614.7K
CHOrder : FROM → JOIN → WHERE → GROUP BY → HAVING → SELECT → ORDER BY → LIMIT
Explanation:
1. FROM ✅
• SQL first decides which tables it will use.
• It loads the data from those tables.
2. JOIN✅
• If your query has joins, SQL will next connect the tables based on join conditions.
3. WHERE✅
• Filters rows.
• Removes rows that do not meet your conditions.
4. GROUP BY✅
• Groups remaining rows into small buckets based on columns.
• Required when you use aggregate functions: COUNT(), SUM(), AVG() etc.
5. HAVING✅
• Works like WHERE, but after grouping.
• Filters groups instead of individual rows.
6. SELECT✅
• Now SQL picks which columns or calculations to show.
• This is where alias names are applied.
7. ORDER BY✅
• Sorts the final result (ascending / descending).
8. LIMIT / TOP✅
• Finally, SQL returns only the requested number of rows.
(SQL, SQL Query, SQL Execution order, SQL interview questions, SQL database, relational database, backend engineering, system design basics)
#sql #interview #programmingtips #systemdesign #data
@chhavi_maheshwari_
