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+ | ====== COALESCE Function - PL/HQL Reference====== | ||
+ | COALESCE function returns first non-NULL expression. | ||
+ | |||
+ | **Syntax**: | ||
+ | |||
+ | <code language="sql"> | ||
+ | COALESCE(expr1, expr2 [, expr3, ...]); | ||
+ | </code> | ||
+ | |||
+ | **Parameters:** | ||
+ | |||
+ | | **Parameter** | **Type** | **Value** | | ||
+ | | exprN | Any | Variable or expression | | ||
+ | |||
+ | **Notes**: | ||
+ | |||
+ | * When first non-NULL expression is found the following expressions are not evaluated | ||
+ | * COALESCE and [[nvl|NVL]] functions are synonyms | ||
+ | |||
+ | **Return Value:** | ||
+ | |||
+ | * First non-NULL expression | ||
+ | * NULL if all expressions evaluate to NULL | ||
+ | |||
+ | **Return Type:** | ||
+ | |||
+ | The data type of first non-NULL expression. | ||
+ | |||
+ | **Example 1:** | ||
+ | |||
+ | <code language="sql"> | ||
+ | COALESCE(NULL, 1, 2, 3); | ||
+ | </code> | ||
+ | |||
+ | Result: 1 | ||
+ | |||
+ | **Compatibility**: Oracle, IBM DB2, Teradata, Microsoft SQL Server, PostgreSQL, MySQL and Netezza | ||
+ | |||
+ | **Version**: PL/HQL 0.03 | ||
+ | |||
+ | See also: | ||
+ | * [[nvl|NVL]] |