有没有办法获得一个表格列表,这些表格也会被postgres中的TRUNCATE CASCADE
截断?
例如,假设我们有三个表:
a
b (depends on a)
c (depends on b)
TRUNCATE a CASCADE;
也会截断b
和c
。我们怎么能提前检查这个?
答案 0 :(得分:1)
在this回答的帮助下,您可以通过此查询获取外部表名称
SELECT tc.constraint_name
,tc.table_name
,kcu.column_name
,ccu.table_name AS foreign_table_name
,ccu.column_name AS foreign_column_name
FROM
information_schema.table_constraints AS tc
JOIN information_schema.key_column_usage AS kcu
ON tc.constraint_name = kcu.constraint_name
JOIN information_schema.constraint_column_usage AS ccu
ON ccu.constraint_name = tc.constraint_name
WHERE constraint_type = 'FOREIGN KEY' AND ccu.table_name = 'a'
<强> OR 强>
使用其他查询创建视图
CREATE VIEW vdepend_table
AS
SELECT s1.constraint_name
,s1.table_name
,s1.column_name
,s1.ordinal_position
,s2.table_name_ref
,s2.column_name_ref
,s2.ordinal_position_ref
FROM (
SELECT key_column_usage.constraint_name
,key_column_usage.table_name
,key_column_usage.column_name
,columns.ordinal_position
FROM information_schema.key_column_usage
JOIN information_schema.columns USING (
table_name
,column_name
)
) s1
JOIN (
SELECT constraint_column_usage.constraint_name
,constraint_column_usage.table_name AS table_name_ref
,constraint_column_usage.column_name AS column_name_ref
,cols_ref.ordinal_position AS ordinal_position_ref
FROM information_schema.constraint_column_usage
JOIN information_schema.columns cols_ref ON cols_ref.table_name::TEXT = constraint_column_usage.table_name::TEXT
AND cols_ref.column_name::TEXT = constraint_column_usage.column_name::TEXT
) s2 ON s1.constraint_name::TEXT = s2.constraint_name::TEXT
AND NOT s1.table_name::TEXT = s2.table_name_ref::TEXT;
用法:
select table_name from vdepend_table where table_name_ref='a'