iBATIS刪除操作
本章將教你如何從表中使用iBATIS刪除記錄。
我們已經在MySQL下有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) );
假設這個表是有兩條記錄如下：
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)
Employee POJO 類:
要執行刪除操作，就需要修改Employee.java文件。因此，讓我們保持它不變，在上一章我們使用過。
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:
要定義使用iBATIS SQL映射語句中，我們將增加
<sqlMap namespace="Employee"> <insert id="insert" parameterClass="Employee"> INSERT INTO EMPLOYEE(first_name, last_name, salary)
values (#first_name#, #last_name#, #salary#) <selectKey resultClass="int" keyProperty="id"> select last_insert_id() as id <select id="getAll" resultClass="Employee"> SELECT * FROM EMPLOYEE <update id="update" parameterClass="Employee"> UPDATE EMPLOYEE
SET first_name = #first_name#
WHERE id = #id# <delete id="delete" parameterClass="int"> DELETE FROM EMPLOYEE
WHERE id = #id#
IbatisDelete.java 文件:
文件將應用程序級別的邏輯從Employee表中刪除記錄：
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 <Employee> ems = (List<Employee>) 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 "); } }
編譯和運行：
下面是步驟來編譯並運行上述軟件。請確保已在進行的編譯和執行之前，適當地設置PATH和CLASSPATH。
創建Employee.xml如上所示。
創建Employee.java如上圖所示，並編譯它。
創建IbatisDelete.java如上圖所示，並編譯它。
執行IbatisDelete二進制文件來運行程序。
得到以下結果，ID=1將在EMPLOYEE表中被刪除，並讀取EMPLOYEE表中的一條記錄。
Going to delete record..... Record deleted Successfully Going to read records..... 2 Roma Ali 3000 Records Read Successfully