WHILE statement

Applies to: Databricks SQL Databricks Runtime 16.3 and above

Repeat the execution of a list of statements while a condition is true.

This statement may only be used within a compound statement.

Syntax

[ label : ] WHILE cond DO
  { stmt ; } [...]
  END WHILE [ label ]

Parameters

• label

  An optional label for the loop, which is unique amongst all labels for statements within which the WHILE statement is contained. The label can be used to LEAVE or ITERATE the loop.

• cond

  Any expression evaluating to a BOOLEAN

• stmt

  A SQL statement

Examples

-- sum up all odd numbers from 1 through 10
> BEGIN
    DECLARE sum INT DEFAULT 0;
    DECLARE num INT DEFAULT 0;
    sumNumbers: WHILE num < 10 DO
      SET num = num + 1;
      IF num % 2 = 0 THEN
        ITERATE sumNumbers;
      END IF;
      SET sum = sum + num;
    END WHILE sumNumbers;
    VALUES (sum);
  END;
 25

-- Compare with the much more efficient relational computation:
> SELECT sum(num) FROM range(1, 10) AS t(num) WHERE num % 2 = 1;
 25

Related articles

• SQL Scripting
• CASE Statement
• Compound Statement
• FOR Statement
• REPEAT Statement
• IF Statement
• ITERATE Statement
• LEAVE Statement
• LOOP Statement