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  • SQLyog中创建数据表及相关查询方法

    USE du;
    /*1.创建账务表  id name  mony*/
    CREATE TABLE zhangwu(id INT PRIMARY KEY AUTO_INCREMENT,
                  sname VARCHAR(200),
                  money DOUBLE);
    /*2.插入数据*/
    INSERT INTO zhangwu VALUES(1,'吃饭支出',666);
    INSERT INTO zhangwu VALUES(2,'睡觉支出',666);
    INSERT INTO zhangwu VALUES(3,'打豆豆支出',666);
    INSERT INTO zhangwu VALUES(4,'吃饭支出',666);
    INSERT INTO zhangwu VALUES(5,'吃饭支出',666);
    UPDATE zhangwu SET money=888 WHERE id=2;
    UPDATE zhangwu SET money=766 WHERE id=3;
    /*3.从zhangwu表中选出id   sname   */
    SELECT id FROM zhangwu ;
    SELECT sname FROM zhangwu ;
    /*4.把zhangwu表中的sname去重 */
    SELECT DISTINCT sname FROM zhangwu ;
    /*5.别名  列名查询   使用关键字as*/
        /*查询money列,定义新的列名m*/
    SELECT money AS m FROM zhangwu ;
    SELECT money AS ling FROM zhangwu ;
    /*6.对列进行运算*/
        /*从zhangwu表中挑选sname ,所有money+1000*/
    SELECT sname ,money+1000 FROM zhangwu ;
    /*7.数据条件的查询 where, 格式:select 字段 from 表名 where 条件*/
        /*从zhangwu中挑选出sname为吃饭支出的记录*/
    SELECT * FROM zhangwu WHERE sname='吃饭支出';
        /*从zhangwu中挑选出money大于等于100的记录*/
    SELECT * FROM zhangwu WHERE money>=100;
        /*从zhangwu中挑选出money在600到700之间的记录*/
    SELECT * FROM zhangwu WHERE money BETWEEN 600 AND 700;
    SELECT * FROM zhangwu WHERE money>=600 AND money<700; 
    /*8.模糊查询*/
        /*从zhangwu表中挑选出sname中有支出的记录*/
    SELECT * FROM zhangwu WHERE sname LIKE '%支出%';
        /*从zhangwu表中挑选出sname中有五个字符的记录*/
    SELECT * FROM zhangwu WHERE sname LIKE '_____';/*五个下划线*/
        /*从zhangwu表中挑选出sname中不为空的记录*/
    SELECT * FROM zhangwu WHERE sname IS NOT NULL;
    /*9.排序查询   格式:oderby 列名 asc升序    desc降序*/
    SELECT * FROM zhangwu ORDER BY money ASC;
    SELECT * FROM zhangwu ORDER BY money DESC;
    /*10.聚合函数  count 对表中的数据的个数求和*/
    SELECT COUNT(*) AS '总数' FROM zhangwu ; 
    /*11.IN关键字 ,在zhangwu的money里挑选出66,666,700记录*/
    SELECT * FROM zhangwu WHERE money IN (66,666,700);
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  • 原文地址:https://www.cnblogs.com/duguangming/p/10623694.html
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