有时候查询出的某一列结果要作为其他数据库查询条件，必须要做拼接转换
方法：
SELECT [id] = stuff((SELECT distinct ',''' + t.id + '''' FROM table t WHERE t.id = 1 FOR xml path ('')),1,1,'');
方法使用如下：
SELECT [Id] = STUFF((SELECT DISTINCT ',''' + Ld + '''' FROM BaseMeterFieldType AS b WHERE b.MeterId IN (SELECT Id FROM BaseTree WHERE CompanyId = '071B4795-E124-E711-80EA-C979862AE7CB') FOR xml PATH('')),1,1,'');
执行结果：
以上报错是由于id为GUID，且id需要小写，所以需要进行类型转换，方法如下：
SELECT [Id] = STUFF((SELECT DISTINCT ',''' + CAST(LOWER(b.Id) AS VARCHAR(4000)) + '''' FROM BaseMeterFieldType AS b WHERE b.MeterId IN (SELECT Id FROM BaseTree WHERE CompanyId = '071B4795-E124-E711-80EA-C979862AE7CB') FOR xml PATH('')),1,1,'');
执行结果：
