判断列名是否存在

MS SQL Server写动态SQL时，比如动态创建表，修改表，添加字段，我们需要判断字段是否存在。

你可以参考下面自定义函数：

源代码：

SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO

-- =============================================
-- Author:      Insus.NET
-- Blog:        https://insus.cnblogs.com
-- Create date: 2019-05-29
-- Update date: 2019-05-29
-- Description: 判断列名是否存在
-- =============================================
CREATE FUNCTION [dbo].[usp_IsExistsColumn]
(
    @TABLE_CATALOG SYSNAME,
    @TABLE_SCHEMA SYSNAME,
    @TABLE_NAME SYSNAME,
    @COLUMN_NAME SYSNAME
)
RETURNS BIT
BEGIN    
    DECLARE @isExists BIT = 0
    IF EXISTS(SELECT TOP 1 1 FROM [tempdb].[sys].[columns] WHERE object_id = object_id(@TABLE_CATALOG + N'.'+ @TABLE_SCHEMA + N'.' + @TABLE_NAME) AND [name] = @COLUMN_NAME)
    OR EXISTS(SELECT TOP 1 1 FROM [sys].[columns] WHERE object_id = object_id(@TABLE_CATALOG + N'.'+ @TABLE_SCHEMA + N'.' + @TABLE_NAME) AND [name] = @COLUMN_NAME)    
        SET @isExists = 1
    RETURN @isExists
END
GO