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Model Class

The Model class provides an object that can represent a single row of data from a configured database table. The Service Class works with the Model class when it queries, updates, and deletes records from configured tables.

Event Hooks​

Event hooks are pre-existing methods that are defined on the Model class and are called automatically during the SaveChanges() and DeleteRecord() methods.

These event hooks in the base class are left un-implemented so that they can be overridden in a child class in order to extend functionality.

Below is a list of the event hooks with a short description of when they are invoked and suggestions on how they should be used.

List of Event Hooks​

_DoBeforeSave​

Called before saving any changes (both insert and update).

_DoAfterSave​

Called after any changes have been saved (both insert and update).

_DoBeforeInsert​

Called before inserting a new record.

_DoAfterInsert​

Called after inserting a new record.

_DoBeforeUpdate​

Called before updating an existing record.

_DoAfterUpdate​

Called after updating an existing record.

_DoBeforeDelete​

Called before deleting a record.

_DoAfterDelete​

Called after deleting a record.

Methods​

SaveChanges​

Description​

Saves the data for the model into the database by either inserting a new record or updating an existing record.

Will automatically call relevant Event Hooks.

Syntax​

SaveChanges(txID = None)

  • Parameters
    • string txID - (Optional) The id of a transaction to be used for inserting/updating the database. Defaults to None.

Examples​

tableName = 'myTable'
schema = 'myDB'
service = exchange.pikaview.service_factory.GetModelServiceClass(tableName, schema)
record = service.querySingleById(id = 1)
record.magicnumber = 321
record.SaveChanges()

DeleteRecord​

Description​

Deletes a record from the database.

Will automatically call relevant Event Hooks.

Syntax​

DeleteRecord(txID = None)

  • Parameters
    • string txID - (Optional) The id of a transaction to be used for inserting/updating the database. Defaults to None.

Examples​

tableName = 'myTable'
schema = 'myDB'
service = exchange.pikaview.service_factory.GetModelServiceClass(tableName, schema)
record = service.querySingleById(id = 1)
record.DeleteRecord()