zoukankan      html  css  js  c++  java
  • 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");
          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();
       rs.close();
    }//end printRows()
    }//end JDBCExample
    
    SQL

    编译上面代码,如下 -

    F:workspjdbc>javac -Djava.ext.dirs=F:workspjdbclibs BatchingWithStatement.java
    
    Shell

    执行上面代码如下所示 -

    F:workspjdbc>java -Djava.ext.dirs=F:workspjdbclibs BatchingWithStatement
    Connecting to database...
    Thu Jun 01 04:41:05 CST 2017 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.
    Creating statement...
    Displaying available rows...
    ID: 100, Age: 28, First: Max, Last: Su
    ID: 101, Age: 25, First: Wei, Last: Wang
    ID: 102, Age: 35, First: Xueyou, Last: Zhang
    ID: 103, Age: 30, First: Jack, Last: Ma
    ID: 106, Age: 28, First: Curry, Last: Stephen
    ID: 107, Age: 32, First: Kobe, Last: Bryant
    
    Displaying available rows...
    ID: 100, Age: 35, First: Max, Last: Su
    ID: 101, Age: 25, First: Wei, Last: Wang
    ID: 102, Age: 35, First: Xueyou, Last: Zhang
    ID: 103, Age: 30, First: Jack, Last: Ma
    ID: 106, Age: 28, First: Curry, Last: Stephen
    ID: 107, Age: 32, First: Kobe, Last: Bryant
    ID: 200, Age: 30, First: Curry, Last: Stephen
    ID: 201, Age: 35, First: Kobe, Last: Bryant
    
    Goodbye!
    
    F:workspjdbc>
    
    Shell
     
  • 相关阅读:
    关于隐藏元素高度的问题 css visibility:hidden 与 display:none的区别
    三星R428 内存不兼容金士顿2G DDR3
    IE (6-11)版本,在使用iframe的框架时,通过a标签javascript:; 和js跳转parent.location的时候 出现在新页面打开的情况
    按键精灵 vbs 获取网页源码 xp系统被拒绝
    threejs 组成的3d管道,寻最短路径问题
    javaweb部署多个项目(复制的项目)
    添加无登录权限的SSH用户命令
    Using Blocks in iOS 4: Designing with Blocks
    Using Blocks in iOS 4: The Basics
    Understanding Objective-C Blocks
  • 原文地址:https://www.cnblogs.com/borter/p/9608792.html
Copyright © 2011-2022 走看看