The COALESCE() function returns the first non-null value in a list. Syntax COALESCE(val1,val2,...,val_n) Parameter Values ParameterDescription val1, val2, val_nRequired. The values to test Technical Details Works in:SQL Server (starting with 2008), Azure SQL Database, Azure SQL Data...
2. 方法必须是静态的并且要有SqlFunction特性,表值函数的返回值是IEnurable 第二步:注册程序集到sql server中 USE [DB_Name] GO if (object_id('SplitIDs') is not null) drop function splitIds; GO IF EXISTS (SELECT * FROM sys.assemblies asms WHERE asms.name = N'SqlServerUtility') DROP ASSEMBL...
NULL.CREATETABLE#Demo ( col1INTNULL, col2ASCOALESCE(col1,0) PRIMARYKEY, col3ASISNULL(col1,0) );-- This statement succeeds because the nullability of the-- ISNULL function evaluates AS NOT NULL.CREATETABLE#Demo ( col1INTNULL, col2ASCOALESCE(col1,0), col3ASISNULL(col1,0) PRIMARY...
CREATE TABLE #Demo ( col1 INT NULL, col2 AS COALESCE (col1, 0) PRIMARY KEY, col3 AS ISNULL(col1, 0) ); -- This statement succeeds because the nullability of the -- ISNULL function evaluates AS NOT NULL. CREATE TABLE #Demo ( col1 INT NULL, col2 AS COALESCE (col1, 0), col...
NULL.CREATETABLE#Demo ( col1INTNULL, col2ASCOALESCE(col1,0) PRIMARYKEY, col3ASISNULL(col1,0) );-- This statement succeeds because the nullability of the-- ISNULL function evaluates AS NOT NULL.CREATETABLE#Demo ( col1INTNULL, col2ASCOALESCE(col1,0), col3ASISNULL(col1,0) PRIMARY...
CREATE TABLE #Demo ( col1 INT NULL, col2 AS COALESCE (col1, 0) PRIMARY KEY, col3 AS ISNULL(col1, 0) ); -- This statement succeeds because the nullability of the -- ISNULL function evaluates AS NOT NULL. CREATE TABLE #Demo ( col1 INT NULL, col2 AS COALESCE (col1, 0), col...
CREATE TABLE #Demo ( col1 INT NULL, col2 AS COALESCE (col1, 0) PRIMARY KEY, col3 AS ISNULL(col1, 0) ); -- This statement succeeds because the nullability of the -- ISNULL function evaluates AS NOT NULL. CREATE TABLE #Demo ( col1 INT NULL, col2 AS COALESCE (col1, 0), col...
NULL.CREATETABLE#Demo ( col1INTNULL, col2ASCOALESCE(col1,0) PRIMARYKEY, col3ASISNULL(col1,0) );-- This statement succeeds because the nullability of the-- ISNULL function evaluates AS NOT NULL.CREATETABLE#Demo ( col1INTNULL, col2ASCOALESCE(col1,0), col3ASISNULL(col1,0) PRIMARY...
CREATE TABLE #Demo ( col1 INT NULL, col2 AS COALESCE (col1, 0) PRIMARY KEY, col3 AS ISNULL(col1, 0) ); -- This statement succeeds because the nullability of the -- ISNULL function evaluates AS NOT NULL. CREATE TABLE #Demo ( col1 INT NULL, col2 AS COALESCE (col1, 0), col...
SQL SELECTCASEWHENxISNOTNULLTHENxELSE1ENDFROM(SELECT(SELECTNullableFROMDemoWHERESomeCol =1)ASx)AST; Compare COALESCE and ISNULL TheISNULLfunction and theCOALESCEexpression have a similar purpose but can behave differently. BecauseISNULLis a function, it's evaluated only once. As described previously...