importccl: enable importing MySQL SET columns

[knz]

https://dev.mysql.com/doc/refman/5.7/en/set.html

A SET is a string object that can have zero or more values, each of which must be chosen from a list of permitted values specified when the table is created. SET column values that consist of multiple set members are specified with members separated by commas (,). A consequence of this is that SET member values should not themselves contain commas.

Technically, the MySQL "SET" pseudo-type is a 64-bit bitmask under the hood. Each bit in the bitmask is given a name in the table descriptor.

This can be imported into cockroachdb as an integer.

Epic CRDB-8825

Jira issue: CRDB-4731

[kurokochin]

Hi, I'm interested to work on this. I might need a few pointers regarding what changes needed to be made.

My current understanding:

• We just want to consider SET as an integer (need to made changes in pkg/ccl/importccl/read_import_mysql.go and modify case mysqltypes.Set from throwing error to define the type def.Type = types.Int)
• Need to add test inside everything.sql and modify the expected result in everything.cockroach-schema.sql

cc @knz kindly correct me I'm wrong

Thanks in advance!

[dikshant]

With IMPORT MYSQLDUMP being deprecated: #93660 and Schema Conversion Tool being better for schema migrations, this is no longer needed and can now be closed.