SQL uses 1 to indicate whether the query result is null & A simple method to determine whether a table exists

Create table # staff (id int)
Insert into # staff values (9)
If exists (select 1 from # staff where id = 9)
Print ('pass ')
Else
Print ('fail ')
Drop table # staff

Change the value of where id = 9 to another value and output fail. You can understand the other values.

 

1 is not a field of the temporary table # class, but a tag used to judge whether the query is empty.

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Determine whether the table exists:

If not object_id ('table name') is null

Drop table Name

If exists (SELECT * from sysobjects where id = 'table name'

If exists (select * from dbo. sysobjects where id = object_id (n' [dbo]. [forums_User_CreateUpdateDelete] ') and OBJECTPROPERTY (id, n'isprocedure') = 1)
Drop procedure [dbo]. [forums_User_CreateUpdateDelete]