以下是使用Statement
物件的批次處理的典型步驟序列 -
createStatement()
方法建立Statement
物件。setAutoCommit()
將自動提交設定為false
。addBatch()
方法在建立的Statement
物件上新增SQL語句到批次處理中。Statement
物件上使用executeBatch()
方法執行所有SQL語句。commit()
方法提交所有更改。此範例程式碼是基於前面章節中完成的環境和資料庫設定編寫的。
以下程式碼片段提供了使用Statement
物件的批次更新範例,將下面程式碼儲存到檔案:BatchingWithStatement.java -
// Import required packages
// See more detail at /20/213/8320.html
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
編譯上面程式碼,如下 -
F:\worksp\jdbc>javac -Djava.ext.dirs=F:\worksp\jdbc\libs BatchingWithStatement.java
執行上面程式碼如下所示 -
F:\worksp\jdbc>java -Djava.ext.dirs=F:\worksp\jdbc\libs 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:\worksp\jdbc>