JDBC- PreparedStatement example - Execute DELETE query(DML command) using PreparedStatement's executeUpdate method in java


In this tutorial we will learn how to Execute DELETE query(DML command) using PreparedStatement's executeUpdate method in java JDBC.



JDBC tutorial - What is java.sql.CallableStatement in java


java.sql.PreparedStatement's executeUpdate method can be used for executing delete queries and
executeUpdate method returns number of rows deleted



--Before executing java program execute these database scripts  >
create table EMPLOYEE(ID number(4), NAME varchar2(22));
insert into EMPLOYEE values(7, 'ankit');
insert into EMPLOYEE values(8, 'rohit');
commit;

--If table already exists then execute the DROP command >
drop table EMPLOYEE;



Before execution of below program EMPLOYEE table will look like this >


After execution of below program EMPLOYEE table will look like this >



Example/ Full Programs JDBC- Execute DELETE query using PreparedStatement's executeUpdate method in java
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
/** Copyright (c), AnkitMittal JavaMadeSoEasy.com */
public class PreparedStatementDeleteExample {
   public static void main(String... arg) {
          Connection con = null;
          PreparedStatement prepStmt = null;
          try {
                 // registering Oracle driver class
                 Class.forName("oracle.jdbc.driver.OracleDriver");
                 // getting connection
                 con = DriverManager.getConnection(
                              "jdbc:oracle:thin:@localhost:1521:orcl",
                              "ankit", "Oracle123");
                 System.out.println("Connection established successfully!");
                
                
                 prepStmt = con.prepareStatement("DELETE from EMPLOYEE where ID=? ");
                 prepStmt.setInt(1, 8); //substitute first occurrence of ? with 8
                 // execute delete query
                 int numberOfRowsDeleted = prepStmt.executeUpdate();
                 System.out.println("numberOfRowsDeleted=" + numberOfRowsDeleted);
          } catch (ClassNotFoundException e) {
                 e.printStackTrace();
          } catch (SQLException e) {
                 e.printStackTrace();
          }
          finally{
                 try {
                       if(prepStmt!=null) prepStmt.close(); //close PreparedStatement
                       if(con!=null) con.close(); // close connection
                 } catch (SQLException e) {
                       e.printStackTrace();
                 }
          }
   }
}
/*OUTPUT
Connection established successfully!
numberOfRowsDeleted=1
*/


Must read : java.sql.PreparedStatement - using executeUpdate  and executeQuery methods - CREATE, SELECT, INSERT and UPDATE


Must Know :

By default connection is auto-commit, so all delete queries will be committed automatically.
(Also must know : delete is a DML(Data Manipulation Language) command, queries are not committed automatically in database)

We may stop connection from doing auto-commits by setting auto-commit to false using > con.setAutoCommit(false);
Well in that we may commit transactions any time using con.commit();

Also, We may set connection back to default behavior of doing auto-commit by using > con.setAutoCommit(true) or simply using con.setAutoCommit();

But what will be benefit of using con.setAutoCommit(false)?
If any transaction goes wrong than we may halt execution further related transactions before calling con.commit() and call con.rollback() in catch block.


So, in this tutorial we learned how to Execute DELETE query(DML command) using PreparedStatement's executeUpdate method in java JDBC.



RELATED LINKS>

java.sql.PreparedStatement - using executeUpdate  and executeQuery methods - CREATE, SELECT, INSERT, UPDATE and DELETE in java.



Execute database STORED PROCEDURE - IN parameter, OUT parameter and IN OUT parameter || call FUNCTION from java

Difference between CLOB and CLOB data type in Oracle


JDBC tutorial- Insert/Store/save FILE in database

JDBC program- Batch PreparedStatement example- Execute INSERT query(DML command) using PreparedStatement's addBatch() and executeBatch() methods in java


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