informix 约束检查

--查询 表 tbl_demo 引用的表
SELECT
	a.tabname, constrname, d.tabname 
FROM
	systables a, sysconstraints b, sysreferences C, systables d 
WHERE
	b.constrtype = 'R' AND
	a.tabid = b.tabid AND
	b.constrid = C.constrid AND
	C.ptabid = d.tabid AND
	d.tabname = ' tbl_demo';

--查询引用了 tbl_demo 的表
SELECT
	a.tabname, constrname, d.tabname 
FROM
	systables a, sysconstraints b, sysreferences C, systables d 
WHERE
	b.constrtype = 'R' AND
	a.tabid = b.tabid AND
	b.constrid = C.constrid AND
	C.ptabid = d.tabid AND
	d.tabname = ' tbl_demo';