de.fuberlin.wiwiss.d2rq.sql.vendor

Class SQLServer

java.lang.Object

de.fuberlin.wiwiss.d2rq.sql.vendor.SQL92

de.fuberlin.wiwiss.d2rq.sql.vendor.SQLServer

All Implemented Interfaces:

Vendor

public class SQLServer
extends SQL92

This syntax class implements SQL syntax for MS SQL Server and MS Access.

Author:

Richard Cyganiak (richard@cyganiak.de)

Field Summary

Fields inherited from interface de.fuberlin.wiwiss.d2rq.sql.vendor.Vendor

HSQLDB, InterbaseOrFirebird, MSAccess, MySQL, Oracle, PostgreSQL, SQL92, SQLServer

Constructor Summary

Constructors

Constructor and Description
SQLServer()

Method Summary

Methods

Modifier and Type	Method and Description
Expression	booleanExpressionToSimpleExpression(Expression expression) Expressions can not return true or false in Microsoft SQL Server.
DataType	getDataType(int jdbcType, String name, int size) Returns a DataType corresponding to a JDBC type.
String	getRowNumLimitAsQueryAppendage(int limit) Technically speaking, SQL 92 supports NO way of limiting result sets (ROW_NUMBER appeared in SQL 2003).
String	getRowNumLimitAsSelectModifier(int limit) Returns a modifier for the SELECT keyword that adds a limit to the number of returned rows for engines that support this (TOP n)
boolean	isIgnoredTable(String schema, String table) TODO Use the Filter interface for this
String	quoteBinaryLiteral(String hexString)
String	quoteDateLiteral(String date)
String	quoteTimeLiteral(String time)
String	quoteTimestampLiteral(String timestamp)

Methods inherited from class de.fuberlin.wiwiss.d2rq.sql.vendor.SQL92

afterCancel, afterClose, afterQuery, beforeCancel, beforeClose, beforeQuery, getConcatenationExpression, getDefaultConnectionProperties, getRelationNameAliasExpression, getRowNumLimitAsExpression, initializeConnection, quoteAttribute, quoteIdentifier, quoteRelationName, quoteStringLiteral

Methods inherited from class java.lang.Object

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

Constructor Detail

SQLServer

public SQLServer()

Method Detail

getRowNumLimitAsSelectModifier

public String getRowNumLimitAsSelectModifier(int limit)

Description copied from interface: Vendor

Returns a modifier for the SELECT keyword that adds a limit to the number of returned rows for engines that support this (TOP n)

Specified by:

getRowNumLimitAsSelectModifier in interface Vendor

Overrides:

getRowNumLimitAsSelectModifier in class SQL92

Parameters:

limit - A maximum number of rows, or Database.NO_LIMIT

Returns:

A SELECT keyword modifier, or the empty string if unsupported/unnecessary

getRowNumLimitAsQueryAppendage

public String getRowNumLimitAsQueryAppendage(int limit)

Description copied from class: SQL92

Technically speaking, SQL 92 supports NO way of limiting result sets (ROW_NUMBER appeared in SQL 2003). We will just use MySQL's LIMIT as it appears to be widely implemented.

Specified by:

getRowNumLimitAsQueryAppendage in interface Vendor

Overrides:

getRowNumLimitAsQueryAppendage in class SQL92

Parameters:

limit - A maximum number of rows, or Database.NO_LIMIT

Returns:

A SQL fragment, or the empty string if unsupported/unnecessary

quoteBinaryLiteral

public String quoteBinaryLiteral(String hexString)

Specified by:

quoteBinaryLiteral in interface Vendor

Overrides:

quoteBinaryLiteral in class SQL92

quoteDateLiteral

public String quoteDateLiteral(String date)

Specified by:

quoteDateLiteral in interface Vendor

Overrides:

quoteDateLiteral in class SQL92

quoteTimeLiteral

public String quoteTimeLiteral(String time)

Specified by:

quoteTimeLiteral in interface Vendor

Overrides:

quoteTimeLiteral in class SQL92

quoteTimestampLiteral

public String quoteTimestampLiteral(String timestamp)

Specified by:

quoteTimestampLiteral in interface Vendor

Overrides:

quoteTimestampLiteral in class SQL92

getDataType

public DataType getDataType(int jdbcType,
                   String name,
                   int size)

Description copied from interface: Vendor

Returns a DataType corresponding to a JDBC type. This may be an unsupported datatype; in this case, its DataType.isUnsupported() method will return true. null will be returned if the vendor code doesn't handle this datatype at all; that should generally be considered a bug.

Specified by:

getDataType in interface Vendor

Overrides:

getDataType in class SQL92

Parameters:

jdbcType - A java.sql.Types constant

name - The type name, as reported by java.sql metadata methods, normalized to uppercase

size - Character size of the type, or 0 if not applicable

Returns:

A compatible D2RQ DataType instance, or null if the vendor code is broken

booleanExpressionToSimpleExpression

public Expression booleanExpressionToSimpleExpression(Expression expression)

Expressions can not return true or false in Microsoft SQL Server. (No boolean type) But, the entire expression can be moved inside a CASE WHEN statement to return an int for the boolean result.

Specified by:

booleanExpressionToSimpleExpression in interface Vendor

Overrides:

booleanExpressionToSimpleExpression in class SQL92

Parameters:

expression - A boolean expression

Returns:

A simple expression returning an equivalent value, e.g., INT 0 and 1

isIgnoredTable

public boolean isIgnoredTable(String schema,
                     String table)

Description copied from interface: Vendor

TODO Use the Filter interface for this

Specified by:

isIgnoredTable in interface Vendor

Overrides:

isIgnoredTable in class SQL92

Parameters:

schema - A schema name, or null for the connection's default schema

table - A table name

Returns:

true if this is a system table that doesn't contain user/application data