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_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, 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;
/
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