mondrian.spi.impl

Class InformixDialect

java.lang.Object

mondrian.spi.impl.JdbcDialectImpl

mondrian.spi.impl.InformixDialect

All Implemented Interfaces:

Dialect

public class InformixDialect
extends JdbcDialectImpl

Implementation of Dialect for the Informix database.

Since:

Nov 23, 2008

Author:

jhyde

Nested Class Summary

Nested classes/interfaces inherited from interface mondrian.spi.Dialect

Dialect.DatabaseProduct, Dialect.Datatype

Field Summary

Fields

Modifier and Type	Field and Description
static JdbcDialectFactory	FACTORY

Fields inherited from class mondrian.spi.impl.JdbcDialectImpl

databaseProduct, permitsSelectNotInGroupBy, productVersion

Constructor Summary

Constructors

Constructor and Description
InformixDialect(Connection connection) Creates an InformixDialect.

Method Summary

Modifier and Type	Method and Description
boolean	allowsFromQuery() Returns whether this Dialect allows a subquery in the from clause, for example SELECT * FROM (SELECT * FROM t) AS x
String	generateOrderByNulls(String expr, boolean ascending, boolean collateNullsLast) Generates SQL to force null values to collate last.
boolean	supportsGroupByExpressions() Returns whether this Dialect supports expressions in the GROUP BY clause.

Methods inherited from class mondrian.spi.impl.JdbcDialectImpl

allowsAs, allowsCompoundCountDistinct, allowsCountDistinct, allowsCountDistinctWithOtherAggs, allowsDdl, allowsDialectSharing, allowsJoinOn, allowsMultipleCountDistinct, allowsMultipleDistinctSqlMeasures, allowsOrderByAlias, allowsRegularExpressionInWhereClause, allowsSelectNotInGroupBy, appendHintsAfterFromClause, caseWhenElse, computeStatisticsProviders, deduceIdentifierQuoteString, deduceMaxColumnNameLength, deduceProductName, deduceProductVersion, deduceReadOnly, deduceSupportedResultSetStyles, deduceSupportsSelectNotInGroupBy, generateCountExpression, generateInline, generateInlineForAnsi, generateInlineGeneric, generateOrderByNullsAnsi, generateOrderItem, generateRegularExpression, getDatabaseProduct, getMaxColumnNameLength, getProduct, getQuoteIdentifierString, getStatisticsProviders, getType, isDatabase, needsExponent, quote, quoteBooleanLiteral, quoteDateLiteral, quoteDateLiteral, quoteIdentifier, quoteIdentifier, quoteIdentifier, quoteIdentifier, quoteNumericLiteral, quoteStringLiteral, quoteTimeLiteral, quoteTimestampLiteral, requiresAliasForFromQuery, requiresGroupByAlias, requiresHavingAlias, requiresOrderByAlias, requiresUnionOrderByExprToBeInSelectClause, requiresUnionOrderByOrdinal, supportsGroupingSets, supportsMultiValueInExpr, supportsResultSetConcurrency, supportsUnlimitedValueList, toString, toUpper

Methods inherited from class java.lang.Object

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

Field Detail

FACTORY

public static final JdbcDialectFactory FACTORY

Constructor Detail

InformixDialect

public InformixDialect(Connection connection)
                throws SQLException

Creates an InformixDialect.

Parameters:

connection - Connection

Throws:

SQLException

Method Detail

allowsFromQuery

public boolean allowsFromQuery()

Description copied from interface: Dialect

Returns whether this Dialect allows a subquery in the from clause, for example

SELECT * FROM (SELECT * FROM t) AS x

Specified by:

allowsFromQuery in interface Dialect

Overrides:

allowsFromQuery in class JdbcDialectImpl

Returns:

whether Dialect allows subquery in FROM clause

See Also:

Dialect.requiresAliasForFromQuery()

generateOrderByNulls

public String generateOrderByNulls(String expr,
                                   boolean ascending,
                                   boolean collateNullsLast)

Description copied from class: JdbcDialectImpl

Generates SQL to force null values to collate last.

This default implementation makes use of the ANSI SQL 1999 CASE-WHEN-THEN-ELSE in conjunction with IS NULL syntax. The resulting SQL will look something like this:

CASE WHEN "expr" IS NULL THEN 0 ELSE 1 END

You can override this method for a particular database to use something more efficient, like ISNULL().

ANSI SQL provides the syntax "ASC/DESC NULLS LAST" and "ASC/DESC NULLS FIRST". If your database supports the ANSI syntax, implement this method by calling JdbcDialectImpl.generateOrderByNullsAnsi(java.lang.String, boolean, boolean).

This method is only called from JdbcDialectImpl.generateOrderItem(String, boolean, boolean, boolean). Some dialects override that method and therefore never call this method.

Overrides:

generateOrderByNulls in class JdbcDialectImpl

Parameters:

expr - Expression.

ascending - Whether ascending.

collateNullsLast - Whether nulls should appear first or last.

Returns:

Expression to force null values to collate last or first.

supportsGroupByExpressions

public boolean supportsGroupByExpressions()

Description copied from interface: Dialect

Returns whether this Dialect supports expressions in the GROUP BY clause. Derby/Cloudscape and Infobright do not.

Specified by:

supportsGroupByExpressions in interface Dialect

Overrides:

supportsGroupByExpressions in class JdbcDialectImpl

Returns:

Whether this Dialect allows expressions in the GROUP BY clause