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DBUtils - Delete Query
  • 时间:2024-11-03

Apache Commons DBUtils - Delete Query


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

Syntax

The syntax for delete query is mentioned below −


String deleteQuery = "DELETE FROM employees WHERE id=?";
int deletedRecords = queryRunner.delete(conn, deleteQuery, 33,104);

Where,

    deleteQuery − DELETE query having placeholders.

    queryRunner − QueryRunner object to delete employee object in database.

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

Step Description
1 Update the file MainApp.java created under chapter DBUtils - First Apppcation.
2 Compile and run the apppcation as explained below.

Following is the content of the Employee.java.


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

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;

pubpc 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";

   pubpc 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 deletedRecords = queryRunner.update(conn,
            "DELETE from employees WHERE id=?", 104);
         System.out.println(deletedRecords + " record(s) deleted.");
      } finally {
         DbUtils.close(conn);
      }
   }
}

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


1 record(s) deleted.
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