IF 语句中间的 GO 命令

我正在寻找有关创建表的信息，仅当它们在当前数据库中不存在时（以便能够在可能或可能没有它们的不同数据库中创建它）并发现这两个有用的主题

• SQL Server：检查表是否存在 https://stackoverflow.com/questions/167576/sql-server-check-if-table-exists
• 如何检查SQL Server表中是否存在列 https://stackoverflow.com/questions/133031/how-to-check-if-column-exists-in-sql-server-table

所以我做了这个查询

IF (NOT EXISTS (SELECT * 
             FROM INFORMATION_SCHEMA.TABLES 
             WHERE TABLE_NAME = 'EMAILCONTAS'))
BEGIN
SET ANSI_NULLS ON
GO

SET QUOTED_IDENTIFIER ON
GO

SET ANSI_PADDING ON
GO

CREATE TABLE [dbo].[EMAILCONTAS](
    [NRSEQEMAILCONTAS] [numeric](8, 0) NOT NULL,
    [CDEMAILCONTAS] [varchar](40) NULL,
    [MSGEMAILCONTAS] [varchar](4000) NOT NULL,
    [CCOEMAIL] [varchar](100) NULL,
    [NRSEQOPERADORA] [numeric](8, 0) NOT NULL,
 CONSTRAINT [PK_EMAILCONTAS] PRIMARY KEY CLUSTERED 
(
    [NRSEQEMAILCONTAS] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
) ON [PRIMARY]

GO

SET ANSI_PADDING OFF
GO

ALTER TABLE [dbo].[EMAILCONTAS]  WITH CHECK ADD FOREIGN KEY([NRSEQOPERADORA])
REFERENCES [dbo].[OPERADORA] ([NRSEQOPERADORA])
GO

ALTER TABLE [dbo].[EMAILCONTAS]  WITH CHECK ADD  CONSTRAINT [FK_EMAILCONTAS_OPERADORA] FOREIGN KEY([NRSEQOPERADORA])
REFERENCES [dbo].[OPERADORA] ([NRSEQOPERADORA])
GO

ALTER TABLE [dbo].[EMAILCONTAS] CHECK CONSTRAINT [FK_EMAILCONTAS_OPERADORA]
GO
END

但是当我执行它时，我在错误列表中得到了这个。

Msg 102, Level 15, State 1, Line 5
Incorrect syntax near 'ON'.

但无论如何它都会创建我的表（我输入了“从人员中选择*；”在上面的代码之后，检查错误是否会阻止下一个脚本的编译。并且错误阻止了它。显示此错误：

Msg 156, Level 15, State 1, Line 3
Incorrect syntax near the keyword 'Select'.

有办法避免吗？）。当我执行此查询并且表已经存在时，我收到以下错误。

Msg 102, Level 15, State 1, Line 5
Incorrect syntax near 'ON'.
Msg 2714, Level 16, State 6, Line 2
There is already an object named 'EMAILCONTAS' in the database.
Msg 2714, Level 16, State 5, Line 2
There is already an object named 'FK_EMAILCONTAS_OPERADORA' in the database.
Msg 1750, Level 16, State 0, Line 2
Could not create constraint. See previous errors.

我怎样才能做到这一点而不出现这些错误？有没有办法可以毫无问题地创建多个这样的代码？我究竟做错了什么？

GO类似于脚本的结尾；你可以删除GOs 来自 BEGIN-END 语句内。

如果您绝对需要GO在代码中，您可以将查询分解为：

IF (criteria)
BEGIN
    ...
END

GO

IF (newcriteria)
BEGIN
    ...
END