JDBC Statement对象执行批量处理实例

以下是使用Statement对象的批处理的典型步骤序列 -

• 使用createStatement()方法创建Statement对象。
• 使用setAutoCommit()将自动提交设置为false。
• 使用addBatch()方法在创建的Statement对象上添加SQL语句到批处理中。
• 在创建的Statement对象上使用executeBatch()方法执行所有SQL语句。
• 最后，使用commit()方法提交所有更改。

此示例代码是基于前面章节中完成的环境和数据库设置编写的。

以下代码片段提供了使用Statement对象的批量更新示例，将下面代码保存到文件：BatchingWithStatement.java -

// Import required packages
// See more detail at http://www.yiibai.com/jdbc/

import java.sql.*;

public class BatchingWithStatement {
   // 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 = "root";
   static final String PASS = "123456";

   public static void main(String[] args) {
   Connection conn = null;
   Statement stmt = null;
   try{
      // Register JDBC driver
      Class.forName("com.mysql.jdbc.Driver");

      // Open a connection
      System.out.println("Connecting to database...");
      conn = DriverManager.getConnection(DB_URL,USER,PASS);

      // Create statement
      System.out.println("Creating statement...");
      stmt = conn.createStatement();

      // Set auto-commit to false
      conn.setAutoCommit(false);

      // First, let us select all the records and display them.
      printRows( stmt );

      // Create SQL statement
      String SQL = "INSERT INTO Employees (id, first, last, age) " + 
                   "VALUES(200,'Curry', 'Stephen', 30)";
      // Add above SQL statement in the batch.
      stmt.addBatch(SQL);

      // Create one more SQL statement
      SQL = "INSERT INTO Employees (id, first, last, age) " +
            "VALUES(201,'Kobe', 'Bryant', 35)";
      // Add above SQL statement in the batch.
      stmt.addBatch(SQL);

      // Create one more SQL statement
      SQL = "UPDATE Employees SET age = 35 " +
            "WHERE id = 100";
      // Add above SQL statement in the batch.
      stmt.addBatch(SQL);

      // Create an int[] to hold returned values
      int[] count = stmt.executeBatch();

      //Explicitly commit statements to apply changes
      conn.commit();

      // Again, let us select all the records and display them.
      printRows( stmt );

      // Clean-up environment
      stmt.close();
      conn.close();
   }catch(SQLException se){
      //Handle errors for JDBC
      se.printStackTrace();
   }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 printRows(Statement stmt) throws SQLException{
   System.out.println("Displaying available rows...");
   // Let us select all the records and display them.
   String sql = "SELECT id, first, last, age FROM Employees";
   ResultSet rs = stmt.executeQuery(sql);

   while(rs.next()){
      //Retrieve by column name
      int id  = rs.getInt("id");
      int age = rs.getInt("age");
      String first = rs.getString("first"