MySQL 8 教程

MySQL 主页 MySQL 简介 MySQL 功能 MySQL 版本 MySQL 变量 MySQL 下载安装和环境配置 MySQL 管理 MySQL PHP 语法 MySQL Node.js 语法 MySQL Java 语法 MySQL Python 语法 MySQL 连接 MySQL Workbench

MySQL 8 数据库

MySQL 创建数据库 MySQL 删除数据库 MySQL 选择数据库 MySQL 显示数据库 MySQL 复制数据库 MySQL 数据库导出 MySQL 数据库导入 MySQL 数据库信息

MySQL 8 用户

MySQL 创建用户 MySQL 删除用户 MySQL 显示用户 MySQL 更改密码 MySQL 授予权限 MySQL 显示权限 MySQL 撤销权限 MySQL 锁定用户账户 MySQL 解锁用户账户

MySQL 8 表

MySQL 创建表 MySQL 显示表 MySQL 修改表 MySQL 重命名表 MySQL 克隆表 MySQL 截断表 MySQL 临时表 MySQL 修复表 MySQL 描述表 MySQL 添加/删除列 MySQL 显示列 MySQL 重命名列 MySQL 表锁定 MySQL 删除表 MySQL 派生表

MySQL 8 查询

MySQL 查询 MySQL 约束 MySQL INSERT 插入查询 MySQL SELECT 查询 MySQL UPDATE 更新查询 MySQL DELETE删除查询 MySQL REPLACE 替换查询 MySQL 忽略插入 MySQL 重复键更新时插入 MySQL 插入到另一个表语句

MySQL 8 视图

MySQL 创建视图 MySQL 更新视图 MySQL 删除视图 MySQL 重命名视图

MySQL 8 索引

MySQL 索引 MySQL 创建索引 MySQL 删除索引 MySQL 显示索引 MySQL 唯一索引 MySQL 聚集索引 MySQL 非聚集索引

MySQL 运算符和子句

MySQL Where 子句 MySQL Limit 子句 MySQL Distinct 子句 MySQL Order By 子句 MySQL Group By 子句 MySQL Having 子句 MySQL AND 运算符 MySQL OR 或运算符 MySQL LIKE 运算符 MySQL IN 运算符 MySQL ANY 运算符 MySQL Exists 运算符 MySQL NOT 运算符 MySQL NOT EQUAL 运算符 MySQL IS NULL 运算符 MySQL IS NOT NULL 运算符 MySQL Between 运算符 MySQL UNION 运算符 MySQL UNION 与 UNION ALL MySQL MINUS 运算符 MySQL INTERSECT 运算符 MySQL INTERVAL 运算符

MySQL 连接

MySQL 使用连接 MySQL Inner Join 内连接 MySQL LEFT JOIN 左连接 MySQL RIGHT JOIN 右连接 MySQL CROSS JOIN 交叉连接 MySQL 全连接 MySQL 自连接 MySQL Delete Join 删除连接 MySQL UPDATE JOIN 更新连接 MySQL 联合 vs 连接

MySQL 键

MySQL UNIQUE 唯一键 MySQL PRIMARY KEY 主键 MySQL FOREIGN KEY 外键 MySQL 复合键 MySQL 备用键

MySQL 触发器

MySQL 触发器 MySQL 创建触发器 MySQL 显示触发器 MySQL 删除触发器 MySQL 插入前触发器 MySQL 插入后触发器 MySQL 更新前触发器 MySQL 更新后触发器 MySQL 删除前触发器 MySQL 删除后触发器

MySQL 8 数据类型

MySQL 数据类型 MySQL VARCHAR MySQL BOOLEAN MySQL ENUM 枚举 MySQL DECIMAL 十进制 MySQL INT 整数 MySQL FLOAT 浮点数 MySQL BIT 位 MySQL TINYINT 微小整数 MySQL BLOB 二进制大对象 MySQL SET 集合

MySQL 正则表达式

MySQL 正则表达式 MySQL RLIKE 运算符 MySQL NOT LIKE 运算符 MySQL NOT REGEXP 运算符 MySQL regexp_instr() 函数 MySQL regexp_like() 函数 MySQL regexp_replace() 函数 MySQL regexp_substr() 函数

