USE du; /*1.創建賬務表 id name mony*/ CREATE TABLE zhangwu(id INT PRIMARY KEY AUTO_INCREMENT, sname VARCHAR(200), money DOUBLE); /*2.插入數據*/ INSERT INTO zhangwu VALUES(1,'吃飯支出',666); INSERT INTO zhangwu VALUES(2,'睡覺支出',666); INSERT INTO zhangwu VALUES(3,'打豆豆支出',666); INSERT INTO zhangwu VALUES(4,'吃飯支出',666); INSERT INTO zhangwu VALUES(5,'吃飯支出',666); UPDATE zhangwu SET money=888 WHERE id=2; UPDATE zhangwu SET money=766 WHERE id=3; /*3.從zhangwu表中選出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.別名 列名查詢 使用關鍵字as*/ /*查詢money列,定義新的列名m*/ SELECT money AS m FROM zhangwu ; SELECT money AS ling FROM zhangwu ; /*6.對列進行運算*/ /*從zhangwu表中挑選sname ，所有money+1000*/ SELECT sname ,money+1000 FROM zhangwu ; /*7.數據條件的查詢 where， 格式：select 字段 from 表名 where 條件*/ /*從zhangwu中挑選出sname為吃飯支出的記錄*/ SELECT * FROM zhangwu WHERE sname='吃飯支出'; /*從zhangwu中挑選出money大於等於100的記錄*/ SELECT * FROM zhangwu WHERE money>=100; /*從zhangwu中挑選出money在600到700之間的記錄*/ SELECT * FROM zhangwu WHERE money BETWEEN 600 AND 700; SELECT * FROM zhangwu WHERE money>=600 AND money<700; /*8.模糊查詢*/ /*從zhangwu表中挑選出sname中有支出的記錄*/ SELECT * FROM zhangwu WHERE sname LIKE '%支出%'; /*從zhangwu表中挑選出sname中有五個字符的記錄*/ SELECT * FROM zhangwu WHERE sname LIKE '_____';/*五個下划線*/
/*從zhangwu表中挑選出sname中不為空的記錄*/ SELECT * FROM zhangwu WHERE sname IS NOT NULL; /*9.排序查詢 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.聚合函數 count 對表中的數據的個數求和*/ SELECT COUNT(*) AS '總數' FROM zhangwu ; /*11.IN關鍵字 ，在zhangwu的money里挑選出66,666，700記錄*/ SELECT * FROM zhangwu WHERE money IN (66,666,700);
