以下是使用Result Set教程中描述的ResultSet.CONCUR_UPDATABLE和ResultSet.TYPE_SCROLL_INSENSITIVE示例。本示例將說明對表的INSERT，UPDATE和DELETE操作。
應(yīng)該注意的是，您正在處理的表應(yīng)正確設(shè)置主鍵。
該示例代碼是根據(jù)前幾章中的環(huán)境和數(shù)據(jù)庫設(shè)置編寫的。
復制并粘貼以下示例到JDBCExample.java中，如下編譯并運行：
//步驟1.導入所需的軟件包
import java.sql.*;
public class JDBCExample {
// JDBC驅(qū)動程序名稱和數(shù)據(jù)庫URL
static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";
static final String DB_URL = "jdbc:mysql://localhost/EMP";
// 數(shù)據(jù)庫憑證
static final String USER = "username";
static final String PASS = "password";
public static void main(String[] args) {
Connection conn = null;
try{
//步驟2：注冊JDBC驅(qū)動程序
Class.forName("com.mysql.jdbc.Driver");
//步驟3：建立連接
System.out.println("Connecting to database...");
conn = DriverManager.getConnection(DB_URL,USER,PASS);
//步驟4：執(zhí)行查詢以創(chuàng)建陳述
// RS示例的必需參數(shù)。
System.out.println("Creating statement...");
Statement stmt = conn.createStatement(
ResultSet.TYPE_SCROLL_INSENSITIVE,
ResultSet.CONCUR_UPDATABLE);
//步驟5：執(zhí)行查詢
String sql = "SELECT id, first, last, age FROM Employees";
ResultSet rs = stmt.executeQuery(sql);
System.out.println("List result set for reference....");
printRs(rs);
//步驟6：循環(huán)瀏覽結(jié)果集，并增加5個年齡
//移至BFR位置，以便while循環(huán)正常工作
rs.beforeFirst();
//步驟7：從結(jié)果集中提取數(shù)據(jù)
while(rs.next()){
//按列名檢索
int newAge = rs.getInt("age") + 5;
rs.updateDouble( "age", newAge );
rs.updateRow();
}
System.out.println("List result set showing new ages...");
printRs(rs);
// 在表中插入一條記錄。
//移動以使用updateXXX()插入行并添加列數(shù)據(jù)
System.out.println("Inserting a new record...");
rs.moveToInsertRow();
rs.updateInt("id",104);
rs.updateString("first","John");
rs.updateString("last","Paul");
rs.updateInt("age",40);
//提交行
rs.insertRow();
System.out.println("List result set showing new set...");
printRs(rs);
// 從表中刪除第二條記錄。
// 首先將位置設(shè)置為第二條記錄
rs.absolute( 2 );
System.out.println("List the record before deleting...");
//按列名檢索
int id = rs.getInt("id");
int age = rs.getInt("age");
String first = rs.getString("first");
String last = rs.getString("last");
//顯示值
System.out.print("ID: " + id);
System.out.print(", Age: " + age);
System.out.print(", First: " + first);
System.out.println(", Last: " + last);
//刪除行
rs.deleteRow();
System.out.println("List result set after \
deleting one records...");
printRs(rs);
//步驟8：清理環(huán)境
rs.close();
stmt.close();
conn.close();
}catch(SQLException se){
//處理JDBC錯誤
se.printStackTrace();
}catch(Exception e){
//處理Class.forName的錯誤
e.printStackTrace();
}finally{
//用于關(guān)閉資源
try{
if(conn!=null)
conn.close();
}catch(SQLException se){
se.printStackTrace();
}
}
System.out.println("Goodbye!");
}//結(jié)束main
public static void printRs(ResultSet rs) throws SQLException{
//確保我們從第一行開始
rs.beforeFirst();
while(rs.next()){
//按列名檢索
int id = rs.getInt("id");
int age = rs.getInt("age");
String first = rs.getString("first");
String last = rs.getString("last");
//顯示值
System.out.print("ID: " + id);
System.out.print(", Age: " + age);
System.out.print(", First: " + first);
System.out.println(", Last: " + last);
}
System.out.println();
}//結(jié)束printRs()
}//結(jié)束JDBCExample現(xiàn)在讓我們編譯上面的示例，如下所示：
C:\>javac JDBCExample.java C:\>
運行時JDBCExample，它將產(chǎn)生以下結(jié)果-
C:\>java JDBCExample Connecting to database... Creating statement... List result set for reference.... ID: 100, Age: 33, First: Zara, Last: Ali ID: 101, Age: 40, First: Mahnaz, Last: Fatma ID: 102, Age: 50, First: Zaid, Last: Khan ID: 103, Age: 45, First: Sumit, Last: Mittal List result set showing new ages... ID: 100, Age: 38, First: Zara, Last: Ali ID: 101, Age: 45, First: Mahnaz, Last: Fatma ID: 102, Age: 55, First: Zaid, Last: Khan ID: 103, Age: 50, First: Sumit, Last: Mittal Inserting a new record... List result set showing new set... ID: 100, Age: 38, First: Zara, Last: Ali ID: 101, Age: 45, First: Mahnaz, Last: Fatma ID: 102, Age: 55, First: Zaid, Last: Khan ID: 103, Age: 50, First: Sumit, Last: Mittal ID: 104, Age: 40, First: John, Last: Paul List the record before deleting... ID: 101, Age: 45, First: Mahnaz, Last: Fatma List result set after deleting one records... ID: 100, Age: 38, First: Zara, Last: Ali ID: 102, Age: 55, First: Zaid, Last: Khan ID: 103, Age: 50, First: Sumit, Last: Mittal ID: 104, Age: 40, First: John, Last: Paul Goodbye! C:\>