WRITE statements in Extract-Phase Column Logic

TABLE OF CONTENTS

1. How do I use WRITE Statements in ECL?
2. Syntax
3. Rules for the syntax
4. Examples: IF with WRITE in Extract Column Logic

How do I use WRITE Statements in ECL?

WRITE statements are optional in your Extract-Phase Column Logic text. If there are no WRITE statements in ECL, then there must be a WRITE statement either from the default Extract-Phase Record Logic, or provided in the overriding Extract-Phase Record Logic.

A default WRITE (in Extract-Phase Record Logic) still occurs if you provide WRITE statements in your Extract-Phase Column Logic text.

A WRITE statement in your Extract-Phase Column Logic text allows the following:

• Writing records to logical files of your choice.
• Performing a procedure or user-exit routine on input records.
• Writing only some of the columns.
• Writing multiple output records for each record read.
• A combination of the above.

Here are some example cases of a WRITE in Extract-Phase Column Logic:

• Write a full copy of the selected input record to a view output file
  (SOURCE=INPUT, DEST=FILE=LogicalFile).
• Write all columns up to that point to a named logical file. The file must be a view output file
  (SOURCE=DATA, DEST=FILE=LogicalFile)
• Write all columns up to that point to an extract work file that can be processed in the format phase
  (SOURCE=VIEW, DEST=EXTRACT=number).
  The default extract work file number is defined on the Extract Phase tab of the view. The ddname of the extract file is of the form EXTRnnn where nnn is the work file number.
• Pass output records to a procedure or user-exit routine
  (USEREXIT=User_Exit_name or PROCEDURE=Executable_name).

Only the EXTRACT work files are processed in the format phase. All other records written in the above choices are written to view output files and not processed any further after the extract phase.

These WRITE options provide great flexibility in view processing.

The syntax details of a WRITE statement in Extract-Phase Column Logic are shown below.

Syntax

Rules for the syntax

You can use a WRITE statements in Extract Column Logic and Extract Record Logic

You can have as many WRITE statements as required in your logic text.

See also topic: Rules for all Logic Text

Examples: IF with WRITE in Extract Column Logic

Example logic text	Meaning
IF (ISNUMERIC({field4}) AND      ({field5} > {field6} * 10) AND      ISNOTSPACES({field7})) THEN     WRITE (SOURCE=DATA,     USEREXIT={DB2_Update}) ENDIF	If field4 is numeric and field5 is greater than field6 times 10 and field7 is not spaces, then call the user-exit routine DB2_Update for the columns up to the current point. This effectively does a writes to a DB2 table the columns in that record up to the current point.
IF (ISNOTNULL({field3}) AND      ({field2} = {field1} + {field5}) THEN     WRITE SOURCE=INPUT,  DEST=FILE= {LogicalFile3}) ENDIF	If field3 is not nulls and field2 equals field1 plus field 5 then write the entire input record to LogicalFile3. All columns in the input record are included, no matter what column contains this logic text.
IF (DAYSBETWEEN({field12},{field15}) > 10) AND     (ISFOUND({Lookup3;$SYM=”A”})) THEN      WRITE (SOURCE=VIEW, DEST=EXTRACT) ENDIF	If field12 and field15 are more than 10 days apart, and a record is found for the lookup path Lookup3 with symbol SYM set to “A”, then write the columns up to the current point to the extract work file. The extract work file number is defined on the Extract Phase tab of the view.