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
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查询我引用谁
SELECT * FROM TABLE(FK_UTIL.get_refering_stats('TABLE_A'));
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查询谁引用我
SELECT * FROM TABLE(FK_UTIL.get_refered_stats('TABLE_A'));
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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));
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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'));
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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_count FROM TABLE_A JOIN TABLE(FK_UTIL.get_refered_count_cond('TABLE_A','COLUMN','VALUE')) stats ON 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_UTIL IS -- 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_UTIL IS -- 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,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,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 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; /