revDatabaseColumnNumbered

Typefunction
DictionaryLCS
LibraryLiveCode Script
Syntax
revDatabaseColumnNumbered(<recordSetID>, <columnNumber> [, <holderVariable>])
Synonymsrevdb_columnbynumber
Associationsdatabase library
Summary

Returns data from a specified database field.

Introduced1.1
Changes

The ability to specify an array element as a holder variable was added in version 2.9.

OSmac, windows, linux, ios, android
Platformsdesktop, server, mobile
Parameters
NameTypeDescription
recordSetID

The number returned by the revQueryDatabase when the record set was created.

columnNumber

The number of a database field.

holderVariable

Any valid variable name or the name of an array element.

Example
revDatabaseColumnNumbered(customerServiceDB, 3)
revDatabaseColumnNumbered(7, 3, "tNewColumn") -- puts column 3 into tNewColumn
revDatabaseColumnNumbered(USCustomers, x, "tFoundZipCodes")
revDatabaseColumnNumbered(tCursor, 1, "tRetrievedDataArray[id]")
Values
NameTypeDescription
return

If no holderVariable is specified, the revDatabaseColumnNumbered function returns text data from the specified field of the current record. If a holderVariable is specified, then the function returns empty and the text data from the specified field of the current record is placed in that variable.

RelatedControl Structure: function
Library: Database library
Keyword: string
Constant: empty
Function: revDatabaseColumnCount, revCurrentRecord, revDatabaseColumnNamed, revDatabaseColumnLengths, revDatabaseColumnIsNull
Command: revMoveToLastRecord, revMoveToFirstRecord, revMoveToNextRecord
Glossary: LiveCode custom library, return, variable, record set, record, Standalone Application Settings, standalone application, database field
Securitydisk, network
Description

Use the revDatabaseColumnNumbered function to obtain the contents of a given database field, in the current record of the specified record set.

If you specify a holderVariable, the data is placed in that variable. Otherwise, the data is returned by the function. In order to retrieve binary data, a holder variable must be specified, otherwise the revDatabaseColumnNumbered function may return truncated data. This is due to limitations in the current architecture.

If the attempt to get the data is not successful, the revDatabaseColumnNumbered function returns an error message that begins with the string "revdberr".

Important: The revDatabaseColumnNumbered function is part of the Database library. To ensure that the function works in a standalone application, you must include this custom library when you create your standalone. In the Inclusions pane of the Standalone Application Settings window, make sure both the "Database" library checkbox and those of the database drivers you are using are checked.

Tagsdatabase