Key_Column_Usage View
For every constraint (except NOT_NULL) and every index, the used columns and their ordinal positions within this order are listed.
This view is part of the ANSI SQL-2 standard Information Schema.

Column | Data Type | N | Description
RECORD_NUMBER | integer | n | unique identifier for this record of metadata
CONSTRAINT_CATALOG | identifier | n | constraint catalog
CONSTRAINT_SCHEMA | identifier | n | constraint schema
CONSTRAINT_NAME | identifier | n | constraint name
TABLE_CATALOG | identifier | n | table catalog
TABLE_SCHEMA | identifier | n | table schema
TABLE_NAME | identifier | n | table name
COLUMN_NAME | identifier | n | column name
ORDINAL_POSTION | short | n | ordinal position of the column element inside the containing key
CONSTRAINT_TYPE | enumeration | n | contains zero or more of the following attributes: INDEX, PRIMARY, UNIQUE