SQL的增删改査
1、查询 selecet
语法:SELECT column_name,column_name FROM table_name;
1.1 查询某些列数据 SELECT phone,name FROM leader;
1.2 查询表中所有数据 SELECT * FROM leader;
1.3 查询去重复之后的数据 SELECT DISTINCT column_name,column_name FROM table_name;
1.4 查询条件过滤 SELECT phone,name FROM leader; where parent_id='10000043' where 后面跟运算符 = > < != beteween like in and等
2、修改 update
UPDATE table_name SET column1=value1,column2=value2,...WHERE some_column=some_value;
3、删除 delete
DELETE FROM table_name WHERE some_column=some_value;
4、增加 insert
INSERT INTO table_name VALUES (value1,value2,value3,...);
5、order by
ORDER BY 关键字用于对结果集按照一个列或者多个列进行排序。默认按照升序对记录进行排序。如果需要按照降序对记录进行排序,您可以使用 DESC 关键字
SELECT column_name,column_name
FROM table_name
ORDER BY column_name,column_name ASC|DESC; ASC升序|DESC 降序