What is the difference between WHERE and having clause?

A HAVING clause is like a WHERE clause, but applies only to groups as a whole (that is, to the rows in the result set representing groups), whereas the WHERE clause applies to individual rows.

What is the difference between HAVING and WHERE clause Class 12?

Difference between WHERE and HAVING clause

The WHERE clause is used in the selection of rows according to given conditions whereas the HAVING clause is used in column operations and is applied to aggregated rows or groups.

What is the purpose of WHERE and HAVING clause?

The HAVING Clause enables you to specify conditions that filter which group results appear in the results. The WHERE clause places conditions on the selected columns, whereas the HAVING clause places conditions on groups created by the GROUP BY clause.

Can we use WHERE clause instead of HAVING?

To sum up this tutorial, remember the simple rule: If you need to work with aggregate functions, use GROUP BY and HAVING. And if you need to apply general conditions, use WHERE.

Which is better HAVING or WHERE?

The main difference between the WHERE and HAVING clauses comes when used together with the GROUP BY clause. In that case, WHERE is used to filter rows before grouping, and HAVING is used to exclude records after grouping.

Difference Between WHERE and HAVING Clause | SQL Tutorial | Where vs Having

Which is faster HAVING or WHERE?

SQL Standard says that WHERE restricts the result set before returning rows and HAVING restricts the result set after bringing all the rows. So WHERE is faster.

What is the difference between union and union all?

The UNION ALL command is equal to the UNION command, except that UNION ALL selects all values. The difference between Union and Union all is that Union all will not eliminate duplicate rows, instead it just pulls all rows from all tables fitting your query specifics and combines them into a table.

Can I use HAVING instead of WHERE in SQL?

To be valid the having clause can only compare results of aggregated functions or column part of the group by. In conclusion, the difference between WHERE and HAVING are: WHERE is used to filter records before any groupings take place. HAVING is used to filter values after they have been groups.

Can you have two WHERE clauses in SQL?

You can specify multiple conditions in a single WHERE clause to, say, retrieve rows based on the values in multiple columns. You can use the AND and OR operators to combine two or more conditions into a compound condition.

What is the use of WHERE clause in SQL?

The WHERE clause is used to filter records. It is used to extract only those records that fulfill a specified condition.

What is the difference between GROUP BY and HAVING clause in SQL?

The HAVING clause is used instead of WHERE with aggregate functions. While the GROUP BY Clause groups rows that have the same values into summary rows. The having clause is used with the where clause in order to find rows with certain conditions. The having clause is always used after the group By clause.

Why WHERE clause is not used with aggregate functions?

You cannot use aggregate functions in a WHERE clause or in a JOIN condition. However, a SELECT statement with aggregate functions in its SELECT list often includes a WHERE clause that restricts the rows to which the aggregate is applied.

What is difference between truncate and delete command?

Delete and truncate both commands can be used to delete data of the table. Delete is a DML command whereas truncate is DDL command. Truncate can be used to delete the entire data of the table without maintaining the integrity of the table. On the other hand , delete statement can be used for deleting the specific data.

What is difference between order by and GROUP BY?

Key Differences between GROUP BY and ORDER BY

The Group By clause is used to group data based on the same value in a specific column. The ORDER BY clause, on the other hand, sorts the result and shows it in ascending or descending order. It is mandatory to use the aggregate function to use the Group By.

IS null is not null?

The IS NULL condition is satisfied if the column contains a null value or if the expression cannot be evaluated because it contains one or more null values. If you use the IS NOT NULL operator, the condition is satisfied when the operand is column value that is not null, or an expression that does not evaluate to null.

Is null statement in SQL?

Description. The IS NULL condition is used in SQL to test for a NULL value. It returns TRUE if a NULL value is found, otherwise it returns FALSE. It can be used in a SELECT, INSERT, UPDATE, or DELETE statement.

What is XOR SQL?

MySQL XOR operator checks two operands (or expressions) and returns TRUE if one or the other but not both is TRUE. Syntax: XOR. MySQL Logical XOR returns a NULL when one of the operands is NULL.

What is the difference between char and varchar?

Difference between CHAR and VARCHAR datatypes

In CHAR, If the length of string is less than set or fixed length then it is padded with extra memory space. In VARCHAR, If the length of string is less than set or fixed length then it will store as it is without padded with extra memory spaces.

What is the difference between an inner and outer join?

The biggest difference between an INNER JOIN and an OUTER JOIN is that the inner join will keep only the information from both tables that's related to each other (in the resulting table). An Outer Join, on the other hand, will also keep information that is not related to the other table in the resulting table.

What is a subquery in SQL?

About subqueries

A subquery is a query that appears inside another query statement. Subqueries are also referred to as sub- SELECT s or nested SELECT s. The full SELECT syntax is valid in subqueries.

What is difference between stored procedure and function?

The function must return a value but in Stored Procedure it is optional. Even a procedure can return zero or n values. Functions can have only input parameters for it whereas Procedures can have input or output parameters. Functions can be called from Procedure whereas Procedures cannot be called from a Function.

What is the difference between MINUS and intersect?

INTERSECT compares the data between tables and returns only the rows of data that exist in both tables. MINUS compares the data between tables and returns the rows of data that exist only in the first table you specify.

What is the difference between Union and intersection?

Both union and intersection are the two fundamental operations through which sets can be combined and related to each other. In terms of set theory, union is the set of all the elements that are in either set, or in both, whereas intersection is the set of all distinct elements that belong to both the sets.

What is self join in SQL?

A self join is a regular join, but the table is joined with itself.

What is trigger in SQL?

A trigger is a special type of stored procedure that automatically runs when an event occurs in the database server. DML triggers run when a user tries to modify data through a data manipulation language (DML) event. DML events are INSERT, UPDATE, or DELETE statements on a table or view.