2021-04-20 08:26  阅读(104)
文章分类:Java JDBC 教程 文章标签:JavaJDBC
©  原文作者:易百教程 原文地址:https://www.yiibai.com/jdbc

以下是使用PrepareStatement对象进行批处理的典型步骤顺序 -

  • 使用占位符创建SQL语句。
  • 使用prepareStatement()方法创建PrepareStatement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PrepareStatement对象的批量更新示例,将下面代码保存到文件:BatchingWithPrepareStatement.java -

    // Import required packages
    // See more detail at http://www.yiibai.com/jdbc/
    
    import java.sql.*;
    
    public class BatchingWithPrepareStatement {
       // 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;
       PreparedStatement 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 SQL statement
          String SQL = "INSERT INTO Employees(id,first,last,age) " +
                       "VALUES(?, ?, ?, ?)";
    
          // Create preparedStatemen
          System.out.println("Creating statement...");
          stmt = conn.prepareStatement(SQL);
    
          // Set auto-commit to false
          conn.setAutoCommit(false);
    
          // First, let us select all the records and display them.
          printRows( stmt );
    
          // Set the variables
          stmt.setInt( 1, 400 );
          stmt.setString( 2, "Python" );
          stmt.setString( 3, "Zhang" );
          stmt.setInt( 4, 33 );
          // Add it to the batch
          stmt.addBatch();
    
          // Set the variables
          stmt.setInt( 1, 401 );
          stmt.setString( 2, "C++" );
          stmt.setString( 3, "Huang" );
          stmt.setInt( 4, 31 );
          // Add it to the batch
          stmt.addBatch();
    
          // 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
    

编译上面代码,如下 -

    F:\worksp\jdbc>javac -Djava.ext.dirs=F:\worksp\jdbc\libs BatchingWithPrepareStatement.java
    

执行上面代码如下所示 -

    F:\worksp\jdbc>javac -Djava.ext.dirs=F:\worksp\jdbc\libs BatchingWithPrepareStatement.java
    
    F:\worksp\jdbc>java -Djava.ext.dirs=F:\worksp\jdbc\libs BatchingWithPrepareStatement
    Connecting to database...
    Thu Jun 01 04:46:38 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: 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
    
    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
    ID: 400, Age: 33, First: Python, Last: Zhang
    ID: 401, Age: 31, First: C++, Last: Huang
    
    Goodbye!
    
    F:\worksp\jdbc>
    
点赞(0)
版权归原创作者所有,任何形式转载请联系作者; Java 技术驿站 >> JDBC PrepareStatement对象执行批量处理实例
上一篇
JDBC Statement对象执行批量处理实例
下一篇
JDBC存储过程调用