SQL语法错误将过程创建为外部过程

问题：如果我将If not exists作为外部名称语句添加到create过程中，我会得到一个语法错误。。。为什么？ 如果我分别运行这两个语句，它们都可以正常工作

IF  NOT EXISTS 
(
    SELECT * FROM sys.objects 
    WHERE object_id = OBJECT_ID(N'PriceSum') 
    AND type in (N'P', N'PC')
)
CREATE PROCEDURE PriceSum(@sum int OUTPUT)
     AS EXTERNAL NAME MyFirstUdp.[SQL_CLRdll.MySQLclass].PriceSum

试一试

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我认为它不喜欢在

创建过程之前和同一批中的东西。
因为创建过程必须是批中的第一条语句

要么先删除进程，要么使用动态SQL

IF  NOT EXISTS 
(
    SELECT * FROM sys.objects 
    WHERE object_id = OBJECT_ID(N'PriceSum') 
    AND type in (N'P', N'PC')
)
exec('CREATE PROCEDURE PriceSum(@sum int OUTPUT)
     AS EXTERNAL NAME MyFirstUdp.[SQL_CLRdll.MySQLclass].PriceSum')

你也可以颠倒逻辑

    IF  EXISTS 
    (
        SELECT * FROM sys.objects 
        WHERE object_id = OBJECT_ID(N'PriceSum') 
        AND type in (N'P', N'PC')
    )

    DROP PROCEDURE PriceSum
    GO --this ends the batch, so the create statement below is fine

    CREATE PROCEDURE PriceSum(@sum int OUTPUT)
AS EXTERNAL NAME MyFirstUdp.[SQL_CLRdll.MySQLclass].PriceSum
  GO

    IF  EXISTS 
    (
        SELECT * FROM sys.objects 
        WHERE object_id = OBJECT_ID(N'PriceSum') 
        AND type in (N'P', N'PC')
    )

    DROP PROCEDURE PriceSum
    GO --this ends the batch, so the create statement below is fine

    CREATE PROCEDURE PriceSum(@sum int OUTPUT)
AS EXTERNAL NAME MyFirstUdp.[SQL_CLRdll.MySQLclass].PriceSum
  GO