information_schema.key_column_usage.position_in_unique_constraint

Note:

For foreign keys, the position in the unique constraint.

Note:

The unique constraint and the primary key constraint are empty. For foreign key constraints, this column is the position of the referenced table's key.

Note:

For a foreign-key constraint, ordinal position of the referenced column within its unique constraint (count starts at 1); otherwise null

Note:

For a foreign-key constraint, ordinal position of the referenced column within its unique constraint (count starts at 1); otherwise null

Note:

For foreign key constraints, ordinal position of the referenced column within its uniqueness constraint (begins at 1).

Note:

For Foreign Key constraints, ordinal position of the referenced column within its Unique constraint (begins at 1).