Class FromTypeColumnMappings
The output from a FromTypeColumnMapper<TFrom> row mapper, which maps from the (potentially hierarchical) fields, properties, table columns etc. of a source 'from' .NET CLR type (described by FromRowSchema), to a flat list of user supplied or automatically generated target 'to' columns (described by ToRowSchema).
This class does not include the Row() method,
and should be used when the Row()
method is not supported by the worker in question.
Also see IRowMapperCommand which does include that method.
Also see the Dataflow Column Mapping and Mapping and Copying examples, as well as IRowMapperCommand and IColumnMapperCommand.
Namespace: actionETL
Assembly: actionETL.dll
Syntax
public class FromTypeColumnMappings
Properties
FromMapCounts
Gets an instance that tracks the number of times each 'from' column has been mapped. This is often used to control how a column is copied, e.g. cloning any copies after the first one.
Declaration
public RowSchemaMapCounts FromMapCounts { get; }
Property Value
Type | Description |
---|---|
RowSchemaMapCounts |
FromRowSchema
Gets an instance that describes the 'from' side of the mapping.
Declaration
public TypeRowSchema FromRowSchema { get; }
Property Value
Type | Description |
---|---|
TypeRowSchema |
SchemaMapFromIndexes
Gets the distinct FromIndex 'from' indexes present in SchemaMaps.
Declaration
public IEnumerable<int> SchemaMapFromIndexes { get; }
Property Value
Type | Description |
---|---|
IEnumerable<Int32> |
SchemaMaps
Gets a list of mappings between 'from' columns and 'to' columns in a dataflow row, based on column indexes into the SchemaNodeList list property in FromRowSchema and ToRowSchema.
Declaration
public IReadOnlyList<SchemaMap> SchemaMaps { get; }
Property Value
Type | Description |
---|---|
IReadOnlyList<SchemaMap> |
SchemaMapToIndexes
Gets the distinct ToIndex 'to' indexes present in SchemaMaps.
Declaration
public IEnumerable<int> SchemaMapToIndexes { get; }
Property Value
Type | Description |
---|---|
IEnumerable<Int32> |
ToMapCounts
Gets an instance that tracks the number of times each 'to' column has been mapped. This is often used to guard against multiple mappings to the same column.
Declaration
public RowSchemaMapCounts ToMapCounts { get; }
Property Value
Type | Description |
---|---|
RowSchemaMapCounts |
ToRowSchema
Gets an instance that describes the 'to' side of the mapping.
Declaration
public FlatRowSchema ToRowSchema { get; }
Property Value
Type | Description |
---|---|
FlatRowSchema |
Methods
ToStringMapped()
Return a string that describes how many and which columns have been mapped.
Declaration
public string ToStringMapped()
Returns
Type | Description |
---|---|
String |
ToStringMappedUnmapped()
Return a string that describes how many and which columns have been mapped, as well as which columns are not mapped.
Declaration
public string ToStringMappedUnmapped()
Returns
Type | Description |
---|---|
String |