Java Articles - Page 246 of 440

In this article, we will learn how to check whether a database supports the SQL GROUP BY clause using JDBC in Java. The GROUP BY clause is used to organize identical data into groups in SQL queries, typically following the WHERE clause and preceding the ORDER BY clause. With JDBC, we can determine whether the underlying database supports this clause using the supportsGroupBy() method of the DatabaseMetaData interface. Problem StatementGiven a MySQL database, write a Java program that connects to the database and checks if the database supports the SQL GROUP BY clause.Input Database connection URL, username, and ... Read More

While creating a Statement object you can choose the concurrency and the type of the ResultSet object using the following variant of the createStatement() method −Statement createStatement(int resultSetType, int resultSetConcurrency)ResultSet ConcurrencyThe concurrency of the ResultSet object determines whether its contents can be updated or not.The ResultSet interface provides two values to specify the concurrency namely −CONCUR_READ_ONLY: If you set this as a value of the concurrency while creating the ResultSet object you cannot update the contents of the ResultSet you can only read/retrieve them.CONCUR_UPDATABLE: If you set this as a value of the concurrency while creating the ResultSet object you ... Read More

While creating a Statement object you can choose the concurrency and the type of the ResultSet object using the following variant of the createStatement() method −Statement createStatement(int resultSetType, int resultSetConcurrency)ResultSet ConcurrencyThe concurrency of the ResultSet object determines whether its contents can be updated or not.The ResultSet interface provides two values to specify the concurrency namely −CONCUR_READ_ONLY: If you set this as a value of the concurrency while creating the ResultSet object you cannot update the contents of the ResultSet you can only read/retrieve them.CONCUR_UPDATABLE: If you set this as a value of the concurrency while creating the ResultSet object you can update ... Read More

JDBC provides support 5 transaction isolation levels through Connection interface.TRANSACTION_NONE: It is represented by integer value 0 does not support transactions.TRANSACTION_READ_COMMITTED: It is represented by integer value 2 supports transactions allowing Non-Repeatable Reads and, Phantom Reads.TRANSACTION_READ_UNCOMMITTED: It is represented by integer value 1 supports transactions allowing Dirty Reads, Non-Repeatable Reads and, Phantom Reads.TRANSACTION_REPEATABLE_READ: It is represented by integer value 4 supports transactions allowing only Phantom Reads.TRANSACTION_SERIALIZABLE: It is represented by integer value 8 supports transactions with out allowing Dirty Reads, Non-Repeatable Reads and, Phantom Reads.Following JDBC example displays all the transactions levels provided by the Connection interface of the JDBC ... Read More

JDBC provides support 5 transaction isolation levels through Connection interface.TRANSACTION_NONE: It is represented by integer value 0 does not support transactions.TRANSACTION_READ_COMMITTED: It is represented by integer value 2 supports transactions allowing Non-Repeatable Reads and, Phantom Reads.TRANSACTION_READ_UNCOMMITTED: It is represented by integer value 1 supports transactions allowing Dirty Reads, Non-Repeatable Reads and, Phantom Reads.TRANSACTION_REPEATABLE_READ: It is represented by integer value 4 supports transactions allowing only Phantom Reads.TRANSACTION_SERIALIZABLE: It is represented by integer value 8 supports transactions with out allowing Dirty Reads, Non-Repeatable Reads and, Phantom Reads.The supportsTransactionIsolationLevel() method of the DatabaseMetaData interface is used to determine whether the underlying database supports ... Read More

The supportsTransactions() method of the DatabaseMetaData interface is used to determine whether the underlying database supports transactions.This method returns a boolean value which is −True, when the underlying database supports stored procedures.False, when the underlying database doesn't support stored procedures.To determine whether the underlying database supports stored procedures−Make sure your database is up and running.Register the driver using the registerDriver() method of the DriverManager class. Pass an object of the driver class corresponding to the underlying database.Get the connection object using the getConnection() method of the DriverManager class. Pass the URL the database and, user name, password of a user ... Read More

The supportsBatchUpdates() method of the DatabaseMetaData interface is used to determine whether the underlying database supports batch updates.This method returns a boolean value which is −True, when the underlying database supports stored porcedures.False, when the underlying database doesn't support stored porcedures.To determine whether the underlying database supports stored porcedures −Make sure your database is up and running.Register the driver using the registerDriver() method of the DriverManager class. Pass an object of the driver class corresponding to the underlying database.Get the connection object using the getConnection() method of the DriverManager class. Pass the URL the database and, user name, password of ... Read More

The supportsStoredProcedures() method of the DatabaseMetaData interface is used to determine whether the underlying database supports stored procedures.This method returns a boolean value which is −True, when the underlying database supports stored procedures.False, when the underlying database doesn't support stored procedures.To determine whether the underlying database supports stored procedures−Make sure your database is up and running.Register the driver using the registerDriver() method of the DriverManager class. Pass an object of the driver class corresponding to the underlying database.Get the connection object using the getConnection() method of the DriverManager class. Pass the URL the database and, user name, password of a ... Read More

The supportsSavepoints() method of the DatabaseMetaData interface is used to determine whether the underlying database supports savepoints.This method returns a boolean value which is −True, when the underlying database supports savepoints.False, when the underlying database doesn't support savepoints.To determine whether the underlying database supports save points −Make sure your database is up and running.Register the driver using the registerDriver() method of the DriverManager class. Pass an object of the driver class corresponding to the underlying database.Get the connection object using the getConnection() method of the DriverManager class. Pass the URL the database and, user name, password of a user in the ... Read More

The is AutoIncrement() method of the ResultSetMetaData (interface) determines whether a particular column in the current ResultSet object is automatically numbered.This method accepts an integer value representing the index of a column and, returns a boolean value which is −True, if the specified column is automatically numbered.False, if the specified column is not automatically numbered.To get the ResultSetMetaData object, you need to −Register the Driver: Select the required database register the Driver class of the particular database using the registerDriver() method of the DriverManager class or, the forName() method of the class named Class.DriverManager.registerDriver(new com.mysql.jdbc.Driver());Get connection: Create a connection object by ... Read More