Interview Questions Answers.ORG
Interviewer And Interviewee Guide
Interviews
Quizzes
Home
Quizzes
Interviews Java Programming Language Interviews:Advanced JavaCore JavaEclipseFull Stack Developer (Java)HibernateIBM WebSphereInternationalization LocalizationJ2EEJ2MEJ2SEJavaJava ANTJava AppletJava BeansJava ClassesJava EJB ProgrammingJava Game DeveloperJava GUI FrameworkJava JNDIJava JNIJava JSP ProgrammingJava Message Service (JMS)Java Multi-ThreadingJava Networking - Sockets and RMIJava PatternsJava SecurityJava Server FacesJava Servlet ProgrammingJava Software EngineerJava Swing ProgrammingJava TechnicalJava ThreadsJava Transaction APIJava Web ServicesJavaMailJBossJDBCJMSJSFPortal and PortletRMISpring FrameworkSr.Java Web DeveloperStrutsSunOneSwing AWTSWT JFace
Copyright © 2018. All Rights Reserved
Sr.Java Web Developer Interview Question:
Please explain what is the difference between execute, executeQuery, executeUpdate?
Submitted by: MuhammadStatement execute(String query) is used to execute any SQL query and it returns TRUE if the result is an ResultSet such as running Select queries. The output is FALSE when there is no ResultSet object such as running Insert or Update queries. We can use getResultSet() to get the ResultSet and getUpdateCount() method to retrieve the update count.
Statement executeQuery(String query) is used to execute Select queries and returns the ResultSet. ResultSet returned is never null even if there are no records matching the query. When executing select queries we should use executeQuery method so that if someone tries to execute insert/update statement it will throw java.sql.SQLException with message “executeQuery method can not be used for update”.
Statement executeUpdate(String query) is used to execute Insert/Update/Delete (DML) statements or DDL statements that returns nothing. The output is int and equals to the row count for SQL Data Manipulation Language (DML) statements. For DDL statements, the output is 0.
You should use execute() method only when you are not sure about the type of statement else use executeQuery or executeUpdate method.
Submitted by: Muhammad
Statement executeQuery(String query) is used to execute Select queries and returns the ResultSet. ResultSet returned is never null even if there are no records matching the query. When executing select queries we should use executeQuery method so that if someone tries to execute insert/update statement it will throw java.sql.SQLException with message “executeQuery method can not be used for update”.
Statement executeUpdate(String query) is used to execute Insert/Update/Delete (DML) statements or DDL statements that returns nothing. The output is int and equals to the row count for SQL Data Manipulation Language (DML) statements. For DDL statements, the output is 0.
You should use execute() method only when you are not sure about the type of statement else use executeQuery or executeUpdate method.
Submitted by: Muhammad
Copyright 2007-2024 by Interview Questions Answers .ORG All Rights Reserved.
https://InterviewQuestionsAnswers.ORG.
https://InterviewQuestionsAnswers.ORG.