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MySQL 教程

MySQL 教程 MySQL 简介 MySQL 管理系统

MySQL SQL 语句

MySQL SQL MySQL SELECT MySQL WHERE MySQL AND, OR, NOT MySQL ORDER BY MySQL INSERT INTO MySQL NULL Values MySQL UPDATE MySQL DELETE MySQL LIMIT MySQL MIN 和 MAX MySQL COUNT, AVG, SUM MySQL LIKE MySQL 通配符 MySQL IN MySQL BETWEEN MySQL 别名 MySQL 联接 MySQL INNER JOIN MySQL LEFT JOIN MySQL RIGHT JOIN MySQL CROSS JOIN MySQL 自联接 MySQL UNION MySQL GROUP BY MySQL HAVING MySQL EXISTS MySQL ANY, ALL MySQL INSERT SELECT MySQL CASE MySQL Null 函数 MySQL 注释 MySQL 运算符

MySQL 数据库

MySQL 创建数据库 MySQL 删除数据库 MySQL 创建表 MySQL 删除表 MySQL 更改表 MySQL 约束 MySQL Not Null MySQL Unique MySQL Primary Key MySQL Foreign Key MySQL Check MySQL Default MySQL Create Index MySQL 自动增量 MySQL 日期 MySQL 视图

MySQL 参考手册

MySQL 数据类型 MySQL 函数
String 字符串函数 ASCII CHAR_LENGTH CHARACTER_LENGTH CONCAT CONCAT_WS FIELD FIND_IN_SET FORMAT INSERT INSTR LCASE LEFT LENGTH LOCATE LOWER LPAD LTRIM MID POSITION REPEAT REPLACE REVERSE RIGHT RPAD RTRIM SPACE STRCMP SUBSTR SUBSTRING SUBSTRING_INDEX TRIM UCASE UPPER Numeric 数值函数 ABS ACOS ASIN ATAN ATAN2 AVG CEIL CEILING COS COT COUNT DEGREES DIV EXP FLOOR GREATEST LEAST LN LOG LOG10 LOG2 MAX MIN MOD PI POW POWER RADIANS RAND ROUND SIGN SIN SQRT SUM TAN TRUNCATE Date 日期函数 ADDDATE ADDTIME CURDATE CURRENT_DATE CURRENT_TIME CURRENT_TIMESTAMP CURTIME DATE DATEDIFF DATE_ADD DATE_FORMAT DATE_SUB DAY DAYNAME DAYOFMONTH DAYOFWEEK DAYOFYEAR EXTRACT FROM_DAYS HOUR LAST_DAY LOCALTIME LOCALTIMESTAMP MAKEDATE MAKETIME MICROSECOND MINUTE MONTH MONTHNAME NOW PERIOD_ADD PERIOD_DIFF QUARTER SECOND SEC_TO_TIME STR_TO_DATE SUBDATE SUBTIME SYSDATE TIME TIME_FORMAT TIME_TO_SEC TIMEDIFF TIMESTAMP TO_DAYS WEEK WEEKDAY WEEKOFYEAR YEAR YEARWEEK 高级功能 BIN BINARY CASE CAST COALESCE CONNECTION_ID CONV CONVERT CURRENT_USER DATABASE IF IFNULL ISNULL LAST_INSERT_ID NULLIF SESSION_USER SYSTEM_USER USER VERSION

MySQL 实例

MySQL 实例 MySQL 测验 MySQL 练习

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MySQL HAVING 子句

MySQL HAVING 子句

HAVING 子句已添加到 SQL，因为 WHERE 关键字不能与聚合函数一起使用。

HAVING 语法

SELECT column_name(s)
FROM table_name
WHERE condition
GROUP BY column_name(s)
HAVING condition
ORDER BY column_name(s);

演示数据库

以下是 Northwind 示例数据库中"Customers"表的选择:

CustomerID CustomerName ContactName Address City PostalCode Country
1

 Alfreds Futterkiste Maria Anders Obere Str. 57 Berlin 12209 Germany
2 Ana Trujillo Emparedados y helados Ana Trujillo Avda. de la Constitución 2222 México D.F. 05021 Mexico
3 Antonio Moreno Taquería Antonio Moreno Mataderos 2312 México D.F. 05023 Mexico
4

 Around the Horn Thomas Hardy 120 Hanover Sq. London WA1 1DP UK
5 Berglunds snabbköp Christina Berglund Berguvsvägen 8 Luleå S-958 22 Sweden

MySQL HAVING 示例

以下 SQL 语句列出了每个地区的客户数量。 仅包括拥有 5 个以上客户的地区:

实例

SELECT COUNT(CustomerID), Country
FROM Customers
GROUP BY Country
HAVING COUNT(CustomerID) > 5;
亲自试一试 »

以下 SQL 语句列出了每个地区的客户数量，从高到低排序（仅包括客户超过 5 个的地区）:

实例

SELECT COUNT(CustomerID), Country
FROM Customers
GROUP BY Country
HAVING COUNT(CustomerID) > 5
ORDER BY COUNT(CustomerID) DESC;
亲自试一试 »

演示数据库

以下是 Northwind 示例数据库中"Orders"表的选择:

OrderID CustomerID EmployeeID OrderDate ShipperID
10248 90 5 1996-07-04 3
10249 81 6 1996-07-05 1
10250 34 4 1996-07-08 2

以及从"Employees"表中选择的内容:

EmployeeID LastName FirstName BirthDate Photo Notes
1 Davolio Nancy 1968-12-08 EmpID1.pic Education includes a BA....
2 Fuller Andrew 1952-02-19 EmpID2.pic Andrew received his BTS....
3 Leverling Janet 1963-08-30 EmpID3.pic Janet has a BS degree....

更多 HAVING 示例

以下 SQL 语句列出了注册超过 10 个订单的员工:

实例

SELECT Employees.LastName, COUNT(Orders.OrderID) AS NumberOfOrders
FROM (Orders
INNER JOIN Employees ON Orders.EmployeeID = Employees.EmployeeID)
GROUP BY LastName
HAVING COUNT(Orders.OrderID) > 10;
亲自试一试 »

以下 SQL 语句列出员工"Davolio"或"Fuller"是否已注册超过 25 个订单:

实例

SELECT Employees.LastName, COUNT(Orders.OrderID) AS NumberOfOrders
FROM Orders
INNER JOIN Employees ON Orders.EmployeeID = Employees.EmployeeID
WHERE LastName = 'Davolio' OR LastName = 'Fuller'
GROUP BY LastName
HAVING COUNT(Orders.OrderID) > 25;
亲自试一试 »

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