Dbutils 简明教程

Apache Commons DBUtils - Create Query

以下示例将演示如何使用 DBUtils 借助 Insert 查询来创建记录。我们将在 Employees 表中插入一条记录。

The following example will demonstrate how to create a record using Insert query with the help of DBUtils. We will insert a record in Employees Table.

Syntax

创建查询的语法如下 −

The syntax to create a query is given below −

String insertQuery ="INSERT INTO employees(id,age,first,last) VALUES (?,?,?,?)";
int insertedRecords = queryRunner.update(conn, insertQuery,104,30, "Sohan","Kumar");

其中，

Where,

  1. insertQuery − Insert query having placeholders.

  2. queryRunner − QueryRunner object to insert employee object in database.

为了理解与 DBUtils 相关的以上概念，我们来编写一个示例，该示例将运行一个插入查询。为了编写示例，我们来创建一个示例应用程序。

To understand the above-mentioned concepts related to DBUtils, let us write an example which will run an insert query. To write our example, let us create a sample application.

Step

Description

1

Update the file MainApp.java created under chapter DBUtils - First Application.

2

Compile and run the application as explained below.

以下是 Employee.java 的内容。

Following is the content of the Employee.java.

public class Employee {
   private int id;
   private int age;
   private String first;
   private String last;
   public int getId() {
      return id;
   }
   public void setId(int id) {
      this.id = id;
   }
   public int getAge() {
      return age;
   }
   public void setAge(int age) {
      this.age = age;
   }
   public String getFirst() {
      return first;
   }
   public void setFirst(String first) {
      this.first = first;
   }
   public String getLast() {
      return last;
   }
   public void setLast(String last) {
      this.last = last;
   }
}

以下是 MainApp.java 文件的内容。

Following is the content of the MainApp.java file.

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

import org.apache.commons.dbutils.DbUtils;
import org.apache.commons.dbutils.QueryRunner;

public class MainApp {
   // JDBC driver name and database URL
   static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";
   static final String DB_URL = "jdbc:mysql://localhost:3306/emp";

   // Database credentials
   static final String USER = "root";
   static final String PASS = "admin";
   public static void main(String[] args) throws SQLException {
      Connection conn = null;
      QueryRunner queryRunner = new QueryRunner();
      DbUtils.loadDriver(JDBC_DRIVER);
      conn = DriverManager.getConnection(DB_URL, USER, PASS);
      try {
         int insertedRecords = queryRunner.update(conn,
            "INSERT INTO employees(id,age,first,last) VALUES (?,?,?,?)",
            104,30, "Sohan","Kumar");
         System.out.println(insertedRecords + " record(s) inserted");
      } finally {
         DbUtils.close(conn);
      }
   }
}

一旦完成创建源文件，我们就来运行应用程序。如果你的应用程序一切正常，它将打印出以下消息 −

Once you are done creating the source files, let us run the application. If everything is fine with your application, it will print the following message −

1 record(s) inserted.