Interface QueryDelegate

Method Detail

• getCount

  int getCount()
        throws SQLException

  Generates and executes a query to determine the current row count from the DB. Row count will be fetched using filters that are currently set to the QueryDelegate.

  Returns:

  row count

  Throws:

  SQLException

• getResults

  ResultSet getResults(int offset,
                       int pagelength)
                throws SQLException

  Executes a paged SQL query and returns the ResultSet. The query is defined through implementations of this QueryDelegate interface.

  Parameters:

  offset - the first item of the page to load

  pagelength - the length of the page to load

  Returns:

  a ResultSet containing the rows of the page

  Throws:

  SQLException - if the database access fails.

• implementationRespectsPagingLimits

  boolean implementationRespectsPagingLimits()

  Allows the SQLContainer implementation to check whether the QueryDelegate implementation implements paging in the getResults method.

  Returns:

  true if the delegate implements paging

  See Also:

  getResults(int, int)

• setFilters

  void setFilters(List<Container.Filter> filters)
           throws UnsupportedOperationException

  Sets the filters to apply when performing the SQL query. These are translated into a WHERE clause. Default filtering mode will be used.

  Parameters:

  filters - The filters to apply.

  Throws:

  UnsupportedOperationException - if the implementation doesn't support filtering.

• setOrderBy

  void setOrderBy(List<OrderBy> orderBys)
           throws UnsupportedOperationException

  Sets the order in which to retrieve rows from the database. The result can be ordered by zero or more columns and each column can be in ascending or descending order. These are translated into an ORDER BY clause in the SQL query.

  Parameters:

  orderBys - A list of the OrderBy conditions.

  Throws:

  UnsupportedOperationException - if the implementation doesn't support ordering.

• storeRow

  int storeRow(RowItem row)
        throws UnsupportedOperationException,
               SQLException

  Stores a row in the database. The implementation of this interface decides how to identify whether to store a new row or update an existing one.

  Parameters:

  columnToValueMap - A map containing the values for all columns to be stored or updated.

  Returns:

  the number of affected rows in the database table

  Throws:

  UnsupportedOperationException - if the implementation is read only.

  SQLException

• removeRow

  boolean removeRow(RowItem row)
             throws UnsupportedOperationException,
                    SQLException

  Removes the given RowItem from the database.

  Parameters:

  row - RowItem to be removed

  Returns:

  true on success

  Throws:

  UnsupportedOperationException

  SQLException

• beginTransaction

  void beginTransaction()
                 throws SQLException

  Starts a new database transaction. Used when storing multiple changes. Note that if a transaction is already open, it will be rolled back when a new transaction is started.

  Throws:

  SQLException - if the database access fails.

• commit

  void commit()
       throws SQLException

  Commits a transaction. If a transaction is not open nothing should happen.

  Throws:

  SQLException - if the database access fails.

• rollback

  void rollback()
         throws SQLException

  Rolls a transaction back. If a transaction is not open nothing should happen.

  Throws:

  SQLException - if the database access fails.

• getPrimaryKeyColumns

  List<String> getPrimaryKeyColumns()

  Returns a list of primary key column names. The list is either fetched from the database (TableQuery) or given as an argument depending on implementation.

  Returns:

• containsRowWithKey

  boolean containsRowWithKey(Object... keys)
                      throws SQLException

  Performs a query to find out whether the SQL table contains a row with the given set of primary keys.

  Parameters:

  keys - the primary keys

  Returns:

  true if the SQL table contains a row with the provided keys

  Throws:

  SQLException