From f8e5787ac0988bdd32cf8d8560c57b07e8cd1bc9 Mon Sep 17 00:00:00 2001 From: Christophe Eymard Date: Thu, 28 Nov 2024 19:58:15 +0100 Subject: [PATCH] docs: added nullif use in current_setting default value use case --- docs/references/configuration.rst | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/docs/references/configuration.rst b/docs/references/configuration.rst index 9f5d3f16a3..6a89a02925 100644 --- a/docs/references/configuration.rst +++ b/docs/references/configuration.rst @@ -193,7 +193,7 @@ app.settings.* When using the environment variable `PGRST_APP_SETTINGS_*` form, the remainder of the variable is used as the new name. Case is not important : :code:`PGRST_APP_SETTINGS_MY_ENV_VARIABLE=some_value` can be accessed in postgres as :code:`current_setting('app.settings.my_env_variable')`. - The :code:`current_setting` function has `an optional boolean second `_ argument to avoid it from raising an error if the value was not defined. Default values to :code:`app.settings` can then easily be given by combining this argument with :code:`coalesce` : :code:`coalesce(current_setting('app.settings.my_custom_variable', true), 'default value')` + The :code:`current_setting` function has `an optional boolean second `_ argument to avoid it from raising an error if the value was not defined. Default values to :code:`app.settings` can then easily be given by combining this argument with :code:`coalesce` and :code:`nullif` : :code:`coalesce(nullif(current_setting('app.settings.my_custom_variable', true), ''), 'default value')`. The use of :code:`nullif` is necessary because if set in a transaction, the setting is sometimes not "rolled back" to :code:`null`. See also :ref:`this section ` for more information on this behaviour. .. _db-aggregates-enabled: