modify: syntax and options

Terms in italic typeface are option strings you supply. When your option string contains a space or a tab character, you must enclose it in single quotes.

modify ' modify_spec1 ;modify_spec2 ; ...  modify_specn ;'

where each modify_spec specifies a conversion you want to perform. Performing conversions describes the conversions that the modify operator can perform.

• Enclose the list of modifications in single quotation marks.
• Separate the modifications with a semi-colon.
• If modify_spec takes more than one argument, separate the arguments with a comma and terminate the argument list with a semi-colon, as in the following example:

  
  modify 'keep field1,field2, ... fieldn;'
  

Multi-byte Unicode character data is supported for fieldnames in the modify specifications below.

The modify_spec can be one of the following:

• DROP
• KEEP
• replacement_spec
• NOWARN

To drop a field:

DROP fieldname [, fieldname ...]

To keep a field:

KEEP fieldname [, fieldname ...]

To change the name or data type of a field, or both, specify a replacement-spec, which takes the form:

new-fieldname [:new-type] = [explicit-conversion-spec] 
   old-fieldname

Replace the old field name with the new one. The default type of the new field is the same as that if the old field unless it is specified by the output type of the conversion-spec if provided. Multiple new fields can be instantiated based on the same old field.

When there is an attempt to put a null in a field that has not been defined as nullable, InfoSphere® DataStage® issues an error message and terminates the job. However, a warning is issued at step-check time. To disable the warning, specify the NOWARNF option.