JDBC – Statement Interface (Handling database queries statically)

The statement interface provides methods that are used to execute static SQL statements. The SQL statements are queries, insertions, updates and deletions, etc.

Some of the methods of the Statement interface are as follows.

• void close(): This method closes database connections associated with Statement’s object and releases JDBC resources.

• boolean execute (String sql): This method is used to execute an SQL statement that might produce multiple result sets or multiple counts. It returns true if multiple result sets are produced and returns false if multiple counts are generated.

• int executeUpdate(String sql): This method is used to execute an SQL statement that gives information about number of affected rows. For example, if we execute the statements like INSERT, DELETE, the result will only be a number of rows affected.

• ResultSet executeQuery(String sql): This method executes a query and returns a Resu1ts et object. A result set isjust like a table containing the resultant data.

• ResultSet getResultSet () : This method returns the first result set or multiple count generated on the execution of execute (String sql) method. If there is no result set, it returns null value.

• int getUpdateCount():After the execution of the execute (String sql) method updates counts may be generated. This method returns the first update count and clears it. More update counts can be retrieved by getMoreResults ().Note that this method returns value -1 if there is no update count or when only result sets are generated on execution of execute (String sql) method.

• boolean getMoreResults () : This method is used to retrieve the next result set in multiple result set or to the next count in multiple update count generated on execution of execute (String sql) method. It returns a true value if multiple sets are available and returns a false value if multiple update counts are available.