Require SQL Where Clause
========================

`safeupdate` is a simple extension to PostgreSQL that raises an error if
`UPDATE` and `DELETE` are executed without specifying conditions.  This
extension was initially designed to protect data from accidental obliteration of
data that is writable by [PostgREST].

Installation
------------

Build from source using

    gmake
    gmake install

Or from [PGXN]

    pgxn install safeupate

Activate per-session by running

    load 'safeupdate';

Make this mandatory for all databases and connections by adding the following to
`postgresql.conf`:

    :::ini
    shared_preload_libraries=safeupdate

Examples
--------

Try to update records without `WHERE` clause

    :::sql
    UPDATE FROM rack SET fan_speed=70;
    -- ERROR:  UPDATE requires a WHERE clause

Select results from a CTE that attempts to modify data:

    :::sql
    WITH updates AS (
      UPDATE rack SET fan_speed=70
      RETURNING *
    )
    SELECT * FROM updates;
    -- ERROR:  UPDATE requires a WHERE clause

Set a column value for a range of records

    :::sql
    UPDATE rack SET fan_speed=90 WHERE fan_speed=70;

Set a column value for all the records in a table

    :::sql
    UPDATE rack SET fan_speed=90 WHERE 1=1;

Options
-------

Once loaded this extension can be administratively disabled per sesison by
setting

    :::sql
    SET safeupdate.enabled=0;

or per database using

    :::sql
    ALTER DATABASE mydb SET safeupdate.enabled=off;

News
----

A release history as well as features in the upcoming release are covered in the
[NEWS] file.

License
-------

Source is under and ISC-style license. See the [LICENSE] file for more detailed
information on the license used for compatibility libraries.

[NEWS]: http://www.bitbucket.org/eradman/pg-safeupdate/src/default/NEWS
[LICENSE]: http://www.bitbucket.org/eradman/pg-safeupdate/src/default/LICENSE
[PostgREST]: http://postgrest.com
[PGXN]: http://pgxn.org