常用的SQL语句

1.查询数据表名称、字段、字段说明

SELECT
t.[name] AS 表名,
c.[name] AS 字段名,
cast(ep.[value] as nvarchar(200)) AS [字段说明]
FROM sys.tables AS t
INNER JOIN sys.columns
AS c ON t.object_id = c.object_id
LEFT JOIN sys.extended_properties AS ep
ON ep.major_id = c.object_id AND ep.minor_id = c.column_id WHERE ep.class =1
AND t.name='TableName'

2. SQL自定义函数和递归with（注意：with递归默认层级是：100）
ALTER function [dbo].[fun_GetMemNewsGroupParentIDs](@NewGrpIDs nvarchar(500))
returns @t table(NewGrpID int,ParentID int)
as
begin
WITH T AS
(
SELECT NewGrpID,ParentID FROM MemNewsGroup
WHERE charindex(','+ltrim(NewGrpID)+',',','+@NewGrpIDs+',') > 0
UNION ALL
SELECT A.NewGrpID,A.ParentID
FROM MemNewsGroup AS A JOIN T AS B ON A.NewGrpID = B.ParentID
)
insert into @t select distinct NewGrpID,ParentID from T
RETURN
end