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 ...

Specifies whether the column can accept NULL values. Columns that do not allow NULL values can be added only if they have a default specified. If the new column allows NULL values and no default is ...

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 ...