mirror of
https://github.com/pgadmin-org/pgadmin4.git
synced 2024-11-21 16:27:39 -06:00
66 lines
2.4 KiB
ReStructuredText
66 lines
2.4 KiB
ReStructuredText
.. _check_dialog:
|
|
|
|
*********************
|
|
`Check Dialog`:index:
|
|
*********************
|
|
|
|
Use the *Check* dialog to define or modify a check constraint. A check
|
|
constraint specifies an expression that produces a Boolean result that new or
|
|
updated rows must satisfy for an insert or update operation to succeed.
|
|
|
|
The *Check* dialog organizes the development of a check constraint through the
|
|
*General* and *Definition* tabs. The *SQL* tab displays the SQL code generated
|
|
by dialog selections.
|
|
|
|
.. image:: images/check_general.png
|
|
:alt: Check dialog general tab
|
|
:align: center
|
|
|
|
Use the fields in the *General* tab to identify the check constraint:
|
|
|
|
* Use the *Name* field to provide a descriptive name for the check constraint
|
|
that will be displayed in the *pgAdmin* tree control. With PostgreSQL 9.5
|
|
forward, when a table has multiple check constraints, they will be tested for
|
|
each row in alphabetical order by name and after NOT NULL constraints.
|
|
* Store notes about the check constraint in the *Comment* field.
|
|
|
|
Click the *Definition* tab to continue.
|
|
|
|
.. image:: images/check_definition.png
|
|
:alt: Check dialog definition tab
|
|
:align: center
|
|
|
|
Use the fields in the *Definition* tab to define the check constraint:
|
|
|
|
* Provide the expression that a row must satisfy in the *Check* field.
|
|
* Move the *No Inherit?* switch to the *Yes* position to specify that this
|
|
constraint is not automatically inherited by a table's children. The default
|
|
is *No*, meaning that the constraint will be inherited by any children.
|
|
* Move the *Don't validate?* switch to the *No* position to skip validation of
|
|
existing data; the constraint may not hold for all rows in the table. The
|
|
default is *Yes*.
|
|
|
|
Click the *SQL* tab to continue.
|
|
|
|
Your entries in the *Check* dialog generate a SQL command (see an example
|
|
below). Use the *SQL* tab for review; revisit or switch tabs to make any changes
|
|
to the SQL command.
|
|
|
|
**Example**
|
|
|
|
The following is an example of the sql command generated by user selections in
|
|
the *Check* dialog:
|
|
|
|
.. image:: images/check_sql.png
|
|
:alt: Check dialog sql tab
|
|
:align: center
|
|
|
|
The example shown demonstrates creating a check constraint named *jobhist_date_chk*
|
|
on the *startdate* column of the *jobhist* table.
|
|
|
|
|
|
* Click the *Info* button (i) to access online help.
|
|
* Click the *Save* button to save work.
|
|
* Click the *Close* button to exit without saving work.
|
|
* Click the *Reset* button to restore configuration parameters.
|