MSSQL

DECLARE @dbname nvarchar(128)
SET @dbname = N‘database_name‘

IF NOT EXISTS (SELECT name FROM master.dbo.sysdatabases
     WHERE (‘[‘ + name + ‘]‘ = @dbname OR name = @dbname))
BEGIN
     CREATE DATABASE TuoTuo;
END

GO

IF (EXISTS (SELECT * 
                 FROM INFORMATION_SCHEMA.TABLES 
                 WHERE TABLE_SCHEMA = ‘TheSchema‘ 
                 AND  TABLE_NAME = ‘TheTable‘))
BEGIN
    --Do Stuff
END

MSSQL

原文：http://www.cnblogs.com/swlin/p/6523363.html