经常和oracle打交道的人都应该遇到会遇到过这么一类需求：
哪些表引用了这个表
这条数据被引用了几次
这张表引用了哪些表，引用的字段是什么
本人也经常遇到这些问题，特别是当删除一条数据总是被告知被引用的时候。于是写了以下外键反查套件：
注： 本套件只支持表中主键列名为ID，ID为NUMBER类型，如果不符合你的需求可自行修改。
用法
-
查询我引用谁
SELECT * FROM TABLE(FK_UTIL.get_refering_stats('TABLE_A')); -
查询谁引用我
SELECT * FROM TABLE(FK_UTIL.get_refered_stats('TABLE_A')); -
查询ID为的某条记录的被引用计数
SELECT * FROM TABLE(FK_UTIL.get_refered_count('TABLE_A', ID)); -
查询某种条件下的被引用计数
-- 查询code为1的某条记录的被引用计数SELECT * FROM TABLE(FK_UTIL.get_refered_count_cond('xb_std_types', 'code', '1')); -
查询某表在某种条件下的被引用情况，并且附带出更详细的信息
SELECT TABLE_A.id, TABLE_A.COLUMN1, TABLE_A.COLUMN2, ..., stats.child_table, stats.refer_countFROM TABLE_A JOIN TABLE(FK_UTIL.get_refered_count_cond('TABLE_A', 'COLUMN', 'VALUE')) statsON stats.parent_id=TABLE_A.id;
安装
执行下列sql语句，安装本套件
CREATE OR REPLACE TYPE fk_stats_row AS object ( child_table varchar2(32), child_table_fk_col varchar2(32), parent_table varchar2(32), parent_table_pk_col varchar2(32));/ CREATE OR REPLACE TYPE fk_stats AS TABLE OF fk_stats_row;/ CREATE OR REPLACE TYPE fk_refered_count_row AS object ( child_table varchar2(32), parent_id NUMBER(19), refer_count NUMBER(19));/ CREATE OR REPLACE TYPE fk_refered_count AS TABLE OF fk_refered_count_row;/ CREATE OR REPLACE TYPE id_array AS TABLE OF NUMBER(19);/ CREATE OR REPLACE package FK_UTILIS -- 获得我所引用的表 FUNCTION get_refering_stats(v_table_name varchar2) RETURN fk_stats; -- 获得所有子表及外键列 FUNCTION get_refered_stats(v_table_name varchar2) RETURN fk_stats; -- 获得所有子表对某个ID的引用条数 FUNCTION get_refered_count(v_parent_table varchar2, v_parent_id NUMBER) RETURN fk_refered_count; -- 获得所有子表对符合条件的某些记录的引用条数 FUNCTION get_refered_count_cond(v_parent_table varchar2, v_cond_col varchar2, v_cond varchar2) RETURN fk_refered_count;END FK_UTIL;/ CREATE OR REPLACE package body FK_UTILIS -- 获得我所引用的表 FUNCTION get_refering_stats(v_table_name varchar2) RETURN fk_stats IS v_ret fk_stats := fk_stats(); BEGIN SELECT CAST( multiset( SELECT a.TABLE_NAME 从表, a.column_name 外键列, b.TABLE_NAME 主表, b.column_name 被引用列 FROM ( SELECT uc.TABLE_NAME, ucc.column_name, uc.r_constraint_name FROM user_constraints uc JOIN user_cons_columns ucc ON uc.constraint_name = ucc.constraint_name WHERE uc.constraint_type='R' ) a, ( SELECT uc.TABLE_NAME, ucc.column_name, uc.constraint_name FROM user_constraints uc JOIN user_cons_columns ucc ON uc.constraint_name = ucc.constraint_name ) b WHERE a.r_constraint_name = b.constraint_name AND a.TABLE_NAME = UPPER(v_table_name) ) AS fk_stats ) INTO v_ret FROM dual; RETURN v_ret; END get_refering_stats; -- 获得所有子表及外键列 FUNCTION get_refered_stats(v_table_name varchar2) RETURN fk_stats IS v_ret fk_stats := fk_stats(); BEGIN SELECT CAST( multiset( SELECT a.TABLE_NAME 从表, a.column_name 外键列, b.TABLE_NAME 主表, b.column_name 被引用列 FROM ( SELECT uc.TABLE_NAME, ucc.column_name, uc.r_constraint_name FROM user_constraints uc JOIN user_cons_columns ucc ON uc.constraint_name = ucc.constraint_name WHERE uc.constraint_type='R' ) a, ( SELECT uc.TABLE_NAME, ucc.column_name, uc.constraint_name FROM user_constraints uc JOIN user_cons_columns ucc ON uc.constraint_name = ucc.constraint_name ) b WHERE a.r_constraint_name = b.constraint_name AND b.TABLE_NAME = UPPER(v_table_name) ) AS fk_stats ) INTO v_ret FROM dual; RETURN v_ret; END get_refered_stats; -- 获得所有子表对某个ID的引用条数 FUNCTION get_refered_count(v_parent_table varchar2, v_parent_id NUMBER) RETURN fk_refered_count IS v_ret fk_refered_count := fk_refered_count(); v_count NUMBER := 0; v_sql varchar2(2000) := ''; BEGIN FOR v_row IN (SELECT * FROM TABLE(get_refered_stats(v_parent_table))) loop v_sql := 'select count(*) from '|| v_row.child_table ||' where ' || v_row.child_table_fk_col || ' = ' || v_parent_id; EXECUTE immediate v_sql INTO v_count; v_ret.extend(1); v_ret(v_ret.COUNT) := fk_refered_count_row(v_row.child_table, v_parent_id, v_count); END loop; RETURN v_ret; END get_refered_count; -- 获得所有子表对符合条件的某些记录的引用条数 FUNCTION get_refered_count_cond(v_parent_table varchar2, v_cond_col varchar2, v_cond varchar2) RETURN fk_refered_count IS v_ret fk_refered_count := fk_refered_count(); v_id_array id_array := id_array(); v_sql varchar2(2000) := ''; BEGIN IF UPPER(v_cond_col) LIKE '%ID' THEN v_sql := 'select cast(multiset(select id from ' || v_parent_table || ' where '|| v_cond_col ||'=' || v_cond || ') as id_array) from dual'; ELSE v_sql := 'select cast(multiset(select id from ' || v_parent_table || ' where '|| v_cond_col ||'=''' || v_cond || ''') as id_array) from dual'; END IF; EXECUTE immediate v_sql INTO v_id_array; FOR id_row IN (SELECT * FROM TABLE(v_id_array)) loop FOR count_row IN (SELECT * FROM TABLE(get_refered_count(v_parent_table, id_row.column_value))) loop v_ret.extend(1); v_ret(v_ret.COUNT) := fk_refered_count_row(count_row.child_table, count_row.parent_id, count_row.refer_count); END loop; END loop; RETURN v_ret; END get_refered_count_cond;END FK_UTIL;/