell/bin/mysqlsh --file
print("Hello World\n");

The script file must be marked as executable in the filesystem. Running the script invokes MySQL Shell and it executes the contents of the script.

18.3.3 Output Formats

The output of the commands processed on the server can be formatted in different ways. This section details the different available output formats.

18.3.3.1 Table Format

The table format is used by default when MySQL Shell is in interactive mode. The output is presented as a formatted table for a better view and to aid analysis.

mysql-sql> select * from sakila.actor limit 3;
+----------+-------------+----------------+----------------------+
| actor_id | first_name  | last_name      | last_update          |
+----------+-------------+----------------+----------------------+
|        1 | PENELOPE    | GUINESS        | 2006-02-15 4:34:33   |
|        2 | NICK        | WAHLBERG       | 2006-02-15 4:34:33   |
|        3 | ED          | CHASE          | 2006-02-15 4:34:33   |
+----------+-------------+----------------+----------------------+
3 rows in set (0.00 sec)

mysql-sql>

To get this output format when running in batch mode, use the --table command-line option.

18.3.3.2 Tab Separated Format

This format is used by default when running MySQL Shell in batch mode, to have better output for automated analysis.

>echo "select * from sakila.actor limit 3;" | mysqlsh --classic --uri root@198.51.100.141:33460
actor_id        first_name      last_name       last_update
1       PENELOPE        GUINESS 2006-02-15 4:34:33
2       NICK    WAHLBERG        2006-02-15 4:34:33
3       ED      CHASE   2006-02-15 4:34:33

18.3.3.3 JSON Format Output

MySQL Shell supports the JSON format for output and it is available both in interactive and batch mode. This output format can be enabled using the --json command-line option:

JSON Format in Batch Mode

shell>echo "select * from sakila.actor limit 3;" | mysqlsh --json --sqlc --uri root@198.51.100.141:3306
{"duration":"0.00 sec","info":"","row_count":3,"rows":[[1,"PENELOPE","GUINESS",{"year":2006,"month":1,"day":15,"hour":4,"minute":34,"second":33.0}],[2,"NICK","WAHLBERG",{"year":2006,"month":1,"day":15,"hour":4,"minute":34,"second":33.0}],[3,"ED","CHASE",{"year":2006,"month":1,"day":15,"hour":4,"minute":34,"second":33.0}]],"warning_count":0}

shell>echo "select * from sakila.actor limit 3;" | mysqlsh --json=raw --sqlc --uri root@198.51.100.141:3306
{"duration":"0.00 sec","info":"","row_count":3,"rows":[[1,"PENELOPE","GUINESS",{"year":2006,"month":1,"day":15,"hour":4,"minute":34,"second":33.0}],[2,"NICK","WAHLBERG",{"year":2006,"month":1,"day":15,"hour":4,"minute":34,"second":33.0}],[3,"ED","CHASE",{"year":2006,"month":1,"day":15,"hour":4,"minute":34,"second":33.0}]],"warning_count":0}

shell>echo "select * from sakila.actor limit 3;" | mysqlsh --json=pretty --sqlc --uri root@198.51.100.141:3306
{
    "duration": "0.00 sec",
    "info": "",
    "row_count": 3,
    "rows": [
        [
            1,
            "PENELOPE",
            "GUINESS",
            {
                "year": 2006,
                "month": 1,
                "day": 15,
                "hour": 4,
                "minute": 34,
                "second": 33.0
            }
        ],
        [
            2,
            "NICK",
            "WAHLBERG",
            {
                "year": 2006,
                "month": 1,
                "day": 15,
                "hour": 4,
                "minute": 34,
                "second": 33.0
            }
        ],
        [
            3,
            "ED",
            "CHASE",
            {
                "year": 2006,
                "month": 1,
                "day": 15,
                "hour": 4,
                "minute": 34,
                "second": 33.0
            }
        ]
    ],
    "warning_count": 0
}
shell>

JSON Format in Interactive Mode (started with --json=raw)

mysql-sql> select * from sakila.actor limit 3;
{"duration":"0.00 sec","info":"","row_count":3,"rows":[[1,"PENELOPE","GUINESS",{"year":2006,"month":1,"day":15,"hour":4,"minute":34,"second":33.0}],[2,"NICK","WAHLBERG",{"year":2006,"month":1,"day":15,"hour":4,"minute":34,"second":33.0}],[3,"ED","CHASE",{"year":2006,"month":1,"day":15,"hour":4,"minute":34,"second":33.0}]],"warning_count":0}

mysql-sql>

JSON Format in Interactive Mode (started with --json=pretty)

