SQL- |
SELECT BY ID_m, prm1, prm2, prm3 FROM table0 GROUP BY ID_m;
SELECT BY ID_m, A1, A2, A3 FROM table1 GROUP BY ID_m;
SELECT BY ID_m, B1, B2, B3 FROM table2 GROUP BY ID_m;
https://www.sql.ru/forum/1312050/sgruppirovat-po-kluchu-rezultaty-neskolkih-odnotipnyh-sql-zaprosov