Can I use distinct and GROUP BY together?

Can I use distinct and GROUP BY together?

Make a decision of which one is better in your query by checking the execution plans and determine the relative efficiency of queries that generate the same result set. Well, GROUP BY and DISTINCT have their own use. GROUP BY cannot replace DISTINCT in some situations and DISTINCT cannot take place of GROUP BY.

Can we use distinct and GROUP BY together in SQL?

You can use it together in SELECT …, COUNT(DISTINCT …)

no, you can drop the DISTINCT , it’s redundant.

group by delivers distinct results.

A few weeks back, I was browsing through some articles and came across some discussion about some special use-case for this.

Is it better to use distinct or GROUP BY?

In MySQL, DISTINCT seems a bit faster than GROUP BY if theField is not indexed. DISTINCT only eliminate duplicate rows but GROUP BY seems to sort them in addition.

What is the difference between GROUP BY and distinct in MySQL?

3 Answers. Well group by and distinct has its own use. Distinct is used to filter unique records out of the records that satisfy the query criteria. Group by clause is used to group the data upon which the aggregate functions are fired and the output is returned based on the columns in the group by clause.

Is GROUP BY or distinct faster?

DISTINCT is used to filter unique records out of all records in the table. It removes the duplicate rows. SELECT DISTINCT will always be the same, or faster than a GROUP BY.

Why is GROUP BY faster than distinct?

If one of them is faster, it’s going to be DISTINCT . This is because, although the two are the same, a query optimizer would have to catch the fact that your GROUP BY is not taking advantage of any group members, just their keys. DISTINCT makes this explicit, so you can get away with a slightly dumber optimizer.

Is GROUP BY and distinct same?

Distinct is used to find unique/distinct records where as a group by is used to group a selected set of rows into summary rows by one or more columns or an expression. The group by gives the same result as of distinct when no aggregate function is present.

Which is better distinct or GROUP BY in Oracle?

While DISTINCT better explains intent, and GROUP BY is only required when aggregations are present, they are interchangeable in many cases. GROUP BY can (again, in some cases) filter out the duplicate rows before performing any of that work.

What is GROUP BY mysql?

The MYSQL GROUP BY Clause is used to collect data from multiple records and group the result by one or more column. It is generally used in a SELECT statement. You can also use some aggregate functions like COUNT, SUM, MIN, MAX, AVG etc. on the grouped column.

How can we make a group more efficient?

GROUP BY performs better if you keep the number of grouping columns small. Avoid grouping redundant columns by using set functions. When you’re grouping joined tables, reduce before you expand. You can make a join happen late by replacing it with a set operator.

When to use SELECT DISTINCT vs group by?

SELECT DISTINCT can be used to give distinct values. Use it to remove duplicate records and it can be used with aggregate function as well. For example: Select group by can be used to get data from different columns and group into one or more column.

How is the group by clause used in MySQL?

The GROUP BY clause groups the returned record set by one or more columns. You specify which columns the result set is grouped by. The above query selects all records from the users database table, then groups them by the address field. MySQL HAVING Clause is used with GROUP BY clause. It always returns the rows where condition is TRUE.

Why do we use distinct and count together in SQL?

I would do something like this: This allows you to see how many of each distinct productid ID is associated with the keyword. for another answer about this type of question this is my another answer for getting count of product base on product name distinct like this sample below: Isn’t it better with a group by? Something like:

How does the ORDER BY clause work in MySQL?

The above query selects all records from the users database table, then orders them by the first_name field in descending order. The GROUP BY clause groups the returned record set by one or more columns. You specify which columns the result set is grouped by.