- What happens if ResultSet is not closed?
- Do I need to close PreparedStatement?
- What is a DataSource in terms of JDBC?
- How can you retrieve information from a ResultSet *?
- What is the return type of next () method in ResultSet?
- Does closing ResultSet close connection?
- Do you need to close ResultSet?
- Which method is used for an SQL statement that is executed frequently?
- What happens if you call deleteRow () on a ResultSet object?
- Which of the following is used to call stored procedure?
- Which of the following is correct about PreparedStatement?
- What is a DataSource in JDBC?
What happens if ResultSet is not closed?
It is best to close the resources that you open as unexpected behavior can occur in regards to the JVM and system resources.
Additionally, some JDBC pooling frameworks pool Statements and Connections, so not closing them might not mark those objects as free in the pool, and cause performance issues in the framework..
Do I need to close PreparedStatement?
Even though every Statement and PreparedStatement is specified to be implicitly closed when the Connection object is closed, you can’t be guaranteed when (or if) this happens, especially if it’s used with connection pooling. You should explicitly close your Statement and PreparedStatement objects to be sure.
What is a DataSource in terms of JDBC?
JDBC data sources include options that determine the identity of the data source, way the data is handled on a database connection, and the way transactions are handled when a connection from the data source is used in a global transaction.
How can you retrieve information from a ResultSet *?
The ResultSet interface declares getter methods (for example, getBoolean and getLong ) for retrieving column values from the current row. You can retrieve values using either the index number of the column or the alias or name of the column.
What is the return type of next () method in ResultSet?
The next method moves the cursor to the next row, and because it returns false when there are no more rows in the ResultSet object, it can be used in a while loop to iterate through the result set. A default ResultSet object is not updatable and has a cursor that moves forward only.
Does closing ResultSet close connection?
Closing Connection will close any Statement s that connection has created. Closing any Statement will close all ResultSet s that were created by that Statement . Doesn’t matter if Connection is poolable or not. Even poolable connection has to clean before returning to the pool.
Do you need to close ResultSet?
You should close ResultSet and Statement explicitly because Oracle has problems previously with keeping the cursors open even after closing the connection. If you don’t close the ResultSet (cursor) it will throw an error like Maximum open cursors exceeded.
Which method is used for an SQL statement that is executed frequently?
prepareStatement methodprepareStatement method is used for an SQL statement that is executed frequently – JDBC.
What happens if you call deleteRow () on a ResultSet object?
The deleteRow() method of the ResultSet interface deletes the current row from the ResultSet object and from the table.
Which of the following is used to call stored procedure?
Which of the following is used to call stored procedure? Explanation: CallableStatement is used in JDBC to call stored procedure from Java program.
Which of the following is correct about PreparedStatement?
Q 19 – Which of the following is correct about PreparedStatement? A – PreparedStatement allows mapping different requests with same prepared statement but different arguments to execute the same execution plan.
What is a DataSource in JDBC?
Interface DataSource An alternative to the DriverManager facility, a DataSource object is the preferred means of getting a connection. An object that implements the DataSource interface will typically be registered with a naming service based on the JavaTM Naming and Directory (JNDI) API.