ORM

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'''ORM''' is an '''O'''bject–'''R'''elational database '''M'''apper, being worked on by [DKF].
Currently, it's available in the [http://wiki.tcl.tk/_repo/orm/%|%half-bakery] only. It lacks a number of key features, such as the ability to tell if the database has been changed under its feet.
[chorler] 20230530: link is broken, half-bakery is broken.

It lacks a number of key features, such as the ability to tell if the database has been changed under its feet.

**Documentation**
The object-relational mapper converts a database ''already containing information'' into [oo::class%|%classes] (one per table) and [oo::object%|%objects] (one per row, dynamically loaded). In particular, it introspects the database to discover its primary keys and foreign key relations in order to build the cross-links between table classes. It uses [TDBC] under the hood to actually manage the connections.

***Database Class***
The connection is bound by passing it as the argument when creating the object that represents the overall database:
    :   '''ORM::Database create''' ''dbName tdbcConnection''
''[[TODO: document the operations on dbs and tables]]''
***Row Class***
Each row is represented by an object with one method per column that acts as an accessor for that column:
    :   ''row columnName'' ?''newValue''?
Without the ''newValue'', it returns the current value of the column (which may be the name of an object in another table). With ''newValue'', it updates the column (when setting a column that contains a foreign key, you set in the mapped value and the appropriate key id will be used on the back end).

**Example**
======
package require tdbc::sqlite3
package require ORM

ORM::Database create crm [tdbc::sqlite3::connection new "/path/to/mydatabase.sqlite3"]

crm table order foreach o {
    puts "Order #[$o id]"
    puts "Customer: [[$o customer] firstname] [[$o customer] surname]"
    puts "Address: [[$o dispatch] house] [[$o dispatch] street]"
    puts "Address: [[$o dispatch] city], [[$o dispatch] state]"
    puts "Description:\n\t[$o description]"
}
======

**See also**

https://github.com/rehartmann/toorm%|%toorm%|% - an object relational mapper for Tcl.

<<categories>>Category Database%|%Database | Category Object Orientation%|%OO | Category Package%|%Package