pgadmin4/docs/en_US/cast_dialog.rst

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.. _cast_dialog:
********************
`Cast Dialog`:index:
********************
Use the *Cast* dialog to define a cast. A cast specifies how to convert a value
from one data type to another.
The *Cast* dialog organizes the development of a cast through the following
dialog tabs: *General* and *Definition*. The *SQL* tab displays the SQL code
generated by dialog selections.
.. image:: images/cast_general.png
:alt: Cast dialog general tab
:align: center
Use the fields in the *General* tab to identify the cast:
* The *Name* field is disabled. The name that will be displayed in the
*pgAdmin* tree control is the *Source* type concatenated with the *Target*
type, and is generated automatically when you make selections on the *Cast*
dialog *Definition* tab.
* Store notes about the cast in the *Comment* field.
Click the *Definition* tab to continue.
.. image:: images/cast_definition.png
:alt: Cast dialog definition tab
:align: center
Use the fields in the *Definition* tab to define parameters:
* Use the drop-down listbox next to *Source type* to select the name of the
source data type of the cast.
* Use the drop-down listbox next to *Target type* to select the name of the
target data type of the cast.
* Use the drop-down listbox next to *Function* to select the function used to
perform the cast. The function's result data type must match the target type
of the cast.
* Select *Context* toggle to *Implicit* if the cast is implicit.
By default, a cast can be invoked only by an explicit cast request. If the
cast is marked *Implicit* then it can be invoked implicitly in any context,
whether by assignment or internally in an expression.
Click the *SQL* tab to continue.
Your entries in the *Cast* 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 *Cast* dialog:
.. image:: images/cast_sql.png
:alt: Cast dialog sql tab
:align: center
* 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.