org.mmbase.storage.search.implementation.database

Class InformixSqlHandler

java.lang.Object

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

org.mmbase.storage.search.implementation.database.InformixSqlHandler

All Implemented Interfaces:

SqlHandler

public class InformixSqlHandler
extends BasicSqlHandler
implements SqlHandler

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

• toSql(), implements FEATURE_MAX_NUMBER, by adding a construct like "SELECT FIRST 20" in front of the body, when appropriate.
• getSupportLevel(int,SearchQuery), returns SUPPORT_OPTIMAL for this feature, delegates to the superclass for other features.

Since:

MMBase-1.7

Version:

$Id$

Author:

Rob van Maris

Field Summary

Fields

Modifier and Type	Field and Description
static String	ADD_ORDERED

Constructor Summary

Constructors

Constructor and Description
InformixSqlHandler() Constructor.

Method Summary

Modifier and Type	Method and Description
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 void	closeConnection(Connection con, Statement stmt) Safely close a database connection and/or a database statement.
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.

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

appendCompositeConstraintToSql, appendConstraintToSql, appendDateField, appendDateValue, appendField, appendField, appendField, appendFieldValue, appendLikeOperator, appendLowerField, appendPreField, appendRegularExpressionOperator, appendRelationConstraints, appendSortOrderDirection, appendSortOrderField, appendSortOrderField, appendSortOrders, appendTableAlias, appendTableName, forceEncode, getAllowedValue, getSupportLevel, toSqlString, useLower

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, getAllowedValue, getSupportLevel

Field Detail

ADD_ORDERED

public static final String ADD_ORDERED

See Also:

Constant Field Values

Constructor Detail

InformixSqlHandler

public InformixSqlHandler()

Constructor.

Method Detail

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

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

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

Overrides:

appendQueryBodyToSql in class BasicSqlHandler

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

closeConnection

protected void closeConnection(Connection con,
                               Statement stmt)

Safely close a database connection and/or a database statement.

Parameters:

con - The connection to close. Can be null.

stmt - The statement to close, prior to closing the connection. Can be null.