显示数据库 table 名称及其列号
Showing database table names and their column numbers
所以我想看看我的每个 table 在数据库库中有多少列。
我用
select * from information_schema.tables where table_schema = 'library';
查看名称和行数,但是,我不确定如何让它也显示列。事实上,我只需要姓名和列号,但我也不确定如何要求查看姓名。我试过了
show tables from information_schema.tables where table_schema = 'library';
但我想这绝对是错误的,因为也会出现错误
您可以使用 information_schema.columns
:
select t.*, c.*
from information_schema.tables t join
information_schema.columns c
on t.table_schema = c.table_schema and t.table_name = c.table_name
where t.table_schema = 'library';
已解决:
SELECT table_name, COUNT(*) FROM information_schema.columns WHERE table_schema = 'Library' Group by table_name;
所以我想看看我的每个 table 在数据库库中有多少列。
我用
select * from information_schema.tables where table_schema = 'library';
查看名称和行数,但是,我不确定如何让它也显示列。事实上,我只需要姓名和列号,但我也不确定如何要求查看姓名。我试过了
show tables from information_schema.tables where table_schema = 'library';
但我想这绝对是错误的,因为也会出现错误
您可以使用 information_schema.columns
:
select t.*, c.*
from information_schema.tables t join
information_schema.columns c
on t.table_schema = c.table_schema and t.table_name = c.table_name
where t.table_schema = 'library';
已解决:
SELECT table_name, COUNT(*) FROM information_schema.columns WHERE table_schema = 'Library' Group by table_name;