SQL basics: last ID, duplicate handling, GROUP BY/HAVING, and JOIN types

Notes

S Q L Most Asked Interview QuestionsFor Interviews SQL A D V A N C E D Concepts Everyone learns uniquely. What matters is your preparation and consistency. With this doc understand the major SQL concepts and ace your next interview. *Disclaimer* In SQL, you can find the last ID in a table using the MAX function along with the column that represents the ID. Assuming you have an "id" column in your table, you can use the following query: SQL SELECT MAX(id) AS last_id FROM your_table_name; This query selects the maximum (largest) value in the "id" column and aliases it as "last_id." The result will be a single row with the highest ID value in the specified table. Otherwise, in many SQL versions, we can use the following syntax: SQL SELECT id FROM your_table_name ORDER BY id DESC LIMIT 1; This query selects the maximum (largest) value in the "id" column and aliases it as "last_id." The result will be a single row with the highest ID value in the specified table. 01 Q u e s t i o n How do you find the last ID in a SQL table? 02 Q u e s t i o n How do you remove duplicates from a table? Using :DISTINCT SQL SELECT DISTINCT * FROM your_table; This will retrieve distinct rows from the table...