org.eigenbase.sql.type
Class SqlTypeTransforms

java.lang.Object
  org.eigenbase.sql.type.SqlTypeTransforms

public abstract class SqlTypeTransforms
extends Object

SqlTypeTransforms defines a number of reusable instances of SqlTypeTransform.

NOTE: avoid anonymous inner classes here except for unique, non-generalizable strategies; anything else belongs in a reusable top-level class. If you find yourself copying and pasting an existing strategy's anonymous inner class, you're making a mistake.

Version:

$Id: //open/dev/farrago/src/org/eigenbase/sql/type/SqlTypeTransforms.java#9 $

Author:

Wael Chatila

Field Summary

static SqlTypeTransform	forceNullable Parameter type-inference transform strategy where a derived type is transformed into the same type with nulls allowed.
static SqlTypeTransform	onlyColumn Parameter type-inference transform strategy where a derived type must be a struct type with precisely one field and the returned type is the type of that field.
static SqlTypeTransform	toMultisetElementType Parameter type-inference transform strategy where a derived type must be a multiset type and the returned type is the multiset's element type.
static SqlTypeTransform	toNullable Parameter type-inference transform strategy where a derived type is transformed into the same type but nullable if any of a calls operands is nullable
static SqlTypeTransform	toVarying Type-inference strategy whereby the result type of a call is VARYING the type given.

Constructor Summary

SqlTypeTransforms()

Method Summary

Methods inherited from class java.lang.Object

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

Field Detail

toNullable

public static final SqlTypeTransform toNullable

Parameter type-inference transform strategy where a derived type is transformed into the same type but nullable if any of a calls operands is nullable

forceNullable

public static final SqlTypeTransform forceNullable

Parameter type-inference transform strategy where a derived type is transformed into the same type with nulls allowed.

toVarying

public static final SqlTypeTransform toVarying

Type-inference strategy whereby the result type of a call is VARYING the type given. The length returned is the same as length of the first argument. Return type will have same nullablilty as input type nullablility. First Arg must be of string type.

toMultisetElementType

public static final SqlTypeTransform toMultisetElementType

Parameter type-inference transform strategy where a derived type must be a multiset type and the returned type is the multiset's element type.

See Also:

MultisetSqlType.getComponentType()

onlyColumn

public static final SqlTypeTransform onlyColumn

Parameter type-inference transform strategy where a derived type must be a struct type with precisely one field and the returned type is the type of that field.

Constructor Detail

SqlTypeTransforms

public SqlTypeTransforms()