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.

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 commands that are treated as “shell commands” which enable you to configure MySQL Shell or retrieve information. For more information see Section 18.4.1, “MySQL Shell Commands”.

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”.

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 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”.

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

Code written in MySQL Shell uses the X DevAPI, provided for Python and JavaScript. For general information, see X DevAPI User Guide. For specific documentation on the implementation of the API see JavaScript and Python.

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.

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 18.2.1, “MySQL Shell Sessions”.