org.teiid.translator.jdbc
Class LocateFunctionModifier

java.lang.Object
  org.teiid.translator.jdbc.FunctionModifier
      org.teiid.translator.jdbc.AliasModifier
          org.teiid.translator.jdbc.LocateFunctionModifier

Direct Known Subclasses:

LocateFunctionModifier

public class LocateFunctionModifier
extends AliasModifier

A modifier class that can be used to translate the scalar function locate(search_string, source_string) and locate(search_string, source_string, start_index) to a function or expression that can be used at the data source.

If the default implementation is used, a function name of LOCATE will be used for the function name.

If the default implementation is used, the expression will not be modified if:

locate(search_string, source_string) is used

locate(search_string, source_string, start_index) is used and start_index is a literal integer greater then 0

the default function parameter order is used or unspecified

If the default implementation is used, the expression will be modified if:

locate(search_string, source_string, start_index) is used and start_index is a literal integer less then 1

locate(search_string, source_string, start_index) is used and start_index is not a literal integer

the function parameter order is something other than the default

If the default implementation is used and the expression is modified, it is modified to ensure that any literal integer value less than 1 is made equal to 1 and any non literal value is wrapped by a searched case expression to ensure that a value of less then 1 will be equal to 1 and the parameter order matches that of what the data source expects.

For example:

locate('a', 'abcdef') --> LOCATE('a', 'abcdef')

locate('a', 'abcdef', 2) --> LOCATE('a', 'abcdef', 2)

locate('a', 'abcdef', 0) --> LOCATE('a', 'abcdef', 1)

locate('a', 'abcdef', intCol) --> LOCATE('a', 'abcdef', CASE WHEN intCol < 1 THEN 1 ELSE intCol END)

Since:

6.2

Field Summary

static java.lang.String

LOCATE

Fields inherited from class org.teiid.translator.jdbc.AliasModifier

alias

Fields inherited from class org.teiid.translator.jdbc.FunctionModifier

BIGDECIMAL, BIGINTEGER, BLOB, BOOLEAN, BYTE, CHAR, CLOB, DATE, DOUBLE, FLOAT, INTEGER, LONG, OBJECT, SHORT, STRING, TIME, TIMESTAMP, XML

Constructor Summary

LocateFunctionModifier(LanguageFactory langFactory)
Translates the scalar function LOCATE() to a source specific scalar function or expression.

LocateFunctionModifier(LanguageFactory langFactory, java.lang.String functionName, boolean sourceStringFirst)
Translates the scalar function LOCATE() to a source specific scalar function or expression.

Method Summary

protected LanguageFactory	getLanguageFactory() Get the instance of LanguageFactory set during construction.
void	modify(Function function) Returns a version of function suitable for executing at the data source.

Methods inherited from class org.teiid.translator.jdbc.AliasModifier

translate

Methods inherited from class org.teiid.translator.jdbc.FunctionModifier

getCode

Methods inherited from class java.lang.Object

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

Field Detail

LOCATE

public static java.lang.String LOCATE

Constructor Detail

LocateFunctionModifier

public LocateFunctionModifier(LanguageFactory langFactory)

Translates the scalar function LOCATE() to a source specific scalar function or expression.

Parameters:

langFactory - the language factory associated with translation

LocateFunctionModifier

public LocateFunctionModifier(LanguageFactory langFactory,
                              java.lang.String functionName,
                              boolean sourceStringFirst)

Translates the scalar function LOCATE() to a source specific scalar function or expression.

Parameters:

langFactory - the language factory associated with translation

functionName - the function name or alias to be used instead of LOCATE

sourceStringFirst -

Method Detail

modify

public void modify(Function function)

Returns a version of function suitable for executing at the data source.

For example:

locate('a', 'abcdefg') ---> LOCATE('a', 'abcdefg')
locate('a', 'abcdefg', 1) ---> LOCATE('a', 'abcdefg', 1)
locate('a', 'abcdefg', 1) ---> INSTR('abcdefg', 'a', 1)
locate('a', 'abcdefg', -5) ---> INSTR('abcdefg', 'a', 1)
locate('a', 'abcdefg', 1) ---> FINDSTR('a', 'abcdefg', 1)
locate('a', 'abcdefg', myCol) ---> LOCATE('a', 'abcdefg', CASE WHEN myCol < 1 THEN 1 ELSE myCol END)

Overrides:

modify in class AliasModifier

Parameters:

function - the LOCATE function that may need to be modified

getLanguageFactory

protected LanguageFactory getLanguageFactory()

Get the instance of LanguageFactory set during construction.

Returns:

the ILanguageFactory instance