在python中填充n级PostgreSQL表
我很难思考如何填充一个n级表(在我的例子中是3级),我使用python从查询中获取数据,但我不确定如何填充我的新表在python中填充n级PostgreSQL表,python,sql,postgresql,database-design,sql-insert,Python,Sql,Postgresql,Database Design,Sql Insert,我很难思考如何填充一个n级表(在我的例子中是3级),我使用python从查询中获取数据,但我不确定如何填充我的新表resources,因为它引用自身。如对该方法有任何反馈,将不胜感激 在python文件中运行以下查询后,我得到下表 SELECT distinct c.table_catalog AS "Database", c.table_schema AS "Schema", c.table_name AS "Table" FROM information_schema.columns c W
resources
,因为它引用自身。如对该方法有任何反馈,将不胜感激
在python文件中运行以下查询后,我得到下表
SELECT distinct c.table_catalog AS "Database", c.table_schema AS "Schema", c.table_name AS "Table"
FROM information_schema.columns c
WHERE c.table_schema != 'information_schema' AND c.table_schema != 'pg_catalog' AND c.table_schema != 'pg_internal' AND c.table_schema not like '% %'
ORDER BY c.table_schema, c.table_name;
Database Schema Table
____________________________________
dev BigBangTheory SomeTable1
dev BigBangTheory SomeTable2
dev BigBangTheory SomeTable3
dev Walle AnotherTable100
dev Walle AnotherTable200
dev StarWars SpaceTablexxx
dev StarWars SpaceTableyyy
stage BigBangTheory SomeTable1
stage BigBangTheory SomeTable2
stage BigBangTheory SomeTable3
stage Walle AnotherTable100
stage Walle AnotherTable200
stage StarWars SpaceTablexxx
stage StarWars SpaceTableyyy
我还有另一个表,我想用上面的结果填充它。
我要填充的表如下所示:
CREATE TABLE IF NOT EXISTS resources
(
"id" SERIAL NOT NULL PRIMARY KEY,
"type" varchar(100) NOT NULL,
"name" varchar(100) NOT NULL,
"parent" int,
FOREIGN KEY (parent) REFERENCES resources (id)
);
因此,我的目标是使表资源如下所示:
id type name parent
____________________________________________________
1 database dev NULL
2 schema BigBangTheory 1
3 table SomeTable1 2
4 table SomeTable2 2
5 table SomeTable3 2
6 schema Walle 1
7 table AnotherTable100 6
8 table AnotherTable200 6
9 schema StarWars 1
10 table SpaceTablexxx 9
11 table SpaceTableyyy 9
12 database stage NULL
13 schema BigBangTheory 12
14 table SomeTable1 13
15 table SomeTable2 13
16 table SomeTable3 13
17 schema Walle 12
18 table AnotherTable100 17
19 table AnotherTable200 17
20 schema StarWars 12
21 table SpaceTablexxx 20
22 table SpaceTableyyy 20
提前谢谢你!所有反馈都被视为一个开端:您可以直接从信息\u模式表
而不是信息\u模式列
(每个表只有一行,因此需要不同的
)
然后:在Postgres中,您可以在单个查询中执行您想要的操作,使用带有的级联公共表表达式,将子句返回到Postgres中的insert
语句。能
逻辑是首先插入顶级对象(数据库)并返回生成的序列,然后插入模式(使用数据库序列),最后插入表
with
info as (
select c.table_catalog, c.table_schema, c.table_name
from information_schema.tables
where
c.table_schema not in ('information_schema', 'pg_catalog', 'pg_internal')
and c.table_schema not like '% %'
),
dbs as (
insert into resources (type, name)
select distinct 'database', table_catalog
from info
returning id, name
),
schemas as (
insert into resources(type, name, parent)
select distinct 'schema', i.table_schema, d.id
from info i
inner join dbs d on d.name = i.table_catalog
returning id, name, parent
)
insert into resources(type, name, parent)
select 'table', table_name, s.id
from info i
inner join schemas s on s.name = i.table_schema
inner join dbs d on d.id = s.parent and d.name = i.table_catalog
注意最后一个insert
在schema
和dbs
上连接;这是为了正确处理位于不同模式中的“同音异义”表
是一个演示(我使用了一个表来模拟初始查询的结果)