How to Use Distinct in SQL
Ever wanted to know how many unique values there are in a particular column of your database? Well, you're in luck! SQL has a handy way of counting distinct values that can help you get the answer you need. 🤓
The Solution
The solution is to use the COUNT(DISTINCT) function. This function takes a single argument, which is the column you want to count the distinct values of. For example, if you wanted to count the distinct values in the name column of your database, you would use the following query:
SELECT COUNT(DISTINCT name) FROM table_name;
Examples
Let's look at a few examples of how this function can be used. Suppose you have a table called users with the following data:
name | age |
---|---|
John | 25 |
Jane | 30 |
John | 25 |
Bob | 20 |
If you wanted to count the number of distinct names in this table, you would use the following query:
SELECT COUNT(DISTINCT name) FROM users;
This query would return the result 3, since there are three distinct names in the table (John, Jane, and Bob).
Additional Info
The COUNT(DISTINCT) function is supported by most major databases, including MySQL, PostgreSQL, and SQL Server. However, the syntax may vary slightly depending on the database you are using. For more information, check out the documentation for your particular database. 🤓