1、查询某数据库中表的总数
select count(*) from information_schema.tables where table_schema=‘dbname‘;
2、仅占一列显示某数据库中的所有表名
select group_concat(table_name) from information_schema.tables where table_schema=‘dbname’;
3、查询某表中有几行
select count(*) from information_schema.COLUMNS where table_schema = ‘dbname‘ AND table_name = ‘tablename‘;
4、仅占一列显示某表中的所有字段名
select group_concat(COLUMN_NAME) from information_schema.COLUMNS where table_name = ‘tablename‘;
5、查询第一行记录
select * from ‘tablename‘ limit 1;
6、查询第n行到第m行记录
select * from ‘tablename‘ limit m,n;(n<=m)
7、查询第n行记录
select * from ‘tablename‘ limit n-1,1;
8、查询前n行记录
-- 方法一 select * from ‘tablename‘ limit 0,n; -- 方法二 select * from ‘tablename‘ limit n;
9、查询后n行记录
-- 倒序排序,取前n行 id为自增形式 select * from ‘tablename‘ order by id desc dlimit n;
10、查询一条记录($id)的下一条记录
select * from ‘tablename‘ where id>$id order by id asc dlimit 1
11、查询一条记录($id)的上一条记录
select * from ‘tablename‘ where id<$id order by id desc dlimit 1
原文:https://www.cnblogs.com/soldierback/p/11255852.html