IF-THEN-ELSE：创建/截断表-SQL Server

Question

I am attempting to create a backup table without having to re-create it every single time. If the table already exists in the next run then it should simply truncate the table.

But it doesn't seem to be working. It says backup_reportsettings is already in the database. Can anyone assist me with this?

--Only re-create table if table does not exist otherwise truncate the existing table.   
IF NOT EXISTS (SELECT * FROM [Misc].sys.tables where name= 'dbo.backup_reportsettings')
    CREATE TABLE [MISC].dbo.backup_reportsettings 
    (
        [datestamp] [datetime] NULL,
        [reportsettingid] [char](8) NOT NULL,
        [description] [char](30) NOT NULL,
        [formname] [char](30) NOT NULL,
        [usersid] [char](8) NOT NULL,
        [settings] [text] NOT NULL,
        [notes] [varchar](255) NOT NULL,
        [userdefault] [char](1) NOT NULL
    )
ELSE 
    TRUNCATE TABLE [Misc].dbo.backup_reportsettings;

What am I doing wrong? Note: this is done within a transaction.

Answer 1

Object names in sys.tables don't have the schema as part of the name. Remove the table schema when verifying whether the table exists:

IF NOT EXISTS (SELECT * FROM [Misc].sys.tables where name= 'backup_reportsettings')

Answer 2

Despite the use of IF , SQL Server needs to Parse/Compile all the statements in your script, so when it sees a CREATE TABLE statement it will give you a compilation error if the table already exists, even though the IF would prevent that code from being executed when that is the case.

The way to get around this is to put your CREATE TABLE statement in dynamic SQL, which will not be parsed/compiled before execution.