Library: Database access (OMDB) Import: omdb.xmd

Return type: Switch Returns: TRUE if the field value is SQL NULL, or FALSE otherwise.

Declaration

define external switch function db.is-null value db.field field

      

Argument definitions

field

is a db.field object associated with a field in the current record in an active SQL query record set.

Use db.is-null to check whether or not a field in a database record contains a NULL value.

Requirements

The database connection represented by db.database must be:

• open (else external exception OMDB209)
• in scope (else external exception OMDB103)

The db.field object field must be associated with a query (else external exception OMDB302).

The data cursor must be positioned on an existing row (else external exception OMDB205).

Usage Notes

The data cursor points to the record set's currently active row.

The function uses a db.field shelf variable containing a record set created by db.query, db.execute, or db.streaming-execute.

Function db.reader with the optional argument null provides another way of handling NULL field values in the record set.

Example

         repeat
           exit unless db.record-exists my-record
  
           output '<record%n'
           repeat over my-record as my-field
              output '%_%_' || key of my-field || '="' || db.reader of my-field || '"%n'
                 unless db.is-null my-field
           again
           output '/>%n'
  
           db.move-record my-record
         again

Related Topics Using the OMDB library db.query db.reader db.field

Other Library Functions db.advance-recordset db.close db.commit db.compile-statement db.database db.delete db.discard db.document-writer-sedna db.execute db.execute-in db.field db.insert db.is-null db.move-dynamic-record db.move-record db.omdb-version db.omdb-version-oci10g db.omdb-version-oci11g db.omdb-version-oci8i db.omdb-version-oci9i db.omdb-version-odbc db.omdb-version-sedna db.open-oci10g db.open-oci11g db.open-oci8i db.open-oci9i db.open-odbc db.open-procedure db.open-sedna db.open-table db.prepare db.procedure db.query db.reader db.record-exists db.rollback db.set-transaction-type db.statement db.streaming-execute db.table db.update db.writer

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