# WHERE in T-SQL

WHERE in T-SQL: WHERE in T-SQL: an overview, Types of Filters, Using Multiple Condition Filters.

Updated: November 3, 2026

1. [WHERE in T-SQL: an overview](https://www.ask-codey.com/lessons/where-in-t-sql-an-overview) (Novice): A WHERE clause keeps only the rows that match a condition, such as the customers in one country.
2. [Types of Filters](https://www.ask-codey.com/lessons/where-in-t-sql-types-of-filters) (Apprentice): Filter numbers and dates with comparison operators, text with LIKE patterns, lists with IN, ranges with BETWEEN, and missing values with IS NULL.
3. [Using Multiple Condition Filters](https://www.ask-codey.com/lessons/where-in-t-sql-using-multiple-condition-filters) (Apprentice): Combine conditions in a WHERE clause with AND, OR and NOT, and use parentheses so they're checked the way you mean.

Source: https://www.ask-codey.com/courses/csharp-full-stack-bootcamp/topics/where-in-t-sql