create table t1 (
phone text
);
insert into t1 values ('123456789'), ('987654321');
create table t2 (
phone text
);
insert into t2 values ('123456789'), ('987654321');
create table t3 (
phone text
);
insert into t3 values ('123456789'), ('987654321');
select 't1', phone from t1 where phone = '987654321'
union all select 't2', phone from t2 where phone = '987654321'
union all select 't3', phone from t3 where phone = '987654321'