选择空值postgresql的列(Select columns with null values postgresql)

选择空值postgresql的列(Select columns with null values postgresql)

我正在研究一个有22个表格的postgreSQL数据库。 我需要一个查询，它返回空值的列。 可能是一个静态的sql语句，我可以启动到每个表。

我会很高兴得到一些帮助。

最好。

I'm working on a postgreSQL database with 22 table. I need a query which returns the columns with null values. May be a static sql statement that I can launch to each table.

I would be pleased to get some help.

Best.

最满意答案

假设您定期运行VACUUM ANALYZE ， pg_stats.null_frac可以帮助您获取：

--Get columns "filled" entirely with null values SELECT schemaname, tablename, attname, null_frac FROM pg_stats WHERE null_frac = 1.0 AND schemaname = 'yourschema'

Assuming that you run VACUUM ANALYZE periodically, pg_stats.null_frac can help you to get that:

--Get columns "filled" entirely with null values SELECT schemaname, tablename, attname, null_frac FROM pg_stats WHERE null_frac = 1.0 AND schemaname = 'yourschema'