查询语句格式
1 SELECT [STRAIGHT_JOIN] [SQL_SMALL_RESULT] [SQL_BIG_RESULT] [HIGH_PRIORITY] 2 [DISTINCT | DISTINCTROW | ALL] 3 select_expression,... 4 [INTO {OUTFILE | DUMPFILE} 'file_name' export_options] 5 [FROM table_references 6 [WHERE where_definition] 7 [GROUP BY col_name,...] 8 [HAVING where_definition] 9 [ORDER BY {unsigned_integer | col_name | formula} [ASC | DESC] ,...] 10 [LIMIT [offset,] rows] 11 [PROCEDURE procedure_name] ]
1.查询所有数据：
select * from table;
2.查询行：
select * from table where (字段名1=‘xx’ and 字段名2!='xx' ) or 字段名3>100;
3.查询列：
select 字段1,字段2,字段3... from table;
4.查询排序行：
正序：select * from table order by 字段名1,字段名2；(可按多字段优先级排序)
倒序：select * from table order by 字段名1,字段名2 desc;(可按多字段优先级排序)
5.日期计算：（日期函数）
1 mysql> select * from user; 2 +----+------+----------+------+------+---------------------+---------------------+ 4 | Id | name | nikename | sex | age | birth_date | goodbye_date 5 | 6 +----+------+----------+------+------+---------------------+---------------------+ 8 | 1 | yql | sunshine | 1 | 28 | 1988-10-20 10:00:00 | NULL 9 | 10 | 2 | Sam | Sam | 0 | 25 | 1989-10-20 10:00:00 | 2005-03-20 10:00:0011 | 12 +----+------+----------+------+------+---------------------+---------------------+
1 插入一条记录： 2 mysql> insert into user (id,name,nikename,sex,age,birth_date) values(1,'yql','sunshine',1,28,'1989-10-20 10:00:00') 3 查看计算结果：to_days(now())天数 4 mysql> select name,(to_days(now())-to_days(birth_date))/365 as age1 from user; 5 +------+---------+ 6 | name | age1 | 7 +------+---------+ 8 | yql | 26.9863 | 9 +------+---------+ 10 1 row in set (0.06 sec)
