I am getting error while executing the following query.
SELECT COUNT(distinct *) AS "total unique records" FROM table
Please help me to resolve this issue
Because * is not allowed there. If you want to do this, use a subquery:
select count(*)
from (select distinct t.*
from t
) t;
You probably want :
select count(*)
from (select distinct t.*
from table t
) t;
Use this code too count row
SELECT COUNT(*) AS TotalRecords FROM table
AND use that too count row and return order columns
SELECT COUNT(*) OVER() AS TotalRecords,* FROM