sql - join one table if condition met otherwise from another table -

i want know sql query following condition

i have 3 tables, table 1 want data, second table1mapping , third master table.

i want data table1mapping if related data exists otherwise master table , table 1.

table 1 common.

for example:

table 1:

id    name 1     abc 

table1mapping:

table1id    country    code 1                   958 2           ind        89 

master

country     code uk          87          56 ind         45 

user can select multiple countries. if selects , ind code should table1mapping , ind should master there no data id 1 , us.

code may different in both tables.

you didn't provide schema created fantasy data show how can like.

description: use 2 left joins in combination coalesce, give first element not null.

declare @tab1 table (     id int )  declare @tabmapping table (     id int,     anycol varchar(100) )  declare @tabmaster table (     id int,     anycol varchar(100) )  insert @tab1 (id) values (1),(2),(3),(4),(5),(6) insert @tabmapping (id,anycol) values (1,'a'),(2,'b'),(3,'c') insert @tabmaster (id,anycol) values (3,'c'),(4,'d'),(5,'e')  select  t1.id,         coalesce(map.anycol,mas.anycol,'no data id')    @tab1 t1         left join @tabmapping map on t1.id = map.id         left join @tabmaster mas on t1.id = mas.id 

what should care about: if data in mapping , master? if data not in mapping nor master! (in example if nothing found in mapping , master default value ("no data id") shown. if data exist in both tables value come mapping table it's first argument in coalesce()...