SQL Programming
SQL Programming
February 5, 2025 at 05:55 PM
Most Asked SQL Interview Questions at MAANG Companies🔥🔥 Preparing for an SQL Interview at MAANG Companies? Here are some crucial SQL Questions you should be ready to tackle: 1. How do you retrieve all columns from a table? SELECT * FROM table_name; 2. What SQL statement is used to filter records? SELECT * FROM table_name WHERE condition; The WHERE clause is used to filter records based on a specified condition. 3. How can you join multiple tables? Describe different types of JOINs. SELECT columns FROM table1 JOIN table2 ON table1.column = table2.column JOIN table3 ON table2.column = table3.column; Types of JOINs: 1. INNER JOIN: Returns records with matching values in both tables SELECT * FROM table1 INNER JOIN table2 ON table1.column = table2.column; 2. LEFT JOIN: Returns all records from the left table & matched records from the right table. Unmatched records will have NULL values. SELECT * FROM table1 LEFT JOIN table2 ON table1.column = table2.column; 3. RIGHT JOIN: Returns all records from the right table & matched records from the left table. Unmatched records will have NULL values. SELECT * FROM table1 RIGHT JOIN table2 ON table1.column = table2.column; 4. FULL JOIN: Returns records when there is a match in either left or right table. Unmatched records will have NULL values. SELECT * FROM table1 FULL JOIN table2 ON table1.column = table2.column; 4. What is the difference between WHERE & HAVING clauses? WHERE: Filters records before any groupings are made. SELECT * FROM table_name WHERE condition; HAVING: Filters records after groupings are made. SELECT column, COUNT(*) FROM table_name GROUP BY column HAVING COUNT(*) > value; 5. How do you calculate average, sum, minimum & maximum values in a column? Average: SELECT AVG(column_name) FROM table_name; Sum: SELECT SUM(column_name) FROM table_name; Minimum: SELECT MIN(column_name) FROM table_name; Maximum: SELECT MAX(column_name) FROM table_name; Like this post if you need more 👍❤️ Hope it helps :)
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