org.mmbase.storage.search.implementation.database

Class BasicSqlHandler

java.lang.Object

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

All Implemented Interfaces:

SqlHandler

Direct Known Subclasses:

HSqlSqlHandler, InformixSqlHandler, MSSqlSqlHandler, MySqlSqlHandler, PostgreSqlSqlHandler

public class BasicSqlHandler
extends Object
implements SqlHandler

Basic implementation.

Since:

MMBase-1.7

Version:

$Id$

Author:

Rob van Maris

Constructor Summary

Constructors

Constructor and Description
BasicSqlHandler() Constructor.

Method Summary

Modifier and Type	Method and Description
protected void	appendCompositeConstraintToSql(StringBuilder sb, CompositeConstraint compositeConstraint, SearchQuery query, boolean inverse, boolean inComposite, SqlHandler firstInChain) Represents a CompositeConstraint object as a constraint in SQL format, appending the result to a stringbuffer.
void	appendConstraintToSql(StringBuilder sb, Constraint constraint, SearchQuery query, boolean inverse, boolean inComposite) Represents Constraint object, that is not a CompositeConstraint, as a constraint in SQL format, appending the result to a stringbuffer.
protected void	appendDateField(StringBuilder sb, Step step, String fieldName, boolean multipleSteps, int datePart)
protected void	appendDateValue(StringBuilder sb, Date value)
protected void	appendField(StringBuilder sb, SortOrder sortOrder, boolean includeTablePrefix) Creates an identifier for a field absed on adate from a sortorder, and appends it to a stringbuffer.
protected void	appendField(StringBuilder sb, StepField field, boolean includeTablePrefix)
protected void	appendField(StringBuilder sb, Step step, String fieldName, boolean includeTablePrefix) Creates an identifier for a field, and appends it to a stringbuffer.
void	appendFieldValue(StringBuilder sb, Object value, boolean toLowerCase, int fieldType) Represents field value as a string, appending the result to a stringbuilder
protected StringBuilder	appendLikeOperator(StringBuilder sb, FieldConstraint fieldConstraint) Appends the 'LIKE' operator for the given case sensitiviy.
protected void	appendLowerField(StringBuilder sb, Step step, String fieldName, boolean includeTablePrefix)
protected String	appendPreField(StringBuilder sb, FieldConstraint constraint, StepField field, boolean multiple)
void	appendQueryBodyToSql(StringBuilder sb, SearchQuery query, SqlHandler firstInChain) Represents body of a SearchQuery object as a string in SQL format, using the database configuration.
protected StringBuilder	appendRegularExpressionOperator(StringBuilder sb, FieldConstraint fieldConstraint)
protected void	appendRelationConstraints(StringBuilder sbRelations, RelationStep relationStep, boolean multipleSteps)
protected StringBuilder	appendSortOrderDirection(StringBuilder sb, SortOrder sortOrder)
protected StringBuilder	appendSortOrderField(StringBuilder sb, SortOrder sortOrder, boolean multipleSteps)
protected StringBuilder	appendSortOrderField(StringBuilder sb, SortOrder sortOrder, boolean multipleSteps, SearchQuery query)
protected StringBuilder	appendSortOrders(StringBuilder sb, SearchQuery query)
protected void	appendTableAlias(StringBuilder sb, Step step)
protected void	appendTableName(StringBuilder sb, Step step)
String	forceEncode(String st)
String	getAllowedValue(String value) Maps string to value that is allowed as table or field name.
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.
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 java.lang.Object

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

Constructor Detail

BasicSqlHandler

public BasicSqlHandler()

Constructor.

Method Detail

toSqlString

protected String toSqlString(String str)

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

Parameters:

str - The input string.

Returns:

The modified string.

forceEncode

public String forceEncode(String st)

useLower

protected boolean useLower(FieldConstraint constraint)

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.

appendDateValue

protected void appendDateValue(StringBuilder sb,
                               Date value)

appendFieldValue

public void appendFieldValue(StringBuilder sb,
                             Object value,
                             boolean toLowerCase,
                             int fieldType)

Represents field value as a string, appending the result to a stringbuilder

Depending on the fieldType:

• String values are converted to SQL-formatted string, surrounded by single quotes,
• Numerical values are represented as integer (integral values) or floating point.

Parameters:

sb - The stringbuffer to append to.

value - The field value.

toLowerCase - True when String must be converted to lower case.

fieldType - The field type.

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

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

appendRelationConstraints

protected void appendRelationConstraints(StringBuilder sbRelations,
                                         RelationStep relationStep,
                                         boolean multipleSteps)

Since:

MMBase-1.8

appendQueryBodyToSql

public void appendQueryBodyToSql(StringBuilder sb,
                                 SearchQuery query,
                                 SqlHandler firstInChain)
                          throws SearchQueryException

Description copied from interface: SqlHandler

Represents body of a SearchQuery object as a string in SQL format, using the database configuration. Appends this to a stringbuffer.
The body of the SQL query string is defined as the substring containing fields, tables, constraints and orders.

