mondrian.spi.impl

Class SnowflakeDialect

java.lang.Object

mondrian.spi.impl.JdbcDialectImpl

mondrian.spi.impl.SnowflakeDialect

All Implemented Interfaces:

Dialect

public class SnowflakeDialect
extends JdbcDialectImpl

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	SnowflakeDialect.RegexParameters

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
SnowflakeDialect(Connection connection)

Method Summary

Modifier and Type	Method and Description
boolean	allowsOrderByAlias() Returns true if aliases defined in the SELECT clause can be used as expressions in the ORDER BY clause.
boolean	allowsRegularExpressionInWhereClause() Informs Mondrian if the dialect supports regular expressions when creating the 'where' or the 'having' clause.
boolean	allowsSelectNotInGroupBy() Returns whether the database currently permits queries to include in the SELECT clause expressions that are not listed in the GROUP BY clause.
String	generateInline(List<String> columnNames, List<String> columnTypes, List<String[]> valueList) Generates a SQL statement to represent an inline dataset.
String	generateRegularExpression(String source, String javaRegex) Must generate a String representing a regular expression match operation between a string literal and a Java regular expression.
String	getQuoteIdentifierString() Returns the character which is used to quote identifiers, or null if quoting is not supported.
void	quoteStringLiteral(StringBuilder buf, String s) Appends to a buffer a single-quoted SQL string.
boolean	requiresOrderByAlias() Requires order by alias, in some cases: For example: a select query that lists all the columns used in the ORDER_BY expression will succeed SELECT "store_id", "unit_sales" FROM "sales_fact_1997" ORDER BY "store_id" + "unit_sales"; while a query that only has some of the columns used in the ORDER_BY expression will not: SELECT "unit_sales" FROM "sales_fact_1997" ORDER BY "store_id" + "unit_sales";

Methods inherited from class mondrian.spi.impl.JdbcDialectImpl

allowsAs, allowsCompoundCountDistinct, allowsCountDistinct, allowsCountDistinctWithOtherAggs, allowsDdl, allowsDialectSharing, allowsFromQuery, allowsJoinOn, allowsMultipleCountDistinct, allowsMultipleDistinctSqlMeasures, appendHintsAfterFromClause, caseWhenElse, computeStatisticsProviders, deduceIdentifierQuoteString, deduceMaxColumnNameLength, deduceProductName, deduceProductVersion, deduceReadOnly, deduceSupportedResultSetStyles, deduceSupportsSelectNotInGroupBy, generateCountExpression, generateInlineForAnsi, generateInlineGeneric, generateOrderByNulls, generateOrderByNullsAnsi, generateOrderItem, getDatabaseProduct, getMaxColumnNameLength, getProduct, getStatisticsProviders, getType, isDatabase, needsExponent, quote, quoteBooleanLiteral, quoteDateLiteral, quoteDateLiteral, quoteIdentifier, quoteIdentifier, quoteIdentifier, quoteIdentifier, quoteNumericLiteral, quoteTimeLiteral, quoteTimestampLiteral, quoteTimestampLiteral, requiresAliasForFromQuery, requiresGroupByAlias, requiresHavingAlias, requiresUnionOrderByExprToBeInSelectClause, requiresUnionOrderByOrdinal, supportsGroupByExpressions, 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

SnowflakeDialect

public SnowflakeDialect(Connection connection)
                 throws SQLException

Throws:

SQLException

Method Detail

getQuoteIdentifierString

public String getQuoteIdentifierString()

Description copied from interface: Dialect

Returns the character which is used to quote identifiers, or null if quoting is not supported.

Specified by:

getQuoteIdentifierString in interface Dialect

Overrides:

getQuoteIdentifierString in class JdbcDialectImpl

Returns:

identifier quote

generateInline

public String generateInline(List<String> columnNames,
                             List<String> columnTypes,
                             List<String[]> valueList)

Description copied from interface: Dialect

Generates a SQL statement to represent an inline dataset.

For example, for Oracle, generates

 SELECT 1 AS FOO, 'a' AS BAR FROM dual
 UNION ALL
 SELECT 2 AS FOO, 'b' AS BAR FROM dual
 

For ANSI SQL, generates:

 VALUES (1, 'a'), (2, 'b')
 

Specified by:

generateInline in interface Dialect

Overrides:

generateInline in class JdbcDialectImpl

Parameters:

columnNames - List of column names

columnTypes - List of column types ("String" or "Numeric")

valueList - List of rows values

Returns:

SQL string

quoteStringLiteral

public void quoteStringLiteral(StringBuilder buf,
                               String s)

Description copied from interface: Dialect

Appends to a buffer a single-quoted SQL string.

