Reading database records using a keyed sequence access path

 

These read operations can be used with a keyed sequence access path to get database records. When a keyed sequence access path is used, a read operation cannot position to the storage occupied by a deleted record.

The system performs the read operations based on the statements that you specify using your high-level language. Your high-level language might not allow all of the following operations. See your high-level language topic collection to determine which operations are allowed by the language.

• Reading next operation
  This operation gets the next record on the keyed sequence access path.

• Reading previous operation
  This operation gets the previous record on the keyed sequence access path.

• Reading first operation
  This operation gets the first record on the keyed sequence access path.

• Reading last operation
  This operation gets the last record on the keyed sequence access path.

• Reading same operation
  This operation gets the record that is identified by the current file position. The position in the file is not changed.

• Reading by key operation
  This operation gets the record identified by the key value.

• Reading by relative record number operation
  For a keyed sequence access path, the relative record number can be used. This is the relative record number in the arrival sequence, even though the member opened has a keyed sequence access path.

• Reading when logical file shares an access path with more keys operation
  When the First-In First-Out (FIFO), Last-In First-Out (LIFO), or First-Changed First-Out (FCFO) keyword is not specified in the data description specifications (DDS) for a logical file, the logical file can implicitly share an access path that has more keys than the logical file being created.

 

Parent topic:

Reading database records