COALESCE (Transact-SQL)

COALESCE (Transact-SQL)

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日期:2024-09-21
COALESCE 運算式是 CASE 運算式的語法捷徑。 也就是說,查詢最佳化工具會將程式碼 COALESCE (expression1,...n) 重寫為下列 CASE 運算式: CASE WHEN (expression1 IS NOT NULL) THEN expression1 WHEN (expression2 IS NOT NULL) THEN ......看更多