The SQL IN clause is used when you are filtering data and you want to look for more than one value.
Let’s take a look at the following query:
select * from customer where customer_company = 'Dell' or customer_company='HP' or customer_company='Walmart';
This query says that we want all of the columns, from the company table, where the customer_company is either Dell, or HP, or Walmart.
Here are the results:
This query works great, but it means you have to type a lot more than you need to.
That is where the “IN” clause comes into play. Instead of typing “customer_company” 3 times like we did in the previous SQL Query, we can write the query as follows:
select * from customer where customer_company IN ('Dell','HP','Walmart');
The results of this query are the exact same as the results above.
Notice how much less typing I had to do. And, notice the syntax.
It goes column name (in this case customer_company), then you use the “IN” word, then you list all of the values in side of parenthesis and separated by commas.
That’s it. I often use the IN clause instead of a bunch of OR’s, because it is neater and easier for me to read.
As you start putting more complex queries together, it will be a lot easier to keep track of an IN clause instead of a bunch of OR statements.
Remember to put any question, comments, or other topics you would like for me to explain into the comment section below.