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  • "Null" value supported in key items
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Stored procedures
NullableIndex (Property)
In french: NullIndexé
The NullIableIndex property determines if a key item supports the "Null" value. You can:
  • Determine if a key item supports the "Null" value.
  • Allow or disallow the use of "Null" values in a key item (only when defining the data file programmatically).
Remark: This property is equivalent to the "Allow NULL values in indices (compatible only with version 28 and later)" option in the "Details" tab of the data file description window, in the data model editor.
Caution: Files with the "Allow NULL values in indices" option are only compatible with applications in version 28 or later.
Example
AFile is File Description
AnItem is Item Description
// Describe the "CUSTOMER" data file
AFile.Name = "CUSTOMER"
AFile.Type = hFileNormal
AFile.NullableIndex = True
// Item description
AnItem.Name = "Message"
AnItem.Type = hItemText
AnItem.Size = 40
HDescribeItem(AFile, AnItem)
// Validate the data file description
HDescribeFile(AFile)
Syntax

Determining if a key item supports the "Null" value Hide the details

<Result> = <Data file>.NullableIndex
<Result>: Boolean
  • True if the data file is configured to support "Null" values in a key item,
  • False otherwise.
<Data file>: Character string
Name of the data file used. This name was defined in the data model editor or with the File Description type.

Allowing or disallowing the use of "Null" values in a key item (data file defined programmatically) Hide the details

<Data file>.NullableIndex = <NULL value supported>
<Data file>: Character string
Name of the data file used. This name is defined with the File Description type.
<NULL value supported>: Boolean
  • True if the data file should be configured to support "Null" values in a key item,
  • False otherwise.
Remarks

"Null" value supported in key items

If the keys in the data file support the "Null" value:
  • You can use search functions including the "Null" value.
  • Several keys in the data file can contain the "Null" value.
Minimum version required
  • Version 28
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Last update: 03/06/2024

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