2016-6-7

插入记录：

INSERT  [INTO] table_name (column_name,...) VALUES();可以插入多条记录

INSERT table_name SET column_name =  只能插入一条记录

INSERT table_name SELECT column_name FROM table_name [LIMIT];插入另一张表中的数据

更新记录

UPDATE table_name SET column_name = {exp|default},... [WHERE where_condition]

删除记录

DELETE FROM table_name WHERE where_condition 

SELECT语句

SELECT {expr}e.g. SELECT 3+5;

SELECT column_name1,column_name2,... FROM table_name显示顺序与SELECT语句输入顺序有关

SELECT column_name AS alias_name起别名（AS可省略 但不推荐）

分组查询

SELECT column_name FROM table_name GROUP BY column_name [ASC|DESC];

分组的条件HAVING 分组过滤条件：HAVING 后的字段必须是SELECT后出现过的或为聚合函数COUNT：计算行的数量，MAX：计算列的最大值，MIN：计算列的最小值，SUM：获取单个列的合计值，AVG：计算某个列的平均值等）中

排序操作

ORDER BY column_name [ASC|DESC],column_name [ASC|DESC];

限制查找数量

LIMIT {[offset,] row_count | row_count OFFSET offset}]php分页技术会用到

SELECT 常用总结

SELECT {select_expr [,select_expr,...]

{

FROM table_name

[WHERE where_condition]

[GROUP BY {col_name | position} [ASC | DESC],...]

[HAVING condition]

[ORDER BY column_name [ASC | DESC]

[LIMIT {[offset,] row_count | [row_count OFFSET offset]}

}