named: [data base=``database'' field=``field'' key=``key'' value=``value'' op=``increment] )
positional: [data area field key ``value''* increment*]
HTML example: <PARAM MV=data MV.TABLE=database MV.COL=field MV.ROW=key>
Returns the value of the field in any of the arbitrary databases, or from the variable namespaces. If the optional value is supplied, the database value will be changed to it -- no ] characters may be present in the value unless using the new tag style. If the option increment* is present, the field will be atomically incremented with the value in value.
If a DBM-based database is to be modified, it must be flagged writable on
the page calling the write tag. Use [tag flag write]products[/tag] to mark
the products
database writable, for example.
In addition, the [data ...] tag can access a number of elements in the MiniVend session database:
accesses Accesses within the last 30 seconds arg The argument passed in a [page ...] or [area ...] tag browser The user browser string host MiniVend's idea of the host (modified by DomainTail) last_error The last error from the error logging last_url The current MiniVend path_info logged_in Whether the user is logged in (add-on UserDB feature) pageCount Number of unique URLs generated prev_url The previous path_info referer HTTP_REFERER string ship_message The last error messages from shipping source Source of original entry to MiniVend time Time (seconds since Jan 1, 1970) of last access user The REMOTE_USER string username User name logged in as (add-on UserDB feature)
Databases will hide variables, so don't name a database ``session'', ``scratch'', or any of the other reserved names or you won't be able to use the [data ...] tag to read them. Case is sensitive, so in a pinch you could call the database ``Session'', but it would be better not to.