Oracle数据库中，知道一张表，查询与其有主外键关系的表

          --查外键表NC56.CSCI有无对应的主键表
           SELECT a.owner,
                  A.TABLE_NAME      primary_table_name,
                  A.CONSTRAINT_NAME primary_table_key_name,
                  b.owner,
                  B.TABLE_NAME      foreign_table_name,
                  B.CONSTRAINT_NAME foreign_table_foreign_key_name,
                  B.STATUS          foreign_table_foreign_key_stat
             FROM DBA_CONSTRAINTS A, DBA_CONSTRAINTS B
            WHERE A.CONSTRAINT_NAME = B.R_CONSTRAINT_NAME
              and B.CONSTRAINT_TYPE = 'R'
              AND b.TABLE_NAME = 'CSCI' and a.owner='NC56' and b.owner='NC56'
            ORDER BY 1, 2, 3, 4;

           --查主键表NC56.CBH有无对应的外键表           SELECT a.owner,                 A.TABLE_NAME      primary_table_name,                  A.CONSTRAINT_NAME primary_table_key_name,                  b.owner,                  B.TABLE_NAME      foreign_table,                  B.CONSTRAINT_NAME foreign_table_foreign_key_name,                  B.STATUS          foreign_table_foreign_key_stat             FROM DBA_CONSTRAINTS A, DBA_CONSTRAINTS B            WHERE A.CONSTRAINT_NAME = B.R_CONSTRAINT_NAME              and B.CONSTRAINT_TYPE = 'R'              AND a.TABLE_NAME = 'CBH' and a.owner='NC56' and  b.owner='NC56'            ORDER BY 1, 2, 3, 4;