是否有一种方法使用SQL列出给定表的所有外键?我知道表名/模式,我可以把它插入。
当前回答
只需替换'您的表名'在下面的查询与您的表名。
简短但贴心的赞,如果对你有用的话。
select * from information_schema.key_column_usage
where constraint_catalog=current_catalog and table_name='your_table_name'
and position_in_unique_constraint notnull;
其他回答
SELECT conrelid::regclass AS table_name,
conname AS foreign_key,
pg_get_constraintdef(oid)
FROM pg_constraint
WHERE contype = 'f'
AND connamespace = 'public'::regnamespace
ORDER BY conrelid::regclass::text, contype DESC;
https://soft-builder.com/how-to-list-all-foreign-keys-in-postgresql-database
使用Key所引用的主键的名称并查询information_schema:
select table_name, column_name
from information_schema.key_column_usage
where constraint_name IN (select constraint_name
from information_schema.referential_constraints
where unique_constraint_name = 'TABLE_NAME_pkey')
这里'TABLE_NAME_pkey'是外键引用的主键的名称。
选择的答案不为我工作,所以张贴我的sql工作。
select
con.conname as constraint_name,
src_schema.nspname as source_schema,
source.relname as source_table,
source_col.attname as source_column,
trg_schema.nspname as target_schema,
target.relname as target_table,
target_col.attname as target_column
from
pg_constraint con
inner join
pg_class source on source.oid = con.conrelid
inner join
pg_attribute source_col on source_col.attrelid = con.conrelid and source_col.attnum = con.conkey[1] and source_col.attisdropped = false
inner join
pg_namespace src_schema on src_schema.oid = source.relnamespace
inner join
pg_class target on target.oid = con.confrelid
inner join
pg_attribute target_col on target_col.attrelid = con.confrelid and target_col.attnum = con.confkey[1] and source_col.attisdropped = false
inner join
pg_namespace trg_schema on trg_schema.oid = target.relnamespace
为了扩展Martin的精彩回答,这里有一个查询,它允许您根据父表进行过滤,并显示每个父表的子表的名称,以便您可以根据父表中的外键约束查看所有依赖的表/列。
select
con.constraint_name,
att2.attname as "child_column",
cl.relname as "parent_table",
att.attname as "parent_column",
con.child_table,
con.child_schema
from
(select
unnest(con1.conkey) as "parent",
unnest(con1.confkey) as "child",
con1.conname as constraint_name,
con1.confrelid,
con1.conrelid,
cl.relname as child_table,
ns.nspname as child_schema
from
pg_class cl
join pg_namespace ns on cl.relnamespace = ns.oid
join pg_constraint con1 on con1.conrelid = cl.oid
where con1.contype = 'f'
) con
join pg_attribute att on
att.attrelid = con.confrelid and att.attnum = con.child
join pg_class cl on
cl.oid = con.confrelid
join pg_attribute att2 on
att2.attrelid = con.conrelid and att2.attnum = con.parent
where cl.relname like '%parent_table%'
SELECT
conrelid::regclass AS table_from,
conname,
pg_get_constraintdef(oid) as condef
FROM pg_catalog.pg_constraint r
也适用于所有约束条件。例如,使用pysql:
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