displayColumn attribute

Defines which column is used as an identifier for the user.

Content Type

unsignedInt

Parent

ArrayOptions

Remarks

This column has to be of type “String”. It can be updated, and normally contains a readable key which identifies the row for the user.

Note

For performance reasons, using either the "naming" option or the NamingFormat tag is favored over using the displayColumn attribute for new protocols.

Caution

Depending on how the display key is defined, there is an important difference in the way trend data is stored in the trend data database table. If the displayColumn attribute is used, the display key is used in the trend data table. In case either the Naming option or NamingFormat is used, the primary key is used in the trend data table.

You should therefore never change existing protocols to start using naming instead of the displayColumn attribute, as this would result in the trend history becoming unavailable (even though it would still be present in the database).

See also

• Display keys
• Protocol.Params.Param.ArrayOptions.NamingFormat
• naming