15.6.1 BEGIN ... END Compound Statement (original) (raw)

15.6.1 BEGIN ... END Compound Statement

[begin_label:] BEGIN
    [statement_list]
END [end_label]

BEGIN ... END syntax is used for writing compound statements, which can appear within stored programs (stored procedures and functions, triggers, and events). A compound statement can contain multiple statements, enclosed by the BEGIN andEND keywords.statementlist represents a list of one or more statements, each terminated by a semicolon (;) statement delimiter. The_statementlist_ itself is optional, so the empty compound statement (BEGIN END) is legal.

BEGIN ... END blocks can be nested.

Use of multiple statements requires that a client is able to send statement strings containing the ; statement delimiter. In the mysql command-line client, this is handled with the delimiter command. Changing the ; end-of-statement delimiter (for example, to //) permit ; to be used in a program body. For an example, seeSection 27.1, “Defining Stored Programs”.

A BEGIN ... END block can be labeled. SeeSection 15.6.2, “Statement Labels”.

The optional [NOT] ATOMIC clause is not supported. This means that no transactional savepoint is set at the start of the instruction block and theBEGIN clause used in this context has no effect on the current transaction.