37.22 GET_ORDERBY_NULLS_SUPPORT Function
This function checks whether the current data source is enabled to specify a NULLS
clause for sorting. While this is always true for local and REST-enabled SQL, some REST APIs may not support it.
Plug-in developers can use this function to determine whether a NULLS
clause is possible for this data source and show or hide these options in their UI.
You can specify a NULLS FIRST
or NULLS LAST
clause if one of the following conditions is true:
- You are working against the local database or a REST-enabled SQL Service.
- The REST API disables pagination. You always fetch all rows and sort locally.
- The REST API disables server-side ordering. You must fetch all rows and sort locally.
- The REST API enables pagination, supports server-side ordering, and includes an
ORDER BY NULLS
clause.
Syntax
APEX_PLUGIN_UTIL.GET_ORDERBY_NULLS_SUPPORT (
parameter_1 IN NUMBER,
parameter_2 IN VARCHAR2,
parameter_3 IN NUMBER )
Returns
This function returns an instance of APEX_EXEC.T_SUPPORTS_ORDERBY_NULLS_AS
which indicates whether ORDER BY NULLS
clauses are supported or how the REST API treats NULLS
when ordering.
Table 37-29 GET_ORDERBY_NULLS_SUPPORT Returns
Return | Description |
---|---|
wwv_flow_exec_api.c_orderby_nulls_flexible |
The data source supports ORDER BY NULLs clauses. |
wwv_flow_exec_api.c_orderby_nulls_are_lowest |
The data source treats NULLs as the lowest values when sorting. |
wwv_flow_exec_api.c_orderby_nulls_are_highest |
The data source treats NULLs as the highest values when sorting. |
wwv_flow_exec_api.c_orderby_nulls_always_last |
The data source always orders NULLs last. |
wwv_flow_exec_api.c_orderby_nulls_always_first |
The data source always orders NULLs first. |
Example
DECLARE
l_supports_orderby_nulls apex_exec.t_supports_orderby_nulls_as;
BEGIN
l_supports_orderby_nulls := apex_plugin_util.get_orderby_nulls_support;
IF l_supports_orderby_nulls = wwv_flow_exec_api.c_orderby_nulls_flexible THEN
...
END IF;
END;
Parent topic: APEX_PLUGIN_UTIL