The ALTER TABLE.. ADD COLUMN statement adds a column to an existing table. This operation is online in TiDB, which means that neither reads or writes to the table are blocked by adding a column ...

You cannot change a character column to numeric and vice versa. To change a column's data type, drop the column and then add it (and its data) again, or use the DATA step. Note: You cannot change the ...

Fixes cockroachdb#32917. This PR adds support for the add column references statement by allowing the foreign key building code to use columns and indexes added in the current txn. The schema changer ...