SQL增、查、改语句

SQL语句

INSERT INTO table_name (列1, 列2,…) VALUES (值1, 值2,….)
SELECT */列名称 FROM 表名称
UPDATE 表名称 SET 列名称 = 新值 WHERE 列名称 = 某值
DELETE FROM 表名称 WHERE 列名称 = 值

SELECT {COLA,COLB,*} FROM {TABLE}
WHERE {CONDITION}
ORDER BY {COL} DESC
LIMIT {OFF},{COUNT}

数据库更新 SQL语句
update message set content=”数据库更新” where id = “7”;
用count做一个统计
select count(id) from message where conversation_id = “12_14”;
select content from message where conversation_id=”12_14” order by id limit 3 offset 1;

count统计次数，group by分组