ResultSet 的 updateRow() 方法示例
jdbcjava 8object oriented programmingprogramming更新于 2025/6/23 3:24:17
当我们执行某些 SQL 查询(通常是 SELECT 查询)时，它们会返回表格数据。
java.sql.ResultSet 接口表示由 SQL 语句返回的表格数据。
也就是说，ResultSet 对象保存由执行查询数据库的语句的方法(通常是 Statement 接口的 executeQuery() 方法)返回的表格数据。
ResultSet 对象有一个指向当前行的游标/指针。最初，此游标位于第一行之前。
ResultSet 接口的 updateRow() 方法将当前行的内容更新到数据库中。例如，如果我们使用 ResultSet 接口的 updateXXX() 方法(updateNClob()、updateNCharacterStream()、updateString()、updateInt()、updateNString() 和 updateBinaryStream())更新了特定记录的值。
您需要调用此方法来反映您对数据库中该行所做的更改。
注意:要使用 updateRow() 方法更新 ResultSet 的内容，ResultSet 的类型应为 CONCUR_UPDATABLE，并且表应包含主键约束。
让我们使用 CREATE 语句在 MySQL 数据库中创建一个名为"customers"的表，如下所示:
CREATE TABLE customers ( ID INT, Name VARCHAR(20), AGE INT, SALARY INT, ADDERSS VARCHAR(255), PRIMARY KEY (ID) );
Now, we will insert 12 records in customers table using INSERT statements -
insert into customers values(1, 'Amit', 25, 3000, 'Hyderabad'); insert into customers values(2, 'Kalyan', 27, 4000, 'Vishakhapatnam'); insert into customers values(3, 'Renuka', 30, 5000, 'Delhi'); insert into customers values(4, 'Archana', 24, 1500, 'Mumbai'); insert into customers values(5, 'Kaushik', 30, 9000, 'Kota'); insert into customers values(6, 'Hardik', 45, 6400, 'Bhopal'); insert into customers values(7, 'Trupthi', 33, 4360, 'Ahmedabad'); insert into customers values(8, 'Mithili', 26, 4100, 'Vijayawada'); insert into customers values(9, 'Maneesh', 39, 4000, 'Hyderabad'); insert into customers values(10, 'Rajaneesh', 30, 6400, 'Delhi'); insert into customers values(11, 'Komal', 29, 8000, 'Ahmedabad'); insert into customers values(12, 'Manyata', 25, 5000, 'Vijayawada');
以下 JDBC 程序与数据库建立连接，将客户表的内容检索到 ResultSet 对象中，使用 updateXXX() 方法更新 id 值为 5 的行的内容，并使用 updateRow() 方法将整行更新到数据库中。
示例
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class ResultSet_updateRow {
public static void main(String args[]) throws SQLException {
//注册驱动程序
DriverManager.registerDriver(new com.mysql.jdbc.Driver());
//获取连接
String mysqlUrl = "jdbc:mysql://localhost/mydatabase";
Connection con = DriverManager.getConnection(mysqlUrl, "root", "password");
System.out.println("连接已建立......");
//创建语句
Statement stmt = con.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_UPDATABLE);
//查询以检索记录
String query = "Select * from Customers";
//执行查询
ResultSet rs = stmt.executeQuery(query);
//更新 id 值为 5 的记录的内容
while(rs.next()) {
if(rs.getInt(&"ID")==5) {
//更新工资
rs.updateInt(&"Salary", 11000);
//更新地址
rs.updateString(&"ADDRESS",&"Narsipatnam");
//更新行
rs.updateRow();
}
}
rs.beforeFirst();
System.out.println("Contents of the Customers table after the update: ");
//打印表格内容
while(rs.next()) {
System.out.print("ID: "+rs.getInt("ID")+", ");
System.out.print("Name: "+rs.getString("Name")+", ");
System.out.print("Age: "+rs.getInt("Age")+", ");
System.out.print("Salary: "+rs.getInt("Salary")+", ");
System.out.print("Address: "+rs.getString("Address"));
System.out.println();
}
}
}
输出
连接已建立...... Contents of the table Customers: ID: 1, Name: Amit, Age: 25, Salary: 3000, Address: Hyderabad ID: 2, Name: Kalyan, Age: 27, Salary: 4000, Address: Vishakhapatnam ID: 3, Name: Renuka, Age: 30, Salary: 5000, Address: Delhi ID: 4, Name: Archana, Age: 24, Salary: 1500, Address: Mumbai ID: 5, Name: Koushik, Age: 30, Salary: 11000, Address: Narsipatnam ID: 6, Name: Hardik, Age: 45, Salary: 6400, Address: Bhopal ID: 7, Name: Trupthi, Age: 33, Salary: 4360, Address: Ahmedabad ID: 8, Name: Mithili, Age: 26, Salary: 4100, Address: Vijayawada ID: 9, Name: Maneesh, Age: 39, Salary: 4000, Address: Hyderabad ID: 10, Name: Rajaneesh, Age: 30, Salary: 6400, Address: Delhi ID: 11, Name: Komal, Age: 29, Salary: 8000, Address: Ahmedabad ID: 12, Name: Manyata, Age: 25, Salary: 5000, Address: Vijayawada
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