Java Programming

Java MCQ: Which annotation is used to mark a class as an entity listener in JPA? a) @EntityListener b) @Entity c) @Listener d) @EntityListeners Answer: d) @EntityListeners Explanation: The @EntityListeners annotation in JPA is used to mark a class or method as an entity listener. Entity listeners are used to intercept entity lifecycle events such […]

Java MCQ: What is the purpose of the @Embeddable annotation in JPA? a) To define an entity b) To define a composite primary key c) To define an embeddable class d) To specify a named query Answer: c) To define an embeddable class Explanation: The @Embeddable annotation in JPA is used to define an embeddable

Java MCQ: Which annotation is used to mark an entity as read-only in Hibernate? a) @Immutable b) @Transient c) @ReadOnly d) @Entity Answer: a) @Immutable Explanation: The @Immutable annotation in Hibernate is used to mark an entity as read-only. When an entity is annotated with @Immutable, Hibernate will not allow any modifications to the entity’s

Java MCQ: What does the @Inheritance annotation in JPA specify? a) It defines a column inheritance strategy b) It specifies the table inheritance strategy c) It marks an entity as abstract d) It defines a primary key generation strategy Answer: b) It specifies the table inheritance strategy Explanation: The @Inheritance annotation in JPA specifies the

Java MCQ: What is the role of the @JoinColumn annotation in JPA? a) It defines a foreign key column in a table b) It maps a field to a database column c) It specifies a named query d) It defines the table name Answer: a) It defines a foreign key column in a table Explanation:

Java MCQ: Which JPA annotation is used to define a many-to-many relationship? a) @OneToMany b) @ManyToMany c) @OneToOne d) @ManyToOne Answer: b) @ManyToMany Explanation: The @ManyToMany annotation is used to define a many-to-many relationship in JPA. This type of relationship means that multiple instances of one entity can be associated with multiple instances of another

Java MCQ: Which annotation is used to specify a query in JPA? a) @Query b) @NamedQuery c) @SQL d) @Select Answer: b) @NamedQuery Explanation: The @NamedQuery annotation is used in JPA to specify a named query. Named queries are pre-defined, static queries that are associated with an entity and can be executed multiple times with

Java MCQ: Which annotation is used to define a one-to-one relationship in JPA? a) @OneToOne b) @OneToMany c) @ManyToOne d) @ManyToMany Answer: a) @OneToOne Explanation: The @OneToOne annotation is used to define a one-to-one relationship in JPA. This type of relationship indicates that one instance of an entity is associated with exactly one instance of

Java MCQ: Which JPA annotation is used to define a one-to-many relationship? a) @ManyToMany b) @OneToOne c) @OneToMany d) @ManyToOne Answer: c) @OneToMany Explanation: The @OneToMany annotation is used to define a one-to-many relationship in JPA. This type of relationship indicates that one instance of an entity is associated with many instances of another entity.

Java MCQ: Which annotation is used to define a many-to-one relationship in JPA? a) @OneToMany b) @ManyToOne c) @OneToOne d) @ManyToMany Answer: b) @ManyToOne Explanation: The @ManyToOne annotation is used to define a many-to-one relationship in JPA. This type of relationship means that many instances of an entity can be associated with one instance of

Java MCQ: Which JPA annotation is used to define the table name for an entity? a) @Entity b) @Table c) @Column d) @PersistenceTable Answer: b) @Table Explanation: The @Table annotation in JPA is used to define the table name for an entity. This annotation is applied at the class level and specifies the name of

Java MCQ: Which annotation is used to automatically generate primary key values in JPA? a) @AutoKey b) @Id c) @GeneratedValue d) @KeyGenerator Answer: c) @GeneratedValue Explanation: The @GeneratedValue annotation is used in JPA to automatically generate primary key values. This annotation is applied to the primary key field of an entity and allows the database

Java MCQ: Which JPA annotation is used to define a column in a database table? a) @Table b) @Field c) @Column d) @Mapping Answer: c) @Column Explanation: The @Column annotation in JPA is used to define a column in a database table. It is applied to a field or property of an entity class and

Java MCQ: Which annotation is used to specify the primary key of an entity in JPA? a) @PrimaryKey b) @Id c) @Key d) @GeneratedValue Answer: b) @Id Explanation: The @Id annotation is used to specify the primary key of an entity in JPA. The field or property annotated with @Id represents the unique identifier for

Java MCQ: Which annotation is used to mark a class as an entity in JPA? a) @Table b) @Column c) @Entity d) @Persistence Answer: c) @Entity Explanation: The @Entity annotation is used to mark a class as an entity in JPA. An entity represents a table in the database, and each instance of the entity

Java MCQ: What does JPA stand for? a) Java Persistence API b) Java Platform API c) Java Performance API d) Java Process API Answer: a) Java Persistence API Explanation: JPA stands for Java Persistence API. It is a specification in Java that provides a standard for object-relational mapping (ORM) and data persistence. JPA allows developers

Java MCQ: Which method is used to close a JDBC connection? a) terminate() b) close() c) shutdown() d) disconnect() Answer: b) close() Explanation: The close() method is used to close a JDBC connection. This method is called on the Connection object to release the database resources associated with the connection. It is important to close

Java MCQ: Which JDBC interface is used for batch updates? a) Statement b) PreparedStatement c) BatchStatement d) BatchUpdate Answer: a) Statement Explanation: The Statement interface in JDBC is used for batch updates. Batch updates allow you to execute multiple SQL statements as a single batch, which can improve performance by reducing the number of database

Java MCQ: Which method is used to rollback a transaction in JDBC? a) undoTransaction() b) rollbackTransaction() c) rollback() d) revert() Answer: c) rollback() Explanation: The rollback() method is used to rollback a transaction in JDBC. When auto-commit mode is disabled, you can use rollback() on the Connection object to undo all changes made in the

Java MCQ: Which JDBC method is used to commit a transaction? a) commitTransaction() b) executeCommit() c) commit() d) finalizeTransaction() Answer: c) commit() Explanation: The commit() method is used to commit a transaction in JDBC. When auto-commit mode is disabled, multiple SQL statements can be grouped into a single transaction. After executing all the statements, calling

Java MCQ: What is the role of the ResultSet interface in JDBC? a) To manage database connections b) To execute SQL queries c) To retrieve and manipulate query results d) To manage SQL transactions Answer: c) To retrieve and manipulate query results Explanation: The ResultSet interface in JDBC is used to retrieve and manipulate the

Java MCQ: Which interface is used to execute SQL queries in JDBC? a) Statement b) ResultSet c) Connection d) PreparedStatement Answer: a) Statement Explanation: The Statement interface is used to execute SQL queries in JDBC. It provides methods to execute SQL statements, such as executeQuery() for SELECT statements, executeUpdate() for INSERT, UPDATE, and DELETE statements,

Java MCQ: Which method is used to establish a connection to a database? a) DriverManager.connect() b) DriverManager.getConnection() c) Connection.create() d) Database.connect() Answer: b) DriverManager.getConnection() Explanation: The DriverManager.getConnection() method is used to establish a connection to a database in JDBC. This method takes a database URL, a username, and a password as arguments and returns a

Java MCQ: Which package contains the JDBC API? a) java.sql b) javax.jdbc c) java.database d) javax.sql Answer: a) java.sql Explanation: The java.sql package contains the JDBC API. This package provides the necessary classes and interfaces for connecting to databases, executing SQL queries, and processing the results. Some of the key classes and interfaces in java.sql

Java MCQ: What does JDBC stand for? a) Java Data Connection b) Java Database Connectivity c) Java DataBase Compiler d) Java Data Component Answer: b) Java Database Connectivity Explanation: JDBC stands for Java Database Connectivity. It is an API in Java that allows developers to connect to and interact with databases from Java applications. JDBC