Question

I have a query in SQL Server:

insert into [Sha1]( 
       [IDTbl]
      ,[IDTbl_old]
      ,[IDold]
      ,[WordsAsl])
 (SELECT  [IDTbl]
      ,[IDTbl_old]
      ,[IDold]
      ,[WordsAsl]
  FROM [Sha2])

How to solve this error:

Cannot insert the value NULL into column ‘IDTbl’, table ‘Sha1’; column
does not allow nulls. INSERT fails.

Answer 1

The other option besides just excluding those rows from your SELECT that contain NULL is to use the ISNULL() function to provide a default values instead of NULL:

 INSERT INTO dbo.Sha1(IDTbl, IDTbl_old, IDold, WordsAsl)
     SELECT  
        ISNULL(IDTbl, 42),
        IDTbl_old,
        IDold,
        WordsAsl
     FROM dbo.Sha2

Here I stipulated that should the IDTbl value from dbo.Sha2 be NULL, then the SELECT should return 42 instead (and thus insert this value into dbo.Sha1 instead of NULL).