36.32. key_column_usage

檢視表 key_column_usage 列出目前資料庫中受到某些唯一、主鍵或外部鍵限制的所有欄位。此檢視表中不包括 check constraints。僅顯示目前使用者可以透過成為擁有者或具有某些權限存取的那些欄位。

Table 36.30. key_column_usage Columns

Name	Data Type	Description
constraint_catalog	sql_identifier	Name of the database that contains the constraint (always the current database)
constraint_schema	sql_identifier	Name of the schema that contains the constraint
constraint_name	sql_identifier	Name of the constraint
table_catalog	sql_identifier	Name of the database that contains the table that contains the column that is restricted by this constraint (always the current database)
table_schema	sql_identifier	Name of the schema that contains the table that contains the column that is restricted by this constraint
table_name	sql_identifier	Name of the table that contains the column that is restricted by this constraint
column_name	sql_identifier	Name of the column that is restricted by this constraint
ordinal_position	cardinal_number	Ordinal position of the column within the constraint key (count starts at 1)
position_in_unique_constraint	cardinal_number	For a foreign-key constraint, ordinal position of the referenced column within its unique constraint (count starts at 1); otherwise null