sql - mysql JOIN ON IF()? -

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i trying use sql such this:

select t.*, t2.* templates t left join if(t.t_type = 0,'templates_email', if(t.t_type = 1,'templates_sms','templates_fax')) t2 on t.t_id = t2.t_id;

is possible that?

basically want join on 1 of 3 tables based on value row.

is recommended if possible?

update
so,

basically templates table table contains information every template must have, eg name, id, description

then have templates_x tables these tables contain fields unique each template type.
(there quite few , having single table null fields not applicable not practical).

the tables called templates_x appropriate x stored in templates table int flag.

the join between templates_x tables , templates table through t_id.

so suggest?

is possible that?

no, can't use dynamically assigned tables (join or otherwise) without using dynamic sql syntax (see mysql's preparedstatement syntax).

this non-dynamic re-write of pseudo-query assumes 3 template tables join have same number of columns, , same data types:

select t.*,         te.*   templates t   join templates_email te on te.t_id = t.t_id  t.t_type = 0 union select t.*,         ts.*   templates t   join templates_sms ts on ts.t_id = t.t_id  t.t_type = 1 union select t.*,         tf.*   templates t   join templates_fax tf on tf.t_id = t.t_id  t.t_type not in (0, 1)

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