无法将此查询 function 转换为 Amazon Redshift

Question

I'm trying to migrate/create functions from a MySQL Database to Amazon Redshift. I tried to use some tools to convert MySQL to Redshift but this line isn't working:

DECLARE saldoAtual, saldoInicial, idPerfil INT default 0;

I keep getting an error saying there is something wrong with "INT".

Can anyone help me?

Answer 1

You are going to need to pop up one level and evaluate what you My SQL code is doing. You see DECLARE in this case on MySQL is declaring a variable and setting its type and default value. The DECLARE statement on Redshift is used to define a cursor for manipulating query output. These are two completely different actions that just happen to use the same term. These don't map.

Further, Redshift doesn't have variable that you define and use at the SQL level. Redshift does not have an operating environment like many transactional database have. It is focused on executing queries, not performing procedural scripts around these queries. It has a different division of labor than MySQL. You see Redshift is part of a larger computing environment, AWS, and these procedural actions are expected to be run outside the database using tools like Lambda, Glue, or Data Pipeline.

Redshift does have stored procedures and depending on your use case you may be able to map you code into a stored procedure. These really aren't interchangeable but you may be able to get away with it. Otherwise you will need to evaluate what your MySQL code is doing and map it to the correct tool level at AWS.