org.mmbase.storage.search.implementation.database

Class MySqlSqlHandler

java.lang.Object

org.mmbase.storage.search.implementation.database.BasicSqlHandler

org.mmbase.storage.search.implementation.database.MySqlSqlHandler

All Implemented Interfaces:

SqlHandler

public class MySqlSqlHandler
extends BasicSqlHandler
implements SqlHandler

The MySQL query handler, implements SqlHandler for standard MySQL functionality.
Derived from BasicSqlHandler, overrides

• toSql(), implements FEATURE_MAX_NUMBER and FEATURE_OFFSET, by adding a construct like "LIMIT 20" or "LIMIT 80, 20" after the body, when appropriate.
• getSupportLevel(int,SearchQuery), returns SUPPORT_OPTIMAL for these features, delegates to the superclass for other features.

Since:

MMBase-1.7

Version:

$Id$

Author:

Rob van Maris

Constructor Summary

Constructors

Constructor and Description
MySqlSqlHandler() Constructor.

Method Summary

Modifier and Type	Method and Description
protected void	appendDateField(StringBuilder sb, Step step, String fieldName, boolean multipleSteps, int datePart)
protected StringBuilder	appendLikeOperator(StringBuilder sb, FieldConstraint constraint) Appends the 'LIKE' operator for the given case sensitiviy.
protected String	appendPreField(StringBuilder sb, FieldConstraint constraint, StepField field, boolean multiple)
protected StringBuilder	appendRegularExpressionOperator(StringBuilder sb, FieldConstraint constraint)
protected StringBuilder	appendSortOrderField(StringBuilder sb, SortOrder sortOrder, boolean multipleSteps)
protected DataType	getDataType(StepField field)
protected CoreField	getField(StepField field)
int	getSupportLevel(int feature, SearchQuery query) Gets the level at which a feature is supported for a query by this handler.
protected boolean	isCaseSensitive(DataType dt)
String	toSql(SearchQuery query, SqlHandler firstInChain) Represents a SearchQuery object as a string in SQL format, using the database configuration.
protected String	toSqlString(String str) Utility method, modifies strings for use in SQL statements.
protected boolean	useLower(FieldConstraint constraint) Wether the 'LOWER' function needs to be used to implement case insensitivity.

Methods inherited from class org.mmbase.storage.search.implementation.database.BasicSqlHandler

appendCompositeConstraintToSql, appendConstraintToSql, appendDateValue, appendField, appendField, appendField, appendFieldValue, appendLowerField, appendQueryBodyToSql, appendRelationConstraints, appendSortOrderDirection, appendSortOrderField, appendSortOrders, appendTableAlias, appendTableName, forceEncode, getAllowedValue, getSupportLevel

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.mmbase.storage.search.implementation.database.SqlHandler

appendConstraintToSql, appendQueryBodyToSql, getAllowedValue, getSupportLevel

Constructor Detail

MySqlSqlHandler

public MySqlSqlHandler()

Constructor.

Method Detail

toSqlString

protected String toSqlString(String str)

Description copied from class: BasicSqlHandler

Utility method, modifies strings for use in SQL statements. This amounts to replacing all single quotes by two single quotes.

Overrides:

toSqlString in class BasicSqlHandler

Parameters:

str - The input string.

Returns:

The modified string.

getSupportLevel

public int getSupportLevel(int feature,
                           SearchQuery query)
                    throws SearchQueryException

Description copied from interface: SqlHandler

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.

Specified by:

getSupportLevel in interface SqlHandler

Overrides:

getSupportLevel in class BasicSqlHandler

Throws:

SearchQueryException

getField

protected CoreField getField(StepField field)

getDataType

protected DataType getDataType(StepField field)

isCaseSensitive

protected boolean isCaseSensitive(DataType dt)

useLower

protected boolean useLower(FieldConstraint constraint)

Description copied from class: BasicSqlHandler

Wether the 'LOWER' function needs to be used to implement case insensitivity. This is not always the case, because some database only match case insensitively, in which case it does not make sense to lowercase.

Overrides:

useLower in class BasicSqlHandler

appendPreField

protected String appendPreField(StringBuilder sb,
                                FieldConstraint constraint,
                                StepField field,
                                boolean multiple)

Overrides:

appendPreField in class BasicSqlHandler

Since:

MMBase-1.9.2

appendLikeOperator

protected StringBuilder appendLikeOperator(StringBuilder sb,
                                           FieldConstraint constraint)

Description copied from class: BasicSqlHandler

Appends the 'LIKE' operator for the given case sensitiviy. Some databases support a case insensitive LIKE ('ILIKE'). Implementations for those database can override this method.

Overrides:

appendLikeOperator in class BasicSqlHandler

Returns:

The string buffer.

appendRegularExpressionOperator

protected StringBuilder appendRegularExpressionOperator(StringBuilder sb,
                                                        FieldConstraint constraint)

Overrides:

appendRegularExpressionOperator in class BasicSqlHandler

appendDateField

protected void appendDateField(StringBuilder sb,
                               Step step,
                               String fieldName,
                               boolean multipleSteps,
                               int datePart)

Overrides:

appendDateField in class BasicSqlHandler

Javadoc:

appendSortOrderField

protected StringBuilder appendSortOrderField(StringBuilder sb,
                                             SortOrder sortOrder,
                                             boolean multipleSteps)

Overrides:

appendSortOrderField in class BasicSqlHandler

toSql

public String toSql(SearchQuery query,
                    SqlHandler firstInChain)
             throws SearchQueryException

Description copied from interface: SqlHandler

Represents a SearchQuery object as a string in SQL format, using the database configuration.

Specified by:

toSql in interface SqlHandler

Overrides:

toSql in class BasicSqlHandler

Parameters:

query - The searchquery.

firstInChain - The first element in the chain of handlers. At some point appendQueryBodyToSql() will have to be called on this handler, to generate the body of the query.

Returns:

SQL string representation of the query.

Throws:

SearchQueryException