WHILE statement

Applies to: check marked yes Databricks SQL check marked yes 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
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