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'更多推荐
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