mysql-sql> select * from sakila.actor limit 3;
{
    "duration": "0.00 sec",
    "info": "",
    "row_count": 3,
    "rows": [
        [
            1,
            "PENELOPE",
            "GUINESS",
            {
                "year": 2006,
                "month": 1,
                "day": 15,
                "hour": 4,
                "minute": 34,
                "second": 33.0
            }
        ],
        [
            2,
            "NICK",
            "WAHLBERG",
            {
                "year": 2006,
                "month": 1,
                "day": 15,
                "hour": 4,
                "minute": 34,
                "second": 33.0
            }
        ],
        [
            3,
            "ED",
            "CHASE",
            {
                "year": 2006,
                "month": 1,
                "day": 15,
                "hour": 4,
                "minute": 34,
                "second": 33.0
            }
        ]
    ],
    "warning_count": 0
}

mysql-sql>

18.3.3.4 Result Metadata

When an operation is executed, in addition to any results returned, some additional information is available. This includes information such as the number of affected rows, warnings, duration, and so on, when any of these conditions is true:

  • JSON format is being used for the output

  • MySQL Shell is running in interactive mode.

18.3.4 Active Language

MySQL Shell can execute SQL, JavaScript or Python code, but only one language can be active at a time. The active mode determines how the executed statements are processed:

  • If using SQL mode, statements are processed as SQL which means they are sent to the MySQL server for execution.

  • If using JavaScript mode, statements are processed as JavaScript code.

  • If using Python mode, statements are processed as Python code.

When running MySQL Shell in interactive mode, activate a specific language by entering the commands: \sql, \js, \py.

When running MySQL Shell in batch mode, activate a specific language by passing any of these command-line options: --js, --py or --sql. The default mode if none is specified is JavaScript.

Use MySQL Shell to execute the content of the file code.sql as SQL.

shell> mysqlsh --sql < code.sql

Use MySQL Shell to execute the content of the file code.js as JavaScript code.

shell> mysqlsh < code.js

Use MySQL Shell to execute the content of the file code.py as Python code.

shell> mysqlsh --py < code.py

18.3.5 Batch Mode Made Interactive

This section describes code execution in batch mode.

  • In batch mode, all the command logic described above is not available, only valid code for the active language can be executed.

  • When processing SQL code, it is executed statement by statement using the following logic: read/process/print result.

  • When processing non-SQL code, it is loaded entirely from the input source and executed as a unit.

Use the --interactive (or -i) command-line option to configure MySQL Shell to process the input source as if it were being issued in interactive mode; this enables all the features provided by the Interactive mode to be used in batch processing.

Note

In this case, whatever the source is, it is read line by line and processed using the interactive pipeline.

18.3.5.1 Multiple-line Support

It is possible to specify statements over multiple lines. When in Python or JavaScript mode, multiple-line mode is automatically enabled when a block of statements starts like in function definitions, if/then statements, for loops, and so on. In SQL mode multiple line mode starts when the command \ is issued.

Once multiple-line mode is started, the subsequently entered statements are cached.

For example:

mysql-sql> \
... create procedure get_actors()
... begin
...   select first_name from sakila.actor;
... end
...
mysql-sql>

18.4 Configuring MySQL Shell

This section explains how to configure MySQL Shell using commands executable from the interactive code editor and command options. For a description of MySQL Shell command options, see Section 4.5.7, “mysqlsh — The MySQL Shell”.

18.4.1 MySQL Shell Commands

MySQL Shell provides commands which enable you to modify the execution environment of the code editor, for example to configure the active programming language or a MySQL Server connection. The following table lists the commands that are available regardless of the currently selected language. As commands need to be available independent of the execution mode, they start with an escape sequence, the \ character.

CommandAlias/ShortcutDescription

\help

\h or \?

Prints help about MySQL Shell commands.

\quit

\q or \exit

Exit MySQL Shell.

\

 

In SQL mode, begin multiple-line mode. Code is cached and executed when an empty line is entered.

\status

\s

Show the current MySQL Shell status.

\js

 

Switch execution mode to JavaScript.

\py

 

Switch execution mode to Python.

\sql

 

Switch execution mode to SQL.

\connect

\c

Connect to a MySQL Server with a URI using an Node session (X Protocol).

\connect_node

\cn

(Removed in version 1.0.4, use \connect -n) Connect to a MySQL Server with a URI using a Node session.

\connect_classic

\cc

(Removed in version 1.0.4, use \connect -c) Connect to a MySQL Server with a URI using a Classic session (MySQL Protocol).

\use

 

Specify the schema to use.

\source

\.

Execute a script file using the active language.

\warnings

\W

Show any warnings generated by a statement.

\nowarnings

\w

Do not show any warnings generated by a statement.

\lsconn

\lsc

Print the connection data for the stored sessions.

\saveconn

\savec

Save connection data of a session, optionaly use -f to force overwriting an existing connection.

\addconn

\addc

(Removed in version 1.0.4, see \saveconn) Store the connection data of a session.

\rmconn

 

Removes a stored session.