MySQL 全文搜索

MySQL 全文搜索 MySQL 自然语言全文搜索 MySQL 布尔全文搜索 MySQL 查询扩展全文搜索 MySQL ngram 全文解析器

MySQL8 函数和运算符

MySQL 日期和时间函数 MySQL 算术运算符 MySQL 数字函数 MySQL 字符串函数 MySQL 聚合函数

MySQL 8 其他概念

MySQL NULL 值 MySQL 事务 MySQL 序列 MySQL 处理重复项 MySQL SQL 注入 MySQL 子查询 MySQL 注释 MySQL 检查约束 MySQL 存储引擎 MySQL 将表导出为 CSV 文件 MySQL 将 CSV 文件导入数据库 MySQL UUID MySQL 通用表表达式 MySQL 级联删除 MySQL Upsert 操作 MySQL 水平分区 MySQL 垂直分区 MySQL 游标 MySQL 存储函数 MySQL SIGNAL 异常处理 MySQL RESIGNAL 异常处理 MySQL 字符集 MySQL 排序规则 MySQL 通配符 MySQL 别名 MySQL ROLLUP 超级聚合 MySQL 当前日期 MySQL 字面量 MySQL 存储过程 MySQL EXPLAIN 语句 MySQL JSON MySQL 标准差 MySQL 查找重复记录 MySQL 删除重复记录 MySQL 选择随机记录 MySQL 显示进程列表 MySQL 更改列类型 MySQL 重置自动增量 MySQL Coalesce() 函数

MySQL 8 实用资源

MySQL 实用函数 MySQL 语句参考 MySQL 快速指南 MySQL 实用资源 MySQL 讨论


MySQL - ROLLUP

MySQL ROLLUP 子句

MySQL ROLLUP 子句是 GROUP BY 子句的扩展。它与 MySQL 中的聚合函数一起使用,用于在表中的额外行中查找列值的总计或汇总(也称为列的超级聚合)。

假设有一家制造工厂,它在表中跟踪月度生产数据。要确定年度产品产量,您可以将 SUM() 聚合函数与 ROLLUP 结合使用。但是,如果您需要找出产量低于特定阈值的月份数,ROLLUP 还允许您使用 COUNT() 函数来统计这些月份。

语法

以下是 MySQL 中 ROLLUP 子句的语法 -

SELECT AggregateFunction(column_name(s)), column_name(s)
FROM table_name
GROUP BY column_name(s)
WITH ROLLUP;

示例

首先,我们将创建一个名为"PRODUCT"的表,其中包含组织内的生产信息,例如产品 ID、产品名称、产品数量和生产月份 -

CREATE TABLE PRODUCT (
   PRODUCT_ID INT,
   PRODUCT_NAME VARCHAR(50),
   PRODUCT_COUNT INT,
   MONTH VARCHAR(20)
);

现在,让我们向上面创建的表中插入一些数据 -

INSERT INTO PRODUCT VALUES
(101, 'Comb', 2345, 'January'),
(102, 'Coffee Mugs', 1242, 'January'),
(103, 'Cutlery', 124, 'January'),
(101, 'Comb', 3263, 'February'),
(102, 'Coffee Mugs', 10982, 'February'),
(103, 'Cutlery', 435, 'February');

获得的PRODUCT表如下-

PRODUCT_ID PRODUCT_NAME PRODUCT_COUNT MONTH
101 Comb 2345 January
102 Coffee Mugs 1242 January
103 Cutlery 124 January
101 Comb 3263 February
102 Coffee Mugs 10982 February
103 Cutlery 435 February

现在,让我们使用 ROLLUP 函数计算每个月生产的产品总数,如下所示 -

SELECT SUM(PRODUCT_COUNT), MONTH
FROM PRODUCT
GROUP BY MONTH WITH ROLLUP;

