如题所述
假如产品表为 tb ，表中有产品编号字段， 销售表为 tb2有销售数量字段，他们通过产品id关联
如果是求所有销售数量的总和
select tb.产品编号，svm(销售数量) as 总销售数量
from the inner join tb2 on tb.产品id=tb2.产品id
如果是求所有销售数量的总和
select tb.产品编号，svm(销售数量) as 总销售数量
from the inner join tb2 on tb.产品id=tb2.产品id
温馨提示：答案为网友推荐，仅供参考
第1个回答 2019-01-02
package com;
import java.sql.*;
public class MysqlJdbc {
public static void main(String args[]) {
try {
Class.forName("com.mysql.jdbc.Driver"); //加载MYSQL JDBC驱动程序
System.out.println("Success loading Mysql Driver!");
}
catch (Exception e) {
System.out.print("Error loading Mysql Driver!");
e.printStackTrace();
}
try {
Connection connect = DriverManager.getConnection(
"jdbc:mysql://localhost:3306/sakila","root","123");
//连接URL为 jdbc:mysql//服务器地址/数据库名
//后面的2个参数分别是登陆和密码
System.out.println("Success connect Mysql server!");
Statement stmt = connect.createStatement();
ResultSet rs = stmt.executeQuery("select * from actor");
while (rs.next()) {
System.out.println(rs.getString("actor_id")+"\t"+rs.getString("first_name")+"\t"+"\t"+rs.getString("last_name")+"\t"+rs.getString("last_update"));
}
}
catch (Exception e) {
System.out.print("get data error!");
e.printStackTrace();
}
}
}本回答被网友采纳
import java.sql.*;
public class MysqlJdbc {
public static void main(String args[]) {
try {
Class.forName("com.mysql.jdbc.Driver"); //加载MYSQL JDBC驱动程序
System.out.println("Success loading Mysql Driver!");
}
catch (Exception e) {
System.out.print("Error loading Mysql Driver!");
e.printStackTrace();
}
try {
Connection connect = DriverManager.getConnection(
"jdbc:mysql://localhost:3306/sakila","root","123");
//连接URL为 jdbc:mysql//服务器地址/数据库名
//后面的2个参数分别是登陆和密码
System.out.println("Success connect Mysql server!");
Statement stmt = connect.createStatement();
ResultSet rs = stmt.executeQuery("select * from actor");
while (rs.next()) {
System.out.println(rs.getString("actor_id")+"\t"+rs.getString("first_name")+"\t"+"\t"+rs.getString("last_name")+"\t"+rs.getString("last_update"));
}
}
catch (Exception e) {
System.out.print("get data error!");
e.printStackTrace();
}
}
}本回答被网友采纳
