What does chain do in as400?

CHAIN in rpgle-go4as400.com. The CHAIN command does a SETLL and a READE in order to find a match. CHAIN is best used to locate a unique record (like a customer record) from a full procedural file. In case of CHAIN, the file operation is used to randomly retrieve a record from a file.

What is chain n?

If you are reading from an update disk file, you can specify an N operation extender to indicate that no lock should be placed on the record when it is read (e.g. CHAIN (N)).

How do I read a physical file in Rpgle?

READ opcode in rpgle-go4as400.com. Read operation reads the records of a full procedural file. First of all it reads the record where currently the pointer is and then advances the pointer to the next record. The READ operation applies a record lock to files that are open in update mode.

What is the difference between Reade and chain in as400?

CHAIN is best used to locate a unique record (like a customer record). SETLL with READE is best used when there can be more than one record found. For example, you can find multiple customer orders in your system for one unique customer.

What is Exfmt?

The EXFMT operation is a combination of a WRITE followed by a READ to the same record format. EXFMT is valid only for a WORKSTN file defined as a full procedural combined file that is externally described. The format-name operand must be the name of the record format to be written and then read.

How do you check your Rpgle record lock?

Follow below steps to handle record lock:

  1. Login to Green Screen.
  2. Enter command WRKACTJOB.
  3. Search for the job which is in ‘MSGW’ status.
  4. Take option 7=Display Message.
  5. Note down the file name and library mentioned in the error message.
  6. Press F10=Display messages in job log.

What is data structure in as400?

The ILE RPG compiler allows you to define an area in storage and the layout of the fields, called subfields, within the area. This area in storage is called a data structure. You define a data structure in free form by specifying the DCL-DS operation code followed by the data structure name and keywords.

Which is a collection of related records?

files
Database – is an integrated collection of logically related records or files. A database consolidates records previously stored in separate files into a common pool of data records that provides data for many applications. The data is managed by systems software called database management systems (DBMS).

What is Setll as400?

Ü SETLL (E) (Set Lower Limit) SETLL sets the file pointer at the first occurrence of the record where the key field/RRN value is greater than or equal to the factor-1 search argument value. After positioning the file pointer we can go for any file operation e.g. READ, READP,READPE, READE.

What is the difference between ITER and leave in as400?

The ITER operation takes the control to ENDDO, ENDFOR while LEAVE transfers control to the statement following the ENDDO or ENDFOR operation.