- Can we have count and distinct together in SQL?
- Can we use sum and count together in SQL?
- How do I count unique values in SQL?
- Is group by or distinct faster?
- How do I select distinct rows in SQL?
- What is difference between Count and Sum?
- How do I count a column in SQL?
- Is group by better than distinct?
- What is difference between group by and distinct?
- What is difference between unique and distinct?
- What is Count * in SQL?
- How do I count rows in SQL?
- Which is faster count (*) or Count 1?
- Can we use distinct and group by together?
- Does Count distinct count nulls?
- How do you select distinct rows in SQL without using distinct?
- How do you use distinct?
- Can we use two group by in same query?

## Can we have count and distinct together in SQL?

We can use SQL Count Function to return the number of rows in the specified condition.

The syntax of the SQL COUNT function: COUNT ([ALL | DISTINCT] expression); By default, SQL Server Count Function uses All keyword..

## Can we use sum and count together in SQL?

SUM() and COUNT() functions SUM of values of a field or column of a SQL table, generated using SQL SUM() function can be stored in a variable or temporary column referred as alias. The same approach can be used with SQL COUNT() function too.

## How do I count unique values in SQL?

To count the number of different values that are stored in a given column, you simply need to designate the column you pass in to the COUNT function as DISTINCT . When given a column, COUNT returns the number of values in that column. Combining this with DISTINCT returns only the number of unique (and non-NULL) values.

## 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.

## How do I select distinct rows in SQL?

To do this, you use the SELECT DISTINCT clause as follows: SELECT DISTINCT column_name FROM table_name; The query returns only distinct values in the specified column. In other words, it removes the duplicate values in the column from the result set.

## What is difference between Count and Sum?

What is the difference between SUM and COUNT? Very simply, SUM calculates a total for a number of cells or values, so it’s answering the question: HOW MUCH? Or, WHAT IS THE TOTAL? COUNT tells you HOW MANY cells meet a certain condition.

## How do I count a column in SQL?

SQL COUNT() FunctionSQL COUNT(column_name) Syntax. The COUNT(column_name) function returns the number of values (NULL values will not be counted) of the specified column: … SQL COUNT(*) Syntax. The COUNT(*) function returns the number of records in a table: … SQL COUNT(DISTINCT column_name) Syntax.

## Is group by better than distinct?

While DISTINCT better explains intent, and GROUP BY is only required when aggregations are present, they are interchangeable in many cases. Same operators, same number of reads, negligible differences in CPU and total duration (they take turns “winning”).

## What is difference between group by and distinct?

DISTINCT is used to filter unique records out of the records that satisfy the query criteria. The “GROUP BY” clause is used when you need to group the data and it should be used to apply aggregate operators to each group.

## What is difference between unique and distinct?

The main difference between unique and distinct is that UNIQUE is a constraint that is used on the input of data and ensures data integrity. While DISTINCT keyword is used when we want to query our results or in other words, output the data.

## What is Count * in SQL?

In SQL, count (*) does not take parameters and returns the total number of rows in a particular table. The difference between COUNT (*) and COUNT (ALL) is that COUNT (*) also counts NULL values and duplicates but COUNT (ALL) does count only unique and non-null values.

## How do I count rows in SQL?

Counting all of the Rows in a Table. To counts all of the rows in a table, whether they contain NULL values or not, use COUNT(*). That form of the COUNT() function basically returns the number of rows in a result set returned by a SELECT statement.

## Which is faster count (*) or Count 1?

According to this theory COUNT(*) takes all columns to count rows and COUNT(1) counts using the first column: Primary Key. Thanks to that COUNT(1) is able to use index to count rows and it’s much faster.

## Can we use distinct and group by together?

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. … Select group by can be used to get data from different columns and group into one or more column. This can also be applied with aggregate function.

## Does Count distinct count nulls?

COUNT(expression) like all aggregate functions, can take an optional DISTINCT clause. The DISTINCT clause counts only those columns having distinct (unique) values. COUNT DISTINCT does not count NULL as a distinct value. … The ALL keyword counts all non-NULL values, including all duplicates.

## How do you select distinct rows in SQL without using distinct?

You can use GROUP BY to select distinct values in SQL without using the DISTINCT keyword….Here’s a solution that does not use the DISTINCT keyword:SELECT t1. … FROM MyTable AS t1.JOIN (SELECT product, consumer FROM MyTable GROUP BY product, consumer)AS t2 ON t1. … GROUP BY t1.

## How do you use distinct?

SQL SELECT DISTINCT Statement SELECT DISTINCT returns only distinct (i.e. different) values. The DISTINCT keyword eliminates duplicate records from the results. DISTINCT can be used with aggregates: COUNT, AVG, MAX, etc. It operates on a single column.

## Can we use two group by in same query?

type can be only either debit or credit and instrument can be any method like credit card etc. What I need is to get a query which select year, month,type, instrument and the sum of ‘amount’ grouped by type and instrument as well as sum of income grouped by year and month.