SqlServer function usage

SqlServer removes duplicate queries for the first data:

　　select ID from(

　　　　select *, row_number() over (partition by SynCode order by id) as RowNum  from syn_table

　　) s  where s.RowNum = 1

 

SqlServer merge rows separated by commas:

　　SELECT name,LEFT(ItemName,LEN(ItemName)-1) FROM (

　　SELECT name,

　　　　(SELECT name+',' FROM Base_BarcodeGroup c WHERE c.NAME=b.Name FOR XML PATH('')

　　)AS ItemName  FROM  Base_BarcodeGroup as b  GROUP BY   name

 　   )AS a

 

SqlServer string in query

　　DECLARE @UnitCode VARCHAR(50)='1,2,3'

　　select * from dbo.Table1 where PATINDEX('%,'+RTRIM(TestNo)+',%',','+@UnitCode+',')>0