Using &NDB Verbs › Work with NDBs › Retrieve Records from an NDB › Retrieve Records Sequentially by Key Field

Retrieve Records Sequentially by Key Field

When you want to retrieve records by any key sequence, the following technique can be used:

&NDBSEQ dbname DEFINE SEQ=seqname FIELD=keyfieldname +
FROM=fromvalue TO=tovalue
&NDBGET loop as coded in previous example..... 

This use of &NDBSEQ and &NDBGET allows sequential retrieval by any key field, and, for non-unique key fields, records with the same key field value are returned in RID sequence within the value.

The FROM and TO operands on &NDBSEQ are optional. If omitted, the lowest (FROM) or highest (TO) key values are used. For non-unique key fields, VALUE=value can be coded to indicate the from and to values are the same. This is useful when you want to read all records with the same non-unique value. For character and HEX fields, GENERIC=value can be coded to indicate the range is to cover all records with that generic key value.