\chconn

 

(Removed in version 1.0.4, see \saveconn) Updates a stored session.

Help Command

The \help command can be used with or without parameters. When used without parameters a general help is printed including information about:

  • Available commands.

  • Available commands for the active mode.

When used with a parameter, the parameter must be a valid command. If that is the case, help for that specific command is printed including:

  • Description

  • Supported aliases if any

  • Additional help if any

For example:

\help connect

If the parameter is not a valid command, the general help is printed.

Connect Command

The \connect command is used to connect to a MySQL Server using an URI type string. See Section 18.2.1.1, “Connecting using a URI String”.

For example:

\connect root@localhost:3306

If a password is required you are prompted for it.

Use the -n option to create a Node session, using the X Protocol to connect to a single server. For example:

\connect -n root@localhost:3306

Use the -c option to create a Classic session, enabling you to use the MySQL Protocol to issue SQL commands directly on a server. For example:

\connect -c root@localhost:3306

Status Command

The \status command displays information about the current global connection. This includes information about the server connected to, the character set in use, uptime, and so on.

Source Command

The \source command is used to execute code from a script at a given path. For example:

\source /tmp/mydata.sql

You can execute either SQL, JavaScript or Python code. The code in the file is executed using the active language, so to process SQL code the MySQL Shell must be in SQL mode.

Warning

As the code is executed using the active language, executing a script in a different language than the currently selected execution mode language could lead to unexpected results.

Use Command

The \use command enables you to choose which schema is active, for example:

\use schema_name

The \use command requires a global development session to be active. The \use command sets the current schema to the specified schema_name and updates the db variable to the object that represents the selected schema.

18.5 MySQL Shell Application Log

This section explains the logging provided by MySQL Shell, where to find logs and how to configure the level of logging.

MySQL Shell can be configured to generate an application log file with information about issues of varying severity. You can use this information to verify the state of MySQL Shell while it is running. The log format is plain text and entries contain a timestamp and description of the problem. For example:

2016-04-05 22:23:01: Error: Default Domain: (shell):1:8: MySQLError: You have an error
in your SQL syntax; check the manual that corresponds to your MySQL server version for
the right syntax to use near '' at line 1 (1064) in session.sql("select * from t
limit").execute().all();

The amount of information to add to the log can be configured using --log-level. See Configuring Logging.

MySQL Shell Log File Location

The location of the log file is the user configuration path and the file is named mysqlsh.log.

Log File on Windows

On Windows, the default path to the log file is %APPDATA%\MySQL\mysqlsh\mysqlsh.log

To find the location of %APPDATA% on your system, echo it from the comand-line. For example:

C:>echo %APPDATA%
C:\Users\exampleuser\AppData\Roaming

On Windows, the path is determined by the result of gathering the %APPDATA% folder specific to that user, and then appending MySQL\mysqlsh. Using the above example results in C:\Users\exampleuser\AppData\Roaming\MySQL\mysqlsh\mysqlsh.log.

Log File on Unix-based Systems

For a machine running Unix, the default path is ~/.mysqlsh/mysqlsh.log where ~ represents your home directory. The environment variable HOME also represents the home directory. Appending .mysqlsh to the this home directory determines the default path to the logs. For example:

shell>echo $HOME
/home/exampleuser

Therefore the location of the MySQL Shell file on this system is /home/exampleuser/.mysqlsh/mysqlsh.log.

These paths can be overridden on all platforms by defining the environment variable MYSQL_USER_CONFIG_PATH. The value of this variable replaces %APPDATA% in Windows or $HOME in Unix.

Configuring Logging

By default, logging is disabled in MySQL Shell. To enable logging use the --log-level command option when starting MySQL Shell. The value assigned to --log-level controls the level of detail in the log. The level of logging can be defined using either numeric levels from 1 to 8, or equivalent named levels as shown in the following table.

Log Level NumberLog Level NameMeaning

1

none

No logging, the default

2

internal

Internal Error

3

error

Errors are logged

4

warning

Warnings are logged

5

info

Information is logged

6

debug

Debug information is logged

7

debug2

Debug with more information is logged

8

debug3

Debug with full information is logged

The numeric and named levels are equivalent. For example there is no difference in logging when starting MySQL Shell in either of these ways:

shell>mysqlsh --log-level=4
shell>mysqlsh --log-level=warning

18.6 Customizing MySQL Shell

MySQL Shell offers the ability to customize the behavior and code execution environment through startup scripts, which are executed when the application is first run. Using such scripts enables you to:

  • Add additional search paths for Python or JavaScript modules.

  • Override the default prompt used by the Python and JavaScript modes.

  • Define global functions or variables.

  • Any other possible initialization through JavaScript or Python.

18.6.1 Working With Start-Up Scripts

When MySQL Shell enters either into JavaScript or Python mode, it searches for startup scripts to be executed. The startup scripts are JavaScript or Python specific scripts containing the instructions to be executed when the corresponding mode is initialized.

