SQL 2 Tables

sql-inner

# ohatra
# table_1 (id, field_11, field_12)
# table_2 (id, field_21, field_22)

# de field_11 <-> field_21 ohatra
# eo amreo field 2 reo ohatra no misy ny liaison amle table 2

# de ohatra (field_12 x field_22) no tiana ho azo

select (t1.field_12 * t2.field_22) as `produit` from table_1 t1
inner join table_2 t2 on t2.field_21 = t1.field_11