org.mmbase.storage.search
Interface SearchQueryHandler

public interface SearchQueryHandler

Defines methods for an object that handles search query requests.

Since:

MMBase-1.7

Version:

$Id: SearchQueryHandler.java 42911 2010-07-15 14:56:15Z michiel $

Author:

Rob van Maris

Field Summary

static int	FEATURE_MAX_NUMBER Feature that allows specifying the maximum number of results to be returned.
static int	FEATURE_OFFSET Feature that allows specifying an index in the list of results, as a starting popublic final static int for results to be returned.
static int	FEATURE_REGEXP Feature that allows to search on string by a regular expression.
static int	SUPPORT_NONE Support level for features that are not supported.
static int	SUPPORT_NORMAL Support level for features that are available for use under normal circumstances.
static int	SUPPORT_OPTIMAL Support level for features that are optimally supported.
static int	SUPPORT_WEAK Support level for features that are supported, but not recommended when performance is critical.

Method Summary

String	createSqlString(SearchQuery query) Makes a String of a query, taking into consideration if the database supports offset and maxnumber features.
int	getSupportLevel(Constraint constraint, SearchQuery query) Gets the level at which a constraint is supported for a query by this handler.
int	getSupportLevel(int feature, SearchQuery query) Gets the level at which a feature is supported for a query by this handler.

Field Detail

SUPPORT_NONE

static final int SUPPORT_NONE

Support level for features that are not supported.

See Also:

Constant Field Values

SUPPORT_WEAK

static final int SUPPORT_WEAK

Support level for features that are supported, but not recommended when performance is critical.

See Also:

Constant Field Values

SUPPORT_NORMAL

static final int SUPPORT_NORMAL

Support level for features that are available for use under normal circumstances.

See Also:

Constant Field Values

SUPPORT_OPTIMAL

static final int SUPPORT_OPTIMAL

Support level for features that are optimally supported. This applies also to features that are supported without a significant impact on performance penalty.

See Also:

Constant Field Values

FEATURE_MAX_NUMBER

static final int FEATURE_MAX_NUMBER

Feature that allows specifying the maximum number of results to be returned.

See Also:

SearchQuery.getMaxNumber(), Constant Field Values

FEATURE_OFFSET

static final int FEATURE_OFFSET

Feature that allows specifying an index in the list of results, as a starting popublic final static int for results to be returned.

See Also:

SearchQuery.getOffset(), Constant Field Values

FEATURE_REGEXP

static final int FEATURE_REGEXP

Feature that allows to search on string by a regular expression.

See Also:

SearchQuery.getOffset(), Constant Field Values

Method Detail

getSupportLevel

int getSupportLevel(int feature,
                    SearchQuery query)
                    throws SearchQueryException

Gets the level at which a feature is supported for a query by this handler. This is one of either:

• SUPPORT_NONE
• SUPPORT_WEAK
• SUPPORT_NORMAL
• SUPPORT_OPTIMAL

Given the choice, the query handler with the highest level of support is prefered.

Throws:

SearchQueryException

getSupportLevel

int getSupportLevel(Constraint constraint,
                    SearchQuery query)
                    throws SearchQueryException

Gets the level at which a constraint is supported for a query by this handler. This is one of either:

• SUPPORT_NONE
• SUPPORT_WEAK
• SUPPORT_NORMAL
• SUPPORT_OPTIMAL

Given the choice, the query handler with the highest level of support is prefered.

Throws:

SearchQueryException

createSqlString

String createSqlString(SearchQuery query)
                       throws SearchQueryException

Makes a String of a query, taking into consideration if the database supports offset and maxnumber features. The resulting String is an SQL query which can be fed to the database.

Parameters:

query - the query to convert to sql

Returns:

the sql string

Throws:

SearchQueryException - when error occurs while making the string

Since:

MMBase-1.8.5