Any changes to the data made by users of the application are recorded in history of changes. The administrator of the application through the "History" functionality of “Diaries” submenu in the "Administration" menu has access to the register of these changes with the possibility of filtering and browsing. It is possible to filter by any combination of the following criteria:

• date of change – period in which the change was made (from ... to ...)
• changer login – name of user, who made a change
• table name – the name of the database table in which the change was made; when you enter a name of table, hints are displayed
• name of table field (column) – name of the column (field), which value has been changed; when you enter a name of field, hints are displayed
• table record id – row’s (record’s) identifier that has been modified

After the entering restrictions in the filter and pressing the button, there is displayed a paged table of registered changes that meet the filter’s criteria. By default, changes are displayed in order from most recent to the oldest, but the display order can be changed by clicking on the corresponding column of the header of the table with the list of changes. In the list of changes are presented the following information: the date of change, the login of changer, the name of table, the name of fields (columns) in the table, the ID of record in the table, the value before the change, the value after the change. If the field on which the change was made is the "id" filed and the value before the change is blank and the value after the change is the same as the record identifier, it means making a new record in the table. If the field on which the change was made is the "status" field and the value before the change is "N" and the value after the change is "D" then it means the removal (logical) of the record from the table.