JDBC Statement對象執行批量處理實例
阿新 • • 發佈:2018-09-08
mysql turned resources block change cert turn set catch -
以下是使用Statement
對象的批處理的典型步驟序列 -
- 使用
createStatement()
方法創建Statement
對象。 - 使用
setAutoCommit()
將自動提交設置為false
。 - 使用
addBatch()
方法在創建的Statement
對象上添加SQL語句到批處理中。 - 在創建的
Statement
對象上使用executeBatch()
方法執行所有SQL語句。 - 最後,使用
commit()
方法提交所有更改。
此示例代碼是基於前面章節中完成的環境和數據庫設置編寫的。
以下代碼片段提供了使用Statement
對象的批量更新示例,將下面代碼保存到文件: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")