sql-server - SQL Server 2008 合并语句检查并插入记录是否不存在

Question

我试图通过 sql 脚本检查是否存在记录的某些条件来将记录添加到表中。我正在尝试使用合并语句。它不工作无法找出我哪里出错了。有人可以帮我弄这个吗？。谢谢

MERGE Categories As target
    USING (
    SELECT CategoryKey 
    From Categories where CategoryName = 'TestName'
    ) AS source on (source.CategoryKey = target.CategoryKey)
WHEN Not Matched THEN
    INSERT VALUES ('TestName');

Answer 1

这将完成这项工作:

MERGE Categories As target
USING (SELECT 'TestName' AS CategoryName) AS source 
    ON (source.CategoryName = target.CategoryName)
WHEN NOT MATCHED THEN
    INSERT (CategoryName) VALUES ('TestName');