SQL Server add single quotation marks

The use of "'" (single quotation marks): In SQL Server, two "'" (single quotation marks) in the case of stitching strings, that is, the concatenation of a "'" single quote string.

SELECT TOP 1 " '"+CONVERT(nvarchar( -), keyID)+" '"Name1 fromRel_productstocklock with(NOLOCK)WHEREKeyId is  not NULLSELECT TOP 1 " '"+CONVERT(nvarchar( -), keyID)+" ",'Name2 fromRel_productstocklock with(NOLOCK)WHEREKeyId is  not NULLSELECT " '"Name3;SELECT '123" "Name4;SELECT '123'+"'Name5;SELECT  '"123"'Name6;SELECT TOP 1 '123'+AreaName Name7 fromdbo. Dim_area;SELECT TOP 1 '123" "+AreaName Name8 fromdbo. Dim_area;SELECT TOP 1 '123" "+AreaName+"'Name9 fromdbo. Dim_area;SELECT TOP 1 '123" "+AreaName+" '"Name10 fromDbo. Dim_area;

https://www.cnblogs.com/zhaosw/p/6088040.html questions about SQL stitching strings

SQL Server add single quotation marks