org.eigenbase.sql2rel
Interface DefaultValueFactory

All Known Implementing Classes:

ReposDefaultValueFactory, SqlToRelConverter.NullDefaultValueFactory

public interface DefaultValueFactory

DefaultValueFactory supplies default values for INSERT, UPDATE, and NEW.

TODO jvs 26-Feb-2005: rename this to InitializerExpressionFactory, since it is in the process of being generalized to handle constructor invocations and eventually generated columns.

Version:

$Id: //open/dev/farrago/src/org/eigenbase/sql2rel/DefaultValueFactory.java#12 $

Author:

John V. Sichi

Method Summary

boolean	isGeneratedAlways(RelOptTable table, int iColumn) Whether a column is always generated.
RexNode	newAttributeInitializer(RelDataType type, SqlFunction constructor, int iAttribute, RexNode[] constructorArgs) Creates an expression which evaluates to the initializer expression for a particular attribute of a structured type.
RexNode	newColumnDefaultValue(RelOptTable table, int iColumn) Creates an expression which evaluates to the default value for a particular column.

Method Detail

isGeneratedAlways

boolean isGeneratedAlways(RelOptTable table,
                          int iColumn)

Whether a column is always generated. If a column is always generated, then non-generated values cannot be inserted into the column.

newColumnDefaultValue

RexNode newColumnDefaultValue(RelOptTable table,
                              int iColumn)

Creates an expression which evaluates to the default value for a particular column.

Parameters:

table - the table containing the column

iColumn - the 0-based offset of the column in the table

Returns:

default value expression

newAttributeInitializer

RexNode newAttributeInitializer(RelDataType type,
                                SqlFunction constructor,
                                int iAttribute,
                                RexNode[] constructorArgs)

Creates an expression which evaluates to the initializer expression for a particular attribute of a structured type.

Parameters:

type - the structured type

constructor - the constructor invoked to initialize the type

iAttribute - the 0-based offset of the attribute in the type

constructorArgs - arguments passed to the constructor invocation

Returns:

default value expression