Best answer: How do I count distinct rows in SQL?

How do I get a distinct row count?

Distinct Counts

The COUNT(DISTINCT) function returns the number of rows with unique non-NULL values. Hence, the inclusion of the DISTINCT keyword eliminates duplicate rows from the count. Its syntax is: COUNT(DISTINCT expr,[expr…])

Can we use distinct with Count in SQL?

Yes, you can use COUNT() and DISTINCT together to display the count of only distinct rows. SELECT COUNT(DISTINCT yourColumnName) AS anyVariableName FROM yourTableName; … If you do not use DISTINCT, then COUNT() function gives the count of all rows.

How do I count rows in SQL without counting?

Count Rows of a table Without using Count() Function

  1. SELECT so.[name] as.
  2. , CASE WHEN si. indid between 1 and 254.
  3. THEN si.[name] ELSE NULL END.
  4. AS [Index Name]
  5. , si. indid, rows.
  6. FROM sys. sysindexes si.
  7. INNER JOIN sysobjects so.
  8. ON si. id = so. id.

Does Count distinct include NULL?

COUNT DISTINCT does not count NULL as a distinct value. COUNT(DISTINCT BY(col2) col1) counts col1 values for distinct col2 values; however, the distinct col2 values may include a single NULL as a distinct value.

What is the difference between count and distinct count?

Count would show a result of all records while count distinct will result in showing only distinct count. For instance, a table has 5 records as a,a,b,b,c then Count is 5 while Count distinct is 3.

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How do you count distinct?

The correct syntax for using COUNT(DISTINCT) is: SELECT COUNT(DISTINCT Column1) FROM Table; The distinct count will be based off the column in parenthesis. The result set should only be one row, an integer/number of the column you’re counting distinct values of.

How do I select distinct values in SQL?

How to use distinct in SQL?

  1. SELECT DISTINCT returns only distinct (different) values.
  2. DISTINCT eliminates duplicate records from the table.
  3. DISTINCT can be used with aggregates: COUNT, AVG, MAX, etc.
  4. DISTINCT operates on a single column.
  5. Multiple columns are not supported for DISTINCT.

How do I count rows in SQL Server?

SQL Server @@ROWCOUNT is a system variable that is used to return the number of rows that are affected by the last executed statement in the batch.

How do you count without group by?

4 Answers

  1. select a, count(*) as c from mytable group by a where c > 1; You need to replace where with having in this case, as follows:
  2. select a, count(*) as c from mytable group by a having c > 1; NB The following query form will also work:
  3. select * from ( select a, count(*) as c from mytable group by a ) where c > 1;