The main difference between WHERE and HAVING clause is that the WHERE clause allows you to filter data from specific rows (individual rows) from a table based on certain conditions. In contrast, the HAVING clause allows you to filter data from a group of rows in a query based on conditions involving aggregate values.

WHERE Clause

WHERE Clause is used to filter the records from the table or used while joining more than one table. Only those records will be extracted who are satisfying the specified condition in the WHERE clause.

SELECT user_name, Age FROM users WHERE Age >=25
HAVING Clause

HAVING Clause is used to filter the records from the groups based on the given condition in the HAVING Clause.

SELECT Age, COUNT(user_id) AS No_of_Users FROM users GROUP BY Age HAVING COUNT(user_id) > 1
Difference Between Where and Having Clause in SQL
WHERE ClauseHAVING Clause
Filters rows before groups are aggregated.Filters groups after the aggregation process.
WHERE Clause can be used without GROUP BY ClauseHAVING Clause can be used with GROUP BY Clause
WHERE Clause implements in row operationsHAVING Clause implements in column operation
WHERE Clause cannot contain aggregate functionHAVING Clause can contain aggregate function
WHERE Clause can be used with SELECT, UPDATE, DELETE statement.HAVING Clause can only be used with SELECT statement.
WHERE Clause is used before GROUP BY ClauseHAVING Clause is used after GROUP BY Clause
WHERE Clause is used with single row function like UPPER, LOWER etc.HAVING Clause is used with multiple row function like SUM, COUNT etc.
Conclusion

While both WHERE and HAVING clauses are used for filtering data in SQL queries, they serve different purposes and are applied at different stages of query execution. Understanding their distinctions is crucial for writing efficient and effective SQL queries.