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brian mk
brian mk

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25 SQL tricks for beginners.

Certainly! Here are 25 SQL tricks for beginners:

  1. SELECT Statement: Retrieve data from a database table using the SELECT statement.

  2. WHERE Clause: Filter data based on specific conditions using the WHERE clause in conjunction with the SELECT statement.

  3. DISTINCT Keyword: Retrieve unique values from a column using the DISTINCT keyword.

  4. ORDER BY Clause: Sort the result set in ascending or descending order using the ORDER BY clause.

  5. LIMIT Clause: Limit the number of rows returned by a query using the LIMIT clause (syntax may vary across different database systems).

  6. JOIN: Combine rows from multiple tables based on a related column using JOIN operations such as INNER JOIN, LEFT JOIN, RIGHT JOIN, or FULL JOIN.

  7. GROUP BY Clause: Group rows based on a specific column(s) and perform aggregate functions like COUNT, SUM, AVG, MAX, or MIN on grouped data.

  8. HAVING Clause: Filter the result set based on conditions applied to the groups created by the GROUP BY clause.

  9. INSERT Statement: Insert new data into a table using the INSERT statement.

  10. UPDATE Statement: Modify existing data in a table using the UPDATE statement.

  11. DELETE Statement: Remove data from a table using the DELETE statement.

  12. IN Operator: Check if a value exists within a set of values using the IN operator.

  13. BETWEEN Operator: Check if a value falls within a specific range using the BETWEEN operator.

  14. LIKE Operator: Perform pattern matching using the LIKE operator with wildcard characters (% and _).

  15. NULL Values: Handle NULL values in the database using IS NULL or IS NOT NULL operators.

  16. COUNT() Function: Count the number of rows in a table or the number of occurrences of a specific value using the COUNT() function.

  17. SUM() Function: Calculate the sum of values in a column using the SUM() function.

  18. AVG() Function: Calculate the average of values in a column using the AVG() function.

  19. MAX() Function: Retrieve the maximum value from a column using the MAX() function.

  20. MIN() Function: Retrieve the minimum value from a column using the MIN() function.

  21. Alias: Assign a temporary name to a table or column using the AS keyword to improve readability.

  22. Subqueries: Use a query within another query to perform complex operations or retrieve data from multiple tables.

  23. EXISTS Keyword: Check the existence of specific data in a subquery using the EXISTS keyword.

  24. UNION Operator: Combine the result sets of multiple SELECT statements into a single result set using the UNION operator.

  25. CASE Statement: Perform conditional logic within a query using the CASE statement to create custom columns or apply specific operations based on conditions.

Top comments (2)

yet_anotherdev profile image
Lucas Barret • Edited

Really cool, it is really helpful for beginners I think. Did you know that IN(value1,value2) is the same has =ANY(ARRAY[value1,value2]). Actually when you look at the execution plan this what it is display

rozhnev profile image
Slava Rozhnev

The article can be improved by examples for each statement.
You can use for share SQL