[英]How to set NOT NULL to a column present in all the tables of my database at once?
I'm working with PostgreSQL.我正在使用 PostgreSQL。 I have to set the NOT NULL
property on a column that exists in all the tables of my database.我必须在我的数据库的所有表中存在的列上设置NOT NULL
属性。 I know how to set in one table, using:我知道如何在一张桌子上设置,使用:
ALTER TABLE table_name ALTER COLUMN column_name SET NOT NULL;
But I have about 400 tables in my database, so I need something to do it at once, does anybody the way?但是我的数据库中有大约 400 个表,所以我需要立即执行此操作,有人可以吗?
Thank you in advance!先感谢您!
Use psql
's \gexec
:使用psql
的\gexec
:
SELECT format(
'ALTER TABLE %I.%I ALTER column_name SET NOT NULL;',
table_schema,
table_name
)
FROM information_schema.tables
WHERE table_schema NOT IN ('pg_catalog', 'information_schema') \gexec
Alternatively, you can run the statement, save the output to a script and execute that.或者,您可以运行该语句,将 output 保存到脚本并执行该脚本。
You can also write a DO
statement with PL/pgSQL code that loops through the results of the query and uses EXECUTE
to execute them as dynamic SQL.您还可以使用 PL/pgSQL 代码编写DO
语句,循环查询结果并使用EXECUTE
将它们作为动态 SQL 执行。
As laurenz stated, you can achieve it by executing the ALTER commands in the DO
statement like below,正如 laurenz 所说,您可以通过在DO
语句中执行 ALTER 命令来实现它,如下所示,
DO $$
DECLARE
selectrow record;
BEGIN
FOR selectrow IN
SELECT format(
'ALTER TABLE %I.%I ALTER %s SET NOT NULL;',
table_schema,
table_name,
'my_column'
) AS script
FROM information_schema.tables
WHERE table_schema NOT IN ('pg_catalog', 'information_schema')
LOOP
EXECUTE selectrow.script
END LOOP;
END;
$$;
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