Error Inserting From Inner Join and EXCEPT clause SQL. conversion failed when converting the varchar value 'Error:' to data type int

Question

I have 3 tables

Tabledocs2 LogTable Tabledocs1

I am trying to insert into Tabledocs2 from Tabledocs1 not in Tabledocs2 already.

The LogTable is the intermediate table which contains the columns of Tabledocs1 and Tabledocs2.

Convert on case doesn't catch/ handle this error. " conversion failed when converting the varchar value 'Error:' to data type int"

PRINT 'INSERTING FROM Tabledocs2 INTO Tabledocs1'
        INSERT INTO Tabledocs1 (Log_id, document_name , document_icon , document_body )
        SELECT  CONVERT(INT, CASE WHEN IsNumeric(CONVERT(VARCHAR(12),ID)) = 1 then CONVERT(VARCHAR(12), ID) else 0 End) as int  , document_name , document_icon , document_body 
        FROM LogTable
        INNER JOIN Tabledocs1 
        ON LogTable.detail_ID  = Tabledocs1.detail_ID 
        AND log_ID = @LogID 
        EXCEPT
        (SELECT Log_id, document_name , document_icon , document_body FROM Tabledocs2)--To Avoid duplicates

Answer 1

Perhaps you should convert in the other direction?

INSERT INTO Tabledocs1 (Log_id, document_name , document_icon , document_body )
    SELECT ID, document_name , document_icon , document_body 
    FROM LogTable INNER JOIN
         Tabledocs1 
         ON LogTable.detail_ID  = Tabledocs1.detail_ID 
    WHERE log_ID = @LogID 
    EXCEPT
    (SELECT CAST(Log_id as VARCHAR(12)), document_name , document_icon , document_body
     FROM Tabledocs2
    );--To Avoid duplicates

There may be reasons -- such as leading zeros -- why you would want to convert to a numeric format. However, 12 characters is too long for an integer, so you would need NUMERIC() or BIGINT anyway.