mysql常用查询

1.查询表结构

select
	ordinal_position "序号",
	column_name "字段",
	column_type "字段类型",
	column_key "约束",
	is_nullable "可空",
	column_default "默认值",
	extra "自增性",
	column_comment "注释"
from
	(
	select
		t1.table_name,
		t1.table_comment,
		t2.ordinal_position,
		t2.column_name,
		t2.column_type,
		t2.column_key,
		t2.extra,
		t2.is_nullable,
		t2.column_default,
		t2.column_comment
	from
		information_schema.tables t1
	left join information_schema.columns t2
on
		t1.table_name = t2.table_name
	where
		t1.table_schema = 'sjsg'
	order by
		t1.table_name,
		t2.ordinal_position) t
where table_name='B_RS_DW'