PostgreSQL 11 Administration Cookbook

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Conditional statements are usually part of flow-control statements, which also include iterations.

While iterating is not directly supported by psql, a similar effect can be achieved in other ways, for instance:

• A script called file.sql (for instance) can be iterated by adding some lines at the end, as in the following fragment:

SELECT /* add a termination condition as appropriate */ AS do_loop\gset\if do_loop\ir file.sql\endif

• Instead of iterating, you can follow the approach described later in this chapter in the Performing actions on many tables recipe.