U3.2. Statements (JDBC)

What is a Statement in Java?

• It is used for static SQL statements at runtime and cannot accept parameters.

• It is used for complex database transactions only.

• It is specifically for calling stored procedures.

• It is for batch processing only.

What is the main advantage of using a PreparedStatement?

• It supports complex queries without any parameters.

• It allows SQL statements to be reused and accepts input parameters.

• It can only handle static SQL queries.

• It is specifically for creating tables in a database.

Which interface allows access to stored procedures in a database?

• Statement

• PreparedStatement

• CallableStatement

• ResultSet

What does the executeQuery(String sql) method of Statement return?

• An integer representing affected rows.

• A boolean value indicating success or failure.

• A ResultSet with the data from the query.

• A message indicating the SQL syntax status.

What is returned by executeUpdate(String sql) when executing a DDL command like CREATE TABLE?

• 1

• 0

• The number of columns created

• The table structure

Answer explanation

• For making DDL statements:

int executeUpdate(String sql);

• Returns int that is always 0 because DDL commands do not affect any rows of data; they only alter the schema.

In a ResultSet, which method moves the cursor to the next row?

• move()

• next()

• advance()

• previous()

To retrieve a column value by its index in a ResultSet, which method is used?

• getColumn()

• getInt()

• getString()

• getXXX(int columnIndex)

Answer explanation

getInt(int columnIndex)

getBoolean(int columnIndex)

getString(int columnIndex)

int id = resultset.getInt(1);

String name = resultset.getString(2);

Which method in ResultSetMetaData returns the number of columns in a ResultSet?

• getColumnCount()

• getColumnName()

• getMetaData()

• getRowCount()

What is the purpose of con.createStatement() in JDBC?

• To initialize a connection to the database.

• To create a new SQL statement object for executing SQL commands.

• To create a new table in the database.

• To close the current database connection.

Which of the following explains correctly the behavior of the following SELECT statement in JDBC?

Statement stt = con.createStatement();

String query = "SELECT * FROM champions WHERE name='Tryndamere'";

ResultSet rs = stt.executeQuery(query);

• The code will produce a compilation error.

• The statement will return the rows where name is 'Tryndamere'.

• The statement will delete the rows where name is 'Tryndamere'.

• It will create a new row with name set to 'Tryndamere'.