Field mapping functionality gives you an option to compare table images that would be not comparable using the standard function. When table images are compared following restrictions apply:

• Key fields
  • Order in before and after image must be the same
  • Underlying data element must be the same
• Value fields
  • Name must be the same while the position isn't important

A comparison of two different tables is often not possible due to these restrictions. Correctly defined field mapping gives you better flexibility for comparing different tables.

Field mapping definition

A new field mapping can be defined in two ways:

1. The first option is in the table variant definition screen. For more information about the variant, definition see the chapter Table Definition.
   1. Fill Field Mapping ID into the corresponding screen field.
      
   2. Double click on the specified name to create new field mapping. Screen for Field Mapping Definition is displayed. 
      1. If a field mapping with the same name already exists, you are redirected to the screen for Field Mapping Definition of an existing mapping. 
2. The second option is to execute the program /DVD/EQS_TABE_FLDMAP
   1. List of available field mappings is displayed
      
   2. To add a new mapping, add a row to the list and provide a technical Field Mapping ID.
   3. To delete an existing mapping, remove rows from the list.
   4. To edit an existing mapping, double click on the particular row.

Field Mapping Definition screen

In Field Mapping Definition you define:

Name mapping

• This mapping renames the output column of a table variant from value A to value B. Use this mapping to match value fields with a different name so they may be compared.
• To define the name mapping enter a column name of the original table in Old Field Name and the new column name in the New Field Name.

Data element mapping

• This mapping converts values of column A from an old data element to a new data element. Use this mapping to compare key fields with different data elements. 
• To define the data element mapping you may either fill the original Old Data element or the original Old Field Name and the New Data element.
• The restriction of the same order of keys still applies for key fields.

Data type mapping

• This mapping converts values of column A from an old data type to a new data type. Use this mapping to compare key fields with different data types in the case data elements are not defined.
• To define the data type mapping click Show Advanced Mapping to display columns for the New Data type, New length and New Decimals. You may enter either the original Old Data element or original Old Field Name and the New Data type. 
  Enter also New length and New decimal places if it is necessary.
• The restriction on the order of keys also applies.

• Use standard functions to add or remove new mappings. 
• Change values in the particular table columns to edit existing mappings.
• You can specify the renaming and conversion of table columns at once by defining values in all four fields.