Startup scripts must be named as follows:

  • For JavaScript mode: mysqlshrc.js

  • For Python mode: mysqlshrc.py

MySQL Shell searches the following paths for these files (in order of execution).

On Windows:

  1. %PROGRAMDATA%MySQLmysqlshmysqlshrc.[js|py]

  2. %MYSQLSH_HOME%sharedmysqlshmysqlshrc.[js|py]

  3. <mysqlsh binary path>mysqlshrc.[js|py]

  4. %APPDATA%MySQLmysqlshmysqlshrc.[js|py]

On Linux and OSX:

  1. /etc/mysql/mysqlsh/mysqlshrc.[js|py]

  2. $MYSQLSH_HOME/shared/mysqlsh/mysqlshrc.[js|py]

  3. <mysqlsh binary path>/mysqlshrc.[js|py]

  4. $HOME/.mysqlsh/mysqlshrc.[js|py]

The environment variable MYSQLSH_HOME defines the root folder of a standard setup of MySQL Shell. If MYSQLSH_HOME is not defined it is automatically calculated based on the location of the MySQL Shell binary, therefore on many standard setups it is not required to define MYSQLSH_HOME.

If MYSQLSH_HOME is not defined and the MySQL Shell binary is not in a standard install folder structure, then the path defined in option 3 in the above lists is used. If using a standard install or if MYSQLSH_HOME points to a standard install folder structure, then the path defined in option 3 is not used.

Warning

The lists above also define the order of searching the paths, so if something is defined in two different scripts, the script executed later takes precedence.

18.6.2 Adding Module Search Paths

There are two ways to add additional module search paths:

  • Through environment variables

  • Through startup scripts

18.6.2.1 Environment Variables

Python uses the PYTHONPATH environment variable to allow extending the search paths for python modules. The value of this variable is a list of paths separated by:

  • A colon character in Linux and OSX

  • A semicolon character in Windows

To achieve this in JavaScript, MySQL Shell supports defining additional JavaScript module paths using the MYSQLSH_JS_MODULE_PATH environment variable. The value of this variable is a list of semicolon separated paths.

18.6.2.2 Startup Scripts

The addition of module search paths can be achieved for both languages through the corresponding startup script.

For Python modify the mysqlshrc.py file and append the required paths into the sys.path array.

# Import the sys module
import sys

# Append the additional module paths
sys.path.append('~/custom/python')
sys.path.append('~/other/custom/modules')

For JavaScript the same task is achieved by adding code into the mysqlshrc.js file to append the required paths into the predefined shell.js_module_paths array.

// Append the additional module paths
shell.js.module_paths[shell.js.module_paths.length] = '~/custom/js';
shell.js.module_paths[shell.js.module_paths.length] = '~/other/custom/modules';

18.6.3 Overriding the Default Prompt

MySQL Shell uses a default prompt for both Python ( mysql-py> ) and JavaScript ( mysql-js> ).

You can customize the language specific prompt using the shell.custom_prompt() function. This function must return a string that is used as the prompt. To have a custom prompt when MySQL Shell starts, define this function in a startup script. The following example shows how this functionality can be used.

In Python shell.custom_prompt() could be defined as:

# Import the sys module
from time import gmtime, strftime

def my_prompt():
  ret_val = strftime("%H:%M:%S", gmtime())

  if session and session.isOpen():
    data = shell.parseUri(session.getUri())

    ret_val = "%s-%s-%s-py> " % (ret_val, data.dbUser, data.host)
  else:
    ret_val = "%s-disconnected-py> " % ret_val

  return ret_val


shell.custom_prompt = my_prompt

In JavaScript shell.custom_prompt() could be defined as:

shell.custom_prompt = function(){
  var now = new Date();

  var ret_val = now.getHours().toString()+ ":" + now.getMinutes().toString() + ":" + now.getSeconds().toString();

  if (session && session.isOpen()){
    var data = shell.parseUri(session.getUri());

    ret_val += "-" + data.dbUser + "-" + data.host + "-js> ";
  }
  else
    ret_val += "-disconnected-js> ";

  return ret_val;
}

The following example demonstrates using the custom prompt functions defined above in startup script. The prompts show the current system time, and if a session is open the current user and host:

Welcome to MySQL Shell 1.0.4 Development Preview

Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type '\help', '\h' or '\?' for help.

Currently in JavaScript mode. Use \sql to switch to SQL mode and execute queries.
14:34:32-disconnected-js> \py
Switching to Python mode...

19:34:39-disconnected-py> \connect root:@localhost
Creating an X Session to root@localhost:33060
No default schema selected.

19:34:50-root-localhost-py> \js
Switching to JavaScript mode...
14:34:57-root-localhost-js>