For example, in the default dialect, quoteStringLiteral(buf, "Can't") appends "'Can''t'" to buf.

Specified by:

quoteStringLiteral in interface Dialect

Overrides:

quoteStringLiteral in class JdbcDialectImpl

Parameters:

buf - Buffer to append to

s - Literal

allowsOrderByAlias

public boolean allowsOrderByAlias()

Description copied from interface: Dialect

Returns true if aliases defined in the SELECT clause can be used as expressions in the ORDER BY clause.

For example, in such a dialect,

SELECT x, x + y AS z FROM t ORDER BY z

would be legal.

MySQL, DB2 and Ingres are examples of dialects where this is true; Access is a dialect where this is false.

Specified by:

allowsOrderByAlias in interface Dialect

Overrides:

allowsOrderByAlias in class JdbcDialectImpl

Returns:

Whether aliases defined in the SELECT clause can be used as expressions in the ORDER BY clause.

allowsSelectNotInGroupBy

public boolean allowsSelectNotInGroupBy()

Description copied from interface: Dialect

Returns whether the database currently permits queries to include in the SELECT clause expressions that are not listed in the GROUP BY clause. The SQL standard allows this if the database can deduce that the expression is functionally dependent on columns in the GROUP BY clause.

For example, SELECT empno, first_name || ' ' || last_name FROM emps GROUP BY empno is valid because empno is the primary key of the emps table, and therefore all columns are dependent on it. For a given value of empno, first_name || ' ' || last_name has a unique value.

Most databases do not, MySQL is an example of one that does (if the functioality is enabled).

Specified by:

allowsSelectNotInGroupBy in interface Dialect

Overrides:

allowsSelectNotInGroupBy in class JdbcDialectImpl

Returns:

Whether this Dialect allows SELECT clauses to contain columns that are not in the GROUP BY clause

requiresOrderByAlias

public boolean requiresOrderByAlias()

Requires order by alias, in some cases: For example: a select query that lists all the columns used in the ORDER_BY expression will succeed SELECT "store_id", "unit_sales" FROM "sales_fact_1997" ORDER BY "store_id" + "unit_sales"; while a query that only has some of the columns used in the ORDER_BY expression will not: SELECT "unit_sales" FROM "sales_fact_1997" ORDER BY "store_id" + "unit_sales";

Specified by:

requiresOrderByAlias in interface Dialect

Overrides:

requiresOrderByAlias in class JdbcDialectImpl

Returns:

true, in some cases snowflake requires expressions in the ORDER_BY clause to be in aliased in the SELECT clause

allowsRegularExpressionInWhereClause

public boolean allowsRegularExpressionInWhereClause()

Description copied from interface: Dialect

Informs Mondrian if the dialect supports regular expressions when creating the 'where' or the 'having' clause.

Specified by:

allowsRegularExpressionInWhereClause in interface Dialect

Overrides:

allowsRegularExpressionInWhereClause in class JdbcDialectImpl

Returns:

True if regular expressions are supported.

generateRegularExpression

public String generateRegularExpression(String source,
                                        String javaRegex)

Description copied from interface: Dialect

Must generate a String representing a regular expression match operation between a string literal and a Java regular expression. The string literal might be a column identifier or some other identifier, but the implementation must presume that it is already escaped and fit for use. The regular expression is not escaped and must be adapted to the proper dialect rules.

Postgres / Greenplum example:

generateRegularExpression( "'foodmart'.'customer_name'", "(?i).*oo.*") -> 'foodmart'.'customer_name' ~ "(?i).*oo.*"

Oracle example:

generateRegularExpression( "'foodmart'.'customer_name'", ".*oo.*") -> REGEXP_LIKE('foodmart'.'customer_name', ".*oo.*")

Dialects are allowed to return null if the dialect cannot convert that particular regular expression into something that the database would support.

Specified by:

generateRegularExpression in interface Dialect

Overrides:

generateRegularExpression in class JdbcDialectImpl

Parameters:

source - A String identifying the column to match against.

javaRegex - A Java regular expression to match against.

Returns:

A dialect specific matching operation, or null if the dialect cannot convert that particular regular expression into something that the database would support.