Question

我是Java编程的初学者。我试图从一个oracle数据库表中获取数据并使用下面的java代码插入另一个数据库表，并且它是成功的。但是，我不知道在此代码中实现批量插入逻辑和增加的提取大小。任何人都可以帮忙。我的目标是获取100行并在一次往返中插入100行而不是逐个插入。提前谢谢。

import java.sql.*;
import java.io.*;
import java.util.*;


public class Dbtodb {
    public static void main(String[] args) {
        try
{
Connection con = DriverManager.getConnection( "jdbc:oracle:thin:@ipaddress1:port1:server1","user1","password1");
Connection con1 = DriverManager.getConnection( "jdbc:oracle:thin:@ipaddress2:port2:server2","user2","password2");
String sql = "INSERT INTO test_GROUPS("+ "GROUP_NO,"+ "GROUP_NAME,"+ "BUYER,"+ " MERCH,"+" DIVISION)"+ "VALUES(?,?,?,?,?)";
Statement statement = 
con.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_UPDATABLE);  
PreparedStatement pstmt = con1.prepareStatement(sql);
ResultSet rs = statement.executeQuery("SELECT * FROM groups"); 
while ( rs.next() )  
{  
    int gpnum = rs.getInt(1);
String gpname = rs.getString(2);
    int byr = rs.getInt(3);
    int merch = rs.getInt(4);
    int divisn = rs.getInt(5);
pstmt.setInt(1, gpnum);       
pstmt.setString(2, gpname);
pstmt.setInt(3, byr);          
pstmt.setInt(4, merch);   
pstmt.setInt(5, divisn);   
pstmt.executeUpdate();
} 
con.close();
con1.close();
}
catch (SQLException e)
{
System.out.println("could not get JDBC connection: " +e); 
}

    }
}

Answer 1

一次获取100行：

PreparedStatement pstmt = con1.prepareStatement(sql);
((OraclePreparedStatement)pstmt).setExecuteBatch(100); // <-- Add this
ResultSet rs = statement.executeQuery("SELECT * FROM groups");

一次插入100行：

pstmt.executeUpdate()

...以上内容将改变((OraclePreparedStatement)pstmt).sendBatch(); // <-- This ensures that any queued inserts get sent to the database. con.close(); con1.close();的行为，以便累积插入内容，并在达到批量大小后将其发送到数据库。

您还需要进行一次最后的小改动，以确保始终发送最后一批产品：

"search.exclude": {
    "**/node_modules": false,
    "node_modules": true
}

文档链接：

从一个oracle数据库中选择并使用java

1 个答案: