The *DBCOLUMN command checks whether a column exists in a sheet. The form of the *DBCOLUMN command is:

[*DBCOLUMN hascolumnindex = fileindex;sheetname;columnname]

Where the index name fileindex was used in the *DBOPEN command. The file must be open when *DBCOLUMN is used.

The sheetname is the name of the sheet in the Excel file or table in the Access file..

The index name hascolumnindex is set to 1 if the column exists in the named worksheet. It is set to zero if the column is not found.

It is more efficient to use *DBCOLUMN before *DBLOOP rather than inside a loop between *DBLOOP and *DBEND.

Any number of *DBCOLUMN commands can be used on an open file.

Examples of *DBCOLUMN commands:

[*dbopen dfNameFile=Names.xls]

[*dbcolumn HasAddress=dfNameFile;Names;Address]

[*dbcolumn HasPostcode=dfNameFile;Names;Postcode]

[*set HasEither=HasAddress+HasPostcode]

[*dbloop dlList=dfNameFile;Names]

[*skip 99 on HasEither.gt.0]

[dlList.Name] has no address nor postcode


[*dbend dlList]

[*dbclose dfNameFile]