AND as useful as all that is, we can really start to pile it on when we introduce our first logical operator AND.

When we use the WHERE clause to filter results, a single condition may not be sufficient for our needs. By using the AND logical operator, we can combine multiple conditions that all need to be true for a record to be included in the results. For example, consider a scenario where we want to find Opportunities that are both high-value and currently in the negotiation stage. Here's how we can do that:

SELECT Name, Amount, StageName
FROM Opportunity 
WHERE Amount > 100000 AND StageName = 'Negotiation/Review'

Suppose we want to filter Opportunities to find those that are not new customers, have a probability of winning higher than 50%, and are not yet closed. We would use the AND logical operator to ensure all these conditions are met simultaneously. Here’s how that query might look:

SELECT Name, Type, Probability, IsClosed
FROM Opportunity  
WHERE Type != 'New Customer' AND Probability > 50 AND IsClosed = false

Lastly, while tempting, we don't necessarily need to show these columns in the SELECT output for which we have specified the condition for. We always know what the value will be in some cases.

SELECT Name, ExpectedRevenue
FROM Opportunity  
WHERE StageName = 'Negotiation/Review' AND Type = 'Existing Customer - Upgrade' AND ExpectedRevenue > 100000