T-SQL constructs not handled:
- String concatenation: since + is used in T-SQL both for concatenation strings and for addition you need to know the datatype of the arguments to know if it should be converted. The tool does no attempt to do this, even if some cases (text constants, declared variables or parameters) would be quite easy.
- GOTO's and labels: The code I converted contains a lot of GOTO's. A very common construction is:
SELECT @p_err_num = @@ERROR
IF (@p_err_num <> 0) GOTO OnError
RETURN( @p_err_num )
I don't want to convert this! The MySQL/ANSI error handler is so much better, and there is no GOTO. So, the goto's and lables will be commented out and you will have to convert it by hand.
- Dateadd: MySql has the same functionality in the date_add function, but parameter order is different. Since function calls can be nested, the tool would need to parse the code more than it does to be able to fix this. This is on my list, but not yet implemented.
- Select TOP: This corresponds to the MySQL LIMIT clause. But since T-SQL allows parameters perhaps using the SET SQL_SELECT_LIMIT would be better. On the other hand this would be complicated in cursors.. Since we have only very few procedures where this is used, we do it by hand so far. Perhaps in a coming release...
- Dynamic SQL: T-SQL execute could be replaced by MySQL PREPARE/ EXCUTE/ DROP PREPARE but the command would be a text string, and the tool does not, and should not, convert text strings. Probably you should check why you are using dynamic SQL in your code, and consider using another approach, or convert the text strings to MySQL by hand. Dynamic SQL is advanced and should only be used if you really need it.