mysql常用語句

1.創建表

表是數據庫存儲數據的基本單位。個一個表包含若干字段或記錄；
語法：
CREATE TABLE 表名( 屬性名數據類型[完整性約束條件],
            屬性名數據類型[完整性約束條件],
.
.
屬性名數據表格[完整性約束條件]
);

一、查詢

SELECT id,stuName,age,sex,gradeName FROM t_student ;

SELECT stuName,id,age,sex,gradeName FROM t_student ;

SELECT * FROM t_student;

SELECT stuName,gradeName FROM t_student;

二、where條件查詢

SELECT * FROM t_student WHERE id=1;

SELECT * FROM t_student WHERE age>22;

三、帶in關鍵字查詢

   SELECT * FROM t_student WHERE age IN (21,23);
SELECT * FROM t_student WHERE age NOT IN (21,23);

四、帶between and 關鍵字查詢

SELECT * FROM t_student WHERE age BETWEEN 21 AND 24;
SELECT * FROM t_student WHERE age NOT BETWEEN 21 AND 24;

五、帶like的模糊查詢

SELECT * FROM t_student WHERE stuName LIKE '張三';
SELECT * FROM t_student WHERE stuName LIKE '張三%';
SELECT * FROM t_student WHERE stuName LIKE '張三__';
SELECT * FROM t_student WHERE stuName LIKE '%張三%';只要含有張三的
六、空值查詢

SELECT * FROM t_student WHERE sex IS NULL;
SELECT * FROM t_student WHERE sex IS NOT NULL;
七、帶AND的多條件查詢

  SELECT * FROM t_student WHERE gradeName='一年級' AND age=23
SELECT * FROM t_student WHERE gradeName='一年級' OR age=23
八、帶OR的多條件查詢

九、DISTINCT去重複查詢

SELECT DISTINCT gradeName FROM t_student;
11.對查詢結果排序

SELECT * FROM t_student ORDER BY age ASC;
SELECT * FROM t_student ORDER BY age DESC；降序，默認升序。
12.guoup BY分組查詢

SELECT * FROM t_student GROUP BY gradeName;

SELECT gradeName,GROUP_CONCAT(stuName) FROM t_student GROUP BY gradeName;


SELECT gradeName,COUNT(stuName) FROM t_student GROUP BY gradeName;


SELECT gradeName,COUNT(stuName) FROM t_student GROUP BY gradeName HAVING COUNT(stuName)>3;


SELECT gradeName,COUNT(stuName) FROM t_student GROUP BY gradeName WITH ROLLUP;
SELECT gradeName,GROUP_CONCAT(stuName) FROM t_student GROUP BY gradeName WITH ROLLUP;
13.LIMIT分頁查詢

SELECT * FROM t_student LIMIT 0,5;
SELECT * FROM t_student LIMIT 5,5;
SELECT * FROM t_student LIMIT 10,5;