Specified by:

appendQueryBodyToSql in interface SqlHandler

Parameters:

sb - The stringbuffer to append to.

query - The searchquery.

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

Throws:

SearchQueryException

appendTableName

protected void appendTableName(StringBuilder sb,
                               Step step)

Parameters:

sb -

step -

Since:

MMBase-1.8

appendTableAlias

protected void appendTableAlias(StringBuilder sb,
                                Step step)

Since:

MMBase-1.8

appendSortOrderDirection

protected StringBuilder appendSortOrderDirection(StringBuilder sb,
                                                 SortOrder sortOrder)
                                          throws IllegalStateException

Throws:

IllegalStateException

Since:

MMBase-1.8

appendSortOrderField

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

Since:

MMBase-1.8

appendSortOrderField

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

Since:

MMBase-1.8.2

appendSortOrders

protected StringBuilder appendSortOrders(StringBuilder sb,
                                         SearchQuery query)

Since:

MMBase-1.8

appendLikeOperator

protected StringBuilder appendLikeOperator(StringBuilder sb,
                                           FieldConstraint fieldConstraint)

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.

Returns:

The string buffer.

appendRegularExpressionOperator

protected StringBuilder appendRegularExpressionOperator(StringBuilder sb,
                                                        FieldConstraint fieldConstraint)

appendDateField

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

Javadoc:

appendPreField

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

Since:

MMBase-1.9.2

appendConstraintToSql

public void appendConstraintToSql(StringBuilder sb,
                                  Constraint constraint,
                                  SearchQuery query,
                                  boolean inverse,
                                  boolean inComposite)
                           throws SearchQueryException

Description copied from interface: SqlHandler

Represents Constraint object, that is not a CompositeConstraint, as a constraint in SQL format, appending the result to a stringbuffer. When it is part of a composite expression, it will be surrounded by parenthesis when needed.

Specified by:

appendConstraintToSql in interface SqlHandler

Parameters:

sb - The stringbuffer to append to.

constraint - The (non-composite) constraint.

query - The searchquery containing the constraint.

inverse - True when the inverse constraint must be represented, false otherwise.

inComposite - True when the constraint is part of a composite expression.

Throws:

SearchQueryException

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

Throws:

SearchQueryException

getSupportLevel

public int getSupportLevel(Constraint constraint,
                           SearchQuery query)
                    throws SearchQueryException

Description copied from interface: SqlHandler

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.

Specified by:

getSupportLevel in interface SqlHandler

Throws:

SearchQueryException

getAllowedValue

public String getAllowedValue(String value)

Description copied from interface: SqlHandler

Maps string to value that is allowed as table or field name.

Specified by:

getAllowedValue in interface SqlHandler

Parameters:

value - The string value.

Returns:

The mapped value.

appendCompositeConstraintToSql

protected void appendCompositeConstraintToSql(StringBuilder sb,
                                              CompositeConstraint compositeConstraint,
                                              SearchQuery query,
                                              boolean inverse,
                                              boolean inComposite,
                                              SqlHandler firstInChain)
                                       throws SearchQueryException

Represents a CompositeConstraint object as a constraint in SQL format, appending the result to a stringbuffer. When it is part of a composite expression, it will be surrounded by parenthesis when needed.

Parameters:

sb - The stringbuffer to append to.

compositeConstraint - The composite constraint.

query - The searchquery containing the constraint.

inverse - True when the inverse constraint must be represented, false otherwise.

inComposite - True when the constraint is part of a composite expression.

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

Throws:

SearchQueryException

appendField

protected void appendField(StringBuilder sb,
                           SortOrder sortOrder,
                           boolean includeTablePrefix)

Creates an identifier for a field absed on adate from a sortorder, and appends it to a stringbuffer. The identifier is constructed from the fieldname, optionally prefixed by the tablename or the tablealias - when available.

Parameters:

sb - The stringbuffer to append to.

sortOrder - The sortOrder object containing the field data.

includeTablePrefix - true when the fieldname must be prefixed with the tablename or tablealias (e.g. like in "images.number"), false otherwise.

appendField

protected void appendField(StringBuilder sb,
                           StepField field,
                           boolean includeTablePrefix)

Since:

MMBase-1.9.1

appendField

protected void appendField(StringBuilder sb,
                           Step step,
                           String fieldName,
                           boolean includeTablePrefix)

Creates an identifier for a field, and appends it to a stringbuffer. The identifier is constructed from the fieldname, optionally prefixed by the tablename or the tablealias - when available.

Parameters:

sb - The stringbuffer to append to.

step - The Step the field belongs to.

fieldName - The fields fieldname.

includeTablePrefix - true when the fieldname must be prefixed with the tablename or tablealias (e.g. like in "images.number"), false otherwise.

appendLowerField

protected void appendLowerField(StringBuilder sb,
                                Step step,
                                String fieldName,
                                boolean includeTablePrefix)

Since:

MMBase-1.8.5