Can You Have Multiple WHERE Clauses in SQL

Technically the answer is yes, it is possible to have multiple WHERE clauses in a SQL statement. For example, if you are using a subquery, you can certainly employ a WHERE clause within the subquery, and then again in the outer query. Another example is when you are combining two SQL statements with a UNION / UNION ALL / INTERSECT / MINUS. In this case, both SQL statements can have their own WHERE clause.

However, notice in each of those cases there are also multiple SELECT statements as well, and each WHERE is associated with a single SELECT. In fact, in a SELECT statement, there can only be a single WHERE clause. This also applies to DELETE and UPDATE statements as well.

Usually when people ask this question, though, the concern is not really whether it’s possible to have multiple WHERE clauses in a SQL statement, but whether it’s possible to specify multiple conditions in a SQL statement. The answer to this question is yes. You would do this using a single WHERE statement. Assuming there are two conditions and you want both of them to be true, you can use AND to connect the two conditions. If you want either one of them to be true, you can use OR.

While it is possible to use a subquery with multiple WHERE clauses to specify multiple conditions,

-- This query has two WHERE clauses

this is not an efficient query to use. A better way to achieve the same result is as follows:

WHERE REGION = 'EAST' and YEAR = 2021;