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 Syntax    db.query    db.reader    db.field

Related Concepts    Using the OMDB library

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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