com.vaadin.data.util.sqlcontainer.query

Interface FreeformStatementDelegate

All Superinterfaces:

FreeformQueryDelegate, Serializable

public interface FreeformStatementDelegate
extends FreeformQueryDelegate

FreeformStatementDelegate is an extension to FreeformQueryDelegate that provides definitions for methods that produce StatementHelper objects instead of basic query strings. This allows the FreeformQuery query delegate to use PreparedStatements instead of regular Statement when accessing the database. Due to the injection protection and other benefits of prepared statements, it is advisable to implement this interface instead of the FreeformQueryDelegate whenever possible.

Method Summary

Modifier and Type	Method and Description
StatementHelper	getContainsRowQueryStatement(Object... keys) Should return a new instance of StatementHelper that contains the query string and parameter values required to create a PreparedStatement used by the FreeformQuery.containsRowWithKeys() method.
StatementHelper	getCountStatement() Should return a new instance of StatementHelper that contains the query string and parameter values required to create a PreparedStatement that will fetch the row count from the DB.
StatementHelper	getQueryStatement(int offset, int limit) Should return a new instance of StatementHelper that contains the query string and parameter values required to create a PreparedStatement.

Methods inherited from interface com.vaadin.data.util.sqlcontainer.query.FreeformQueryDelegate

getContainsRowQueryString, getCountQuery, getQueryString, removeRow, setFilters, setOrderBy, storeRow

Method Detail

getQueryStatement

StatementHelper getQueryStatement(int offset,
                                  int limit)
                           throws UnsupportedOperationException

Should return a new instance of StatementHelper that contains the query string and parameter values required to create a PreparedStatement. This method is responsible for gluing together the select query from the filters and the order by conditions if these are supported.

Parameters:

offset - the first record (row) to fetch.

pagelength - the number of records (rows) to fetch. 0 means all records starting from offset.

Throws:

UnsupportedOperationException

getCountStatement

StatementHelper getCountStatement()
                           throws UnsupportedOperationException

Should return a new instance of StatementHelper that contains the query string and parameter values required to create a PreparedStatement that will fetch the row count from the DB. Row count should be fetched using filters that are currently set to the QueryDelegate.

Throws:

UnsupportedOperationException

getContainsRowQueryStatement

StatementHelper getContainsRowQueryStatement(Object... keys)
                                      throws UnsupportedOperationException

Should return a new instance of StatementHelper that contains the query string and parameter values required to create a PreparedStatement used by the FreeformQuery.containsRowWithKeys() method. This is useful for cases when the default logic in said method is not enough to support more complex free form queries.

Parameters:

keys - the values of the primary keys

Throws:

UnsupportedOperationException - to use the default logic in FreeformQuery