JDBC-貧勧才指獄箭徨
參和議箭徨繍氏喘欺岻念戻欺議commit才rollback。
幣箭旗鷹児噐岻念譜崔議桟廠才方象垂園亟。
鹸崙娚薮旗鷹欺JDBCExample.java?園咎塰佩泌和?
園咎貧峰旗鷹?
輝低塰佩JDBCExample議扮昨?恢伏泌和補竃?
幣箭旗鷹児噐岻念譜崔議桟廠才方象垂園亟。
鹸崙娚薮旗鷹欺JDBCExample.java?園咎塰佩泌和?
//STEP 1. Import required packages
import java.sql.*;
public class JDBCExample {
// JDBC driver name and database URL
static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";
static final String DB_URL = "jdbc:mysql://localhost/EMP";
// Database credentials
static final String USER = "username";
static final String PASS = "password";
public static void main(String[] args) {
Connection conn = null;
Statement stmt = null;
try{
//STEP 2: Register JDBC driver
Class.forName("com.mysql.jdbc.Driver");
//STEP 3: Open a connection
System.out.println("Connecting to database...");
conn = DriverManager.getConnection(DB_URL,USER,PASS);
//STEP 4: Set auto commit as false.
conn.setAutoCommit(false);
//STEP 5: Execute a query to create statment with
// required arguments for RS example.
System.out.println("Creating statement...");
stmt = conn.createStatement(
ResultSet.TYPE_SCROLL_INSENSITIVE,
ResultSet.CONCUR_UPDATABLE);
//STEP 6: INSERT a row into Employees table
System.out.println("Inserting one row....");
String SQL = "INSERT INTO Employees " +
"VALUES (106, 20, 'Rita', 'Tez')";
stmt.executeUpdate(SQL);
//STEP 7: INSERT one more row into Employees table
SQL = "INSERT INTO Employees " +
"VALUES (107, 22, 'Sita', 'Singh')";
stmt.executeUpdate(SQL);
//STEP 8: Commit data here.
System.out.println("Commiting data here....");
conn.commit();
//STEP 9: Now list all the available records.
String sql = "SELECT id, first, last, age FROM Employees";
ResultSet rs = stmt.executeQuery(sql);
System.out.println("List result set for reference....");
printRs(rs);
//STEP 10: Clean-up environment
rs.close();
stmt.close();
conn.close();
}catch(SQLException se){
//Handle errors for JDBC
se.printStackTrace();
// If there is an error then rollback the changes.
System.out.println("Rolling back data here....");
try{
if(conn!=null)
conn.rollback();
}catch(SQLException se2){
se2.printStackTrace();
}//end try
}catch(Exception e){
//Handle errors for Class.forName
e.printStackTrace();
}finally{
//finally block used to close resources
try{
if(stmt!=null)
stmt.close();
}catch(SQLException se2){
}// nothing we can do
try{
if(conn!=null)
conn.close();
}catch(SQLException se){
se.printStackTrace();
}//end finally try
}//end try
System.out.println("Goodbye!");
}//end main
public static void printRs(ResultSet rs) throws SQLException{
//Ensure we start with first row
rs.beforeFirst();
while(rs.next()){
//Retrieve by column name
int id = rs.getInt("id");
int age = rs.getInt("age");
String first = rs.getString("first");
String last = rs.getString("last");
//Display values
System.out.print("ID: " + id);
System.out.print(", Age: " + age);
System.out.print(", First: " + first);
System.out.println(", Last: " + last);
}
System.out.println();
}//end printRs()
}//end JDBCExample
園咎貧峰旗鷹?
C:>javac JDBCExample.java C:>
輝低塰佩JDBCExample議扮昨?恢伏泌和補竃?
C:>java JDBCExample Connecting to database... Creating statement... Inserting one row.... Commiting data here.... List result set for reference.... ID: 100, Age: 18, First: Zara, Last: Ali ID: 101, Age: 25, First: Mahnaz, Last: Fatma ID: 102, Age: 30, First: Zaid, Last: Khan ID: 103, Age: 28, First: Sumit, Last: Mittal ID: 106, Age: 20, First: Rita, Last: Tez ID: 107, Age: 22, First: Sita, Last: Singh Goodbye! C:>