where condition check a field has data or not if exist

lejo

in where condition emplyee details is exist in a table eg:table1 then take data from table1 .employee data not exists then take data from another table eg:table2 .

How to do this in where condition

6 Replies

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Rajeev Kumar3y ago
Hi you use with EXISTS

IF Exists (select count(1) from table1)

begin

select * from table1 end else

begin select * from table2 end
+1

Naimish Makwana3y ago

You can use below query for the same.

SELECT COALESCE(table1.employee_details, table2.employee_details) AS employee_details
FROM table1
LEFT JOIN table2 ON table1.employee_id = table2.employee_id

Thanks

Jignesh Kumar3y ago
Hello Lejo,

You can use except to achieve your requirement,
```
SELECT id, name FROM Table1
Except
SELECT id, name FROM Table2
```
+2
Aradhana Tripathi3y ago
You can do this simply using SQL left join clause.
```
select * from table1 left join  table2 
on table1.id = table2.id
where table2.id is null;
```
+2
Aravind Govindaraj3y ago
In this case, you can approach if exists a statement or else creates a view internally to apply the union to all required tables. just get it from there....
+2

Sachin Singh3y ago

IF Exists (select count(1) from table1)
begin
select * from table1
end
else
begin
select * from table2
end