输出

您可以在下面的输出中看到,一月和二月的单个产品数量均已计算,并且使用 ROLLUP 函数在第三行显示了总产量的总计 -

SUM(PRODUCT_COUNT) MONTH
14680 February
3711 January
18391 NULL

对多列执行 ROLLUP 操作

您还可以使用 GROUP BY 子句对多列进行分组,从而实现 ROLLUP 操作。

示例

此处,我们将 GROUP BY 子句应用于 PRODUCT 表的"PRODUCT_ID"和"PRODUCT_NAME"列 -

SELECT PRODUCT_ID,
COUNT(PRODUCT_ID) AS PROD_ID_COUNT,
PRODUCT_NAME,
COUNT(PRODUCT_NAME) AS PROD_ID_NAME
FROM PRODUCT
GROUP BY PRODUCT_ID, PRODUCT_NAME;

我们得到以下输出 -

PRODUCT_ID PROD_ID_COUNT PRODUCT_NAME PROD_ID_NAME
101 2 Comb 2
102 2 Coffee Mugs 2
103 2 Cutlery 2

现在,使用 ROLLUP 计算这两行的汇总,如下查询所示 -

SELECT PRODUCT_ID,
COUNT(PRODUCT_ID) AS PROD_ID_COUNT,
PRODUCT_NAME,
COUNT(PRODUCT_NAME) AS PROD_ID_NAME
FROM PRODUCT
GROUP BY PRODUCT_ID, PRODUCT_NAME
WITH ROLLUP;

您可以在下面的输出中看到,汇总不仅在最后一级计算,而且在两级计算。对于每个产品名称,都会显示一列汇总 -

PRODUCT_ID PROD_ID_COUNT PRODUCT_NAME PROD_ID_NAME
101 2 Comb 2
101 2 NULL 2
102 2 Coffee Mugs 2
102 2 NULL 2
103 2 Cutlery 2
103 2 NULL 2
NULL 6 NULL 6

使用客户端程序进行汇总

我们也可以使用客户端程序进行汇总。

语法

要通过 PHP 程序使用带有聚合函数的 ROLLUP 计算某一列的总计,我们需要使用 mysqli 函数 query() 执行"SELECT"语句,如下所示 -

$sql = "SELECT SUM(PRODUCT_COUNT), MONTH FROM PRODUCT GROUP BY MONTH WITH ROLLUP";
$mysqli->query($sql);

要通过 JavaScript 程序使用带有聚合函数的 ROLLUP 计算某一列的总计,我们需要使用 mysql2 库的 query() 函数执行"SELECT"语句,如下所示 -

sql = "SELECT SUM(PRODUCT_COUNT), MONTH FROM PRODUCT GROUP BY MONTH WITH ROLLUP";
con.query(sql);

要通过 Java 程序使用带有聚合函数的 ROLLUP 计算某一列的总计,我们需要使用 JDBC 函数 executeQuery() 执行"SELECT"语句,如下所示 -

String sql = "SELECT SUM(PRODUCT_COUNT), MONTH FROM PRODUCT GROUP BY MONTH WITH ROLLUP";
statement.executeQuery(sql);

要通过 Python 程序使用带有聚合函数的 ROLLUP 计算某一列的总计,我们需要使用 MySQL Connector/Python 的 execute() 函数执行"SELECT"语句,如下所示 -

rollup_query = "SELECT SUM(PRODUCT_COUNT), MONTH FROM PRODUCT GROUP BY MONTH WITH ROLLUP"
cursorObj.execute(rollup_query)

