Override functionality allows to change column value and attributes in the child tables extended from the base table. For example, a column override changes the default value of the Impact field from Low in the Task table to Medium in the Incident table.
Role required: admin.
How to define a column override
- Navigate to System Definition → Column Overrides.
- Click New and fill in the fields.
- Click Save or Save and Exit to apply changes.
Column Override form fields
| Field | Mandatory | Description |
|---|---|---|
| Base Table | Y | In this dictionary field, you can select the uppermost (in terms of inheritance) table containing the field to override. |
| Table | Y | In this dictionary field, you can select the child table that will be affected by overriding. |
| Column | Y | In this dictionary field, you can select a column to be overridden. |
| Display by Ref Override | N | Select this checkbox if you need to override the Display by Ref setting which is responsible for what column will be displayed instead of reference IDs. |
Default Value Override | N | Select this checkbox to display the Default Value field, which overrides the default value for the field on the extended table. After selecting this checkbox, the Default Value field appears. Enter the default value that will override the original one. |
| Reference Qualifier Override | N | Select the checkbox to display the Reference Qualifiers fieldset, which overrides the reference qualifier for the field on the extended table.
|
| Mandatory Override | N | Select the checkbox to display the Mandatory field, which overrides whether the field on the extended table must contain a value to save a record. |
| Read Only Override | N | Select this checkbox to display the Read Only field, which overrides whether a user can change the field value on the extended table. |
| Dependent on Column ID Override | N | Select this checkbox to display the Dependent on Column field, which overrides the field on which the current field depends. |
Override example
As an example, you may need to override some column where the base table and the child table are the same. This can help as a workaround in case if you need to change some protected column options before they are changed correctly.
When doing this, please keep in mind that inaccurate changes may harm your system, so recheck twice, and verify on some testing instance firstly if possible.
To perform such override, please fill in the fields as described below when filling in the column overriding form:
- Base Table - select a base table.
- Table - select the same table.
- Column - select a column you need to override.
- Specify an attribute you are going to override. These column attributes can be overridden:
- Mandatory
- Read Only
- Display by Ref
- Reference Qualifier
- Dependent on Column
- Default Value
- Specify new attribute value.
- Click Save or Save and Exit to apply changes.
To be more specific, have a look on the screenshot below. It shows the Mandatory attribute overriding of the IT Service column related to the Agreement table.
Defining an override for choice fields
When creating a choice-like field (for example, Choice), it is recommended to set text values in the Value field to increase code readability. For example, it can be Incoming, or Active, or Failed values.
Regarding task states, it makes sense to make values numerical; this can help with selection construction (see the code sample below).
task.addQuery('state', '>', '2'); // all states after In Progress
