oracle表结构查询

SELECT A.CNAME,

A.COLTYPE,

(SELECT B.CONSTRAINT_TYPE

FROM USER_CONSTRAINTS B, USER_CONS_COLUMNS C

WHERE B.CONSTRAINT_NAME = C.CONSTRAINT_NAME

AND C.TABLE_NAME = B.TABLE_NAME

AND B.OWNER = C.OWNER

AND B.TABLE_NAME = A.TNAME

AND B.CONSTRAINT_TYPE = 'P'

AND C.COLUMN_NAME = A.CNAME) CONSTRAINT_TYPE

FROM COL A

WHERE A.TNAME = ?