示例

以下是程序 -

$dbhost = 'localhost';
$dbuser = 'root';
$dbpass = 'password';
$db = 'TUTORIALS';
$mysqli = new mysqli($dbhost, $dbuser, $dbpass, $db);
if ($mysqli->connect_errno) {
    printf("Connect failed: %s
", $mysqli->connect_error); exit(); } //printf('Connected successfully.
'); $sql = "CREATE TABLE PRODUCT ( PRODUCT_ID INT, PRODUCT_NAME VARCHAR(50), PRODUCT_COUNT INT, MONTH VARCHAR(20) )"; if($mysqli->query($sql)){ printf("Product table created successfully....!"); } //now let's insert some records into the table $sql = "INSERT INTO PRODUCT VALUES(101, 'Comb', 2345, 'January')"; if($mysqli->query($sql)){ printf("First record inserted successfully...! "); } $sql = "INSERT INTO PRODUCT VALUES(102, 'Coffee Mugs', 1242, 'January')"; if($mysqli->query($sql)){ printf("Second record inserted successfully...! "); } $sql = "INSERT INTO PRODUCT VALUES(103, 'Cutlery', 124, 'January')"; if($mysqli->query($sql)){ printf("Third record inserted successfully...! "); } $sql = "INSERT INTO PRODUCT VALUES(101, 'Comb', 3263, 'February')"; if($mysqli->query($sql)){ printf("Fourth record inserted successfully...! "); } //display the table records $sql = "SELECT * FROM PRODUCT"; if($result = $mysqli->query($sql)){ printf("Table records: "); while($row = mysqli_fetch_array($result)){ printf("PRODUCT_ID: %d, PRODUCT_NAME: %s, PRODUCT_COUNT: %d, MONTH: %s", $row['PRODUCT_ID'], $row['PRODUCT_NAME'], $row['PRODUCT_COUNT'], $row['MONTH']); printf(" "); }} //let's find the sum of product $sql = "SELECT SUM(PRODUCT_COUNT), MONTH FROM PRODUCT GROUP BY MONTH WITH ROLLUP"; if($result = $mysqli->query($sql)){ printf("Sum of product: "); while($row = mysqli_fetch_array($result)){ printf("Sum of product: %d, MONTH: %s", $row['SUM(PRODUCT_COUNT)'], $row['MONTH']); printf(" "); } } if($mysqli->error){ printf("Error message: ", $mysqli->error); } $mysqli->close();

输出

获得的输出如下所示 -

Product table created successfully....!
First record inserted successfully...!
Second record inserted successfully...!
Third record inserted successfully...!
Fourth record inserted successfully...!
Table records: 
PRODUCT_ID: 101, PRODUCT_NAME: Comb, PRODUCT_COUNT: 2345, MONTH: January
PRODUCT_ID: 102, PRODUCT_NAME: Coffee Mugs, PRODUCT_COUNT: 1242, MONTH: January
PRODUCT_ID: 103, PRODUCT_NAME: Cutlery, PRODUCT_COUNT: 124, MONTH: January
PRODUCT_ID: 101, PRODUCT_NAME: Comb, PRODUCT_COUNT: 3263, MONTH: February
Sum of product:
Sum of product: 3263, MONTH: February
Sum of product: 3711, MONTH: January
Sum of product: 6974, MONTH:       

var mysql = require('mysql2');
var con = mysql.createConnection({
    host: "localhost",
    user: "root",
    password: "Nr5a0204@123"
});

// Connecting to MySQL
con.connect(function (err) {
    if (err) throw err;
    console.log("Connected!");
    console.log("--------------------------");
   // Create a new database
    sql = "Create Database TUTORIALS";
    con.query(sql);
   sql = "USE TUTORIALS";
    con.query(sql);
   sql = "CREATE TABLE PRODUCT (PRODUCT_ID INT,PRODUCT_NAME VARCHAR(50),PRODUCT_COUNT INT,MONTH VARCHAR(20));"
    con.query(sql);
   sql = "INSERT INTO PRODUCT VALUES(101, 'Comb', 2345, 'January'),(102, 'Coffee Mugs', 1242, 'January'),(103, 'Cutlery', 124, 'January'),(101, 'Comb', 3263, 'February'),(102, 'Coffee Mugs', 10982, 'February'),(103, 'Cutlery', 435, 'February');"
    con.query(sql);
   sql = "SELECT SUM(PRODUCT_COUNT), MONTH FROM PRODUCT GROUP BY MONTH WITH ROLLUP";
    con.query(sql, function(err, result){
      if (err) throw err
      console.log(result);
    });
}); 

