[数据库]MySQL: LEAVE Statement
This MySQL tutorial explains how to use the LEAVE statement in MySQL with syntax and examples.
In MySQL, the LEAVE statement is used when you want to exit a block of code identified by a label_name, such as a LOOP statement, WHILE statement, or REPEAT statement.
The syntax for the LEAVE statement in MySQL is:
Parameters or Arguments
- The name of the block of code (ie: LOOP, WHILE, REPEAT) to terminate.
- You use the LEAVE statement to terminate a block of code, such as a LOOP statement, WHILE statement, or REPEAT statement that is identified by a label_name.
Let's look at an example that shows how to use the LEAVE statement in MySQL:
DELIMITER //CREATE FUNCTION CalcIncome ( starting_value INT )RETURNS INTBEGIN DECLARE income INT; SET income = 0; label1: LOOP SET income = income + starting_value; IF income < 3000 THEN ITERATE label1; END IF; LEAVE label1; END LOOP label1; RETURN income;END; //DELIMITER ;
In this LEAVE example, we have created a loop called label1 using the LOOP statement.
The ITERATE statement would cause the loop to repeat while income is less than 3000. Once income is greater than or equal to 3000, the LEAVE statement would terminate the LOOP.