iBATIS-删除操作 - 芒果文档

📌 相关文章

📜 iBATIS-删除操作

📅 最后修改于: 2020-11-16 08:14:31 🧑 作者: Mango

本章介绍如何使用iBATIS从表中删除记录。

我们在MySQL中有以下EMPLOYEE表-

CREATE TABLE EMPLOYEE (
   id INT NOT NULL auto_increment,
   first_name VARCHAR(20) default NULL,
   last_name  VARCHAR(20) default NULL,
   salary     INT  default NULL,
   PRIMARY KEY (id)
);

假设此表具有两条记录，如下所示：

mysql> select * from EMPLOYEE;
+----+------------+-----------+--------+
| id | first_name | last_name | salary |
+----+------------+-----------+--------+
|  1 | Zara       | Ali       |   5000 |
|  2 | Roma       | Ali       |   3000 |
+----+------------+-----------+--------+
2 row in set (0.00 sec)

员工POJO班

要执行删除操作，您不需要修改Employee.java文件。让我们保持上一章的样子。

public class Employee {
   private int id;
   private String first_name; 
   private String last_name;   
   private int salary;  

   /* Define constructors for the Employee class. */
   public Employee() {}
  
   public Employee(String fname, String lname, int salary) {
      this.first_name = fname;
      this.last_name = lname;
      this.salary = salary;
   }

   /* Here are the required method definitions */
   public int getId() {
      return id;
   }
    
   public void setId(int id) {
      this.id = id;
   }
    
   public String getFirstName() {
      return first_name;
   }
    
   public void setFirstName(String fname) {
      this.first_name = fname;
   }
    
   public String getLastName() {
      return last_name;
   }
    
   public void setlastName(String lname) {
      this.last_name = lname;
   }
    
   public int getSalary() {
      return salary;
   }
    
   public void setSalary(int salary) {
      this.salary = salary;
   }

} /* End of Employee */

Employee.xml文件

要使用iBATIS定义SQL映射语句，我们将在Employee.xml中添加标记，并在该标记定义内，我们将定义一个“ id”，该ID将在IbatisDelete.java文件中用于对数据库执行SQL DELETE查询。






   
      INSERT INTO EMPLOYEE(first_name, last_name, salary)
      values (#first_name#, #last_name#, #salary#)

      
         select last_insert_id() as id
      
   

   

   
      UPDATE EMPLOYEE
      SET    first_name = #first_name#
      WHERE  id = #id#
   

   
      DELETE FROM EMPLOYEE
      WHERE  id = #id#

IbatisDelete.java文件

该文件具有应用程序级逻辑，可从Employee表中删除记录-

import com.ibatis.common.resources.Resources;
import com.ibatis.sqlmap.client.SqlMapClient;
import com.ibatis.sqlmap.client.SqlMapClientBuilder;

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

public class IbatisDelete{
   public static void main(String[] args)
   throws IOException,SQLException{
      Reader rd = Resources.getResourceAsReader("SqlMapConfig.xml");
      SqlMapClient smc = SqlMapClientBuilder.buildSqlMapClient(rd);

      /* This would delete one record in Employee table. */
      System.out.println("Going to delete record.....");
      int id = 1;

      smc.delete("Employee.delete", id );
      System.out.println("Record deleted Successfully ");

      System.out.println("Going to read records.....");
      List  ems = (List)
         smc.queryForList("Employee.getAll", null);
      Employee em = null;
        
      for (Employee e : ems) {
         System.out.print("  " + e.getId());
         System.out.print("  " + e.getFirstName());
         System.out.print("  " + e.getLastName());
         System.out.print("  " + e.getSalary());
         em = e; 
         System.out.println("");
      }    

      System.out.println("Records Read Successfully ");
   }
}

编译并运行

这是编译和运行上述软件的步骤。在继续进行编译和执行之前，请确保已正确设置了PATH和CLASSPATH。

如上所示创建Employee.xml。
如上所示创建Employee.java并进行编译。
如上所示创建IbatisDelete.java并进行编译。
执行IbatisDelete二进制文件以运行程序。

您将得到以下结果，并且ID = 1的记录将从EMPLOYEE表中删除，其余的记录将被读取。

Going to delete record.....
Record deleted Successfully
Going to read records.....
   2  Roma  Ali  3000
Records Read Successfully