输出

获得的输出如下所示 -

Connected!
--------------------------
[
  { 'SUM(PRODUCT_COUNT)': '14680', MONTH: 'February' },
  { 'SUM(PRODUCT_COUNT)': '3711', MONTH: 'January' },
  { 'SUM(PRODUCT_COUNT)': '18391', MONTH: null }
]   
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
public class RollUp {
    public static void main(String[] args) {
        String url = "jdbc:mysql://localhost:3306/TUTORIALS";
        String user = "root";
        String password = "password";
        ResultSet rs;
        try {
            Class.forName("com.mysql.cj.jdbc.Driver");
            Connection con = DriverManager.getConnection(url, user, password);
            Statement st = con.createStatement();
            //System.out.println("Database connected successfully...!");
            //create a table with name Product
            String sql = "CREATE TABLE PRODUCT ( PRODUCT_ID INT, PRODUCT_NAME VARCHAR(50), PRODUCT_COUNT INT, MONTH VARCHAR(20) )";
            st.execute(sql);
            System.out.println("Product table created successfully....!");
            //let's insert some records into it...
            String sql1 = "INSERT INTO PRODUCT VALUES(101, 'Comb', 2345, 'January'),  (102, 'Coffee Mugs', 1242, 'January'), (103, 'Cutlery', 124, 'January'), (101, 'Comb', 3263, 'February')";
            st.execute(sql1);
            System.out.println("Records inserted successfully...!");
            //print table records
            String sql2 = "SELECT * FROM PRODUCT";
            rs = st.executeQuery(sql2);
            System.out.println("Table records: ");
            while(rs.next()) {
                String PRODUCT_ID = rs.getString("PRODUCT_ID");
                String PRODUCT_NAME = rs.getString("PRODUCT_NAME");
                String PRODUCT_COUNT = rs.getString("PRODUCT_COUNT");
                String MONTH = rs.getString("MONTH");
                System.out.println("PRODUCT_ID: " + PRODUCT_ID + ", PRODUCT_NAME: " + PRODUCT_NAME + ", PRODUCT_COUNT: " + PRODUCT_COUNT + ", MONTH: " + MONTH);
            }
            //let's calculate the sum of product with RollUp
            String sql3 = "SELECT SUM(PRODUCT_COUNT), MONTH FROM PRODUCT GROUP BY MONTH WITH ROLLUP";
            rs = st.executeQuery(sql3);
            System.out.println("Sum of product: ");
            while(rs.next()) {
                String sum = rs.getString("SUM(PRODUCT_COUNT)");
                String MONTH = rs.getString("MONTH");
                System.out.println("Sum: " + sum + ", MONTH: " + MONTH);
            }
        }catch(Exception e) {
            e.printStackTrace();
        }
    }
}    

输出

获得的输出如下所示 -

Product table created successfully....!
Records inserted successfully...!
Table records: 
PRODUCT_ID: 101, PRODUCT_NAME: Comb, PRODUCT_COUNT: 2345, MONTH: January
PRODUCT_ID: 102, PRODUCT_NAME: Coffee Mugs, PRODUCT_COUNT: 1242, MONTH: January
PRODUCT_ID: 103, PRODUCT_NAME: Cutlery, PRODUCT_COUNT: 124, MONTH: January
PRODUCT_ID: 101, PRODUCT_NAME: Comb, PRODUCT_COUNT: 3263, MONTH: February
Sum of product: 
Sum: 3263, MONTH: February
Sum: 3711, MONTH: January
Sum: 6974, MONTH: null
import mysql.connector
# 建立连接
connection = mysql.connector.connect(
    host='localhost',
    user='root',
    password='password',
    database='tut'
)
# 创建游标对象
cursorObj = connection.cursor()
# 提供汇总查询
rollup_query = """SELECT SUM(PRODUCT_COUNT), MONTH FROM PRODUCT GROUP BY MONTH WITH ROLLUP"""
cursorObj.execute(rollup_query)
# 获取并打印结果
results = cursorObj.fetchall()
print("Rollup Results:")
for row in results:
    print(f"Product Count: {row[0]}, MONTH: {row[1]}")
# 关闭游标和连接
cursorObj.close()
connection.close()      

输出

获得的输出如下所示 -

Rollup Results:
Product Count: 14680, MONTH: February
Product Count: 3711, MONTH: January
Product Count: 18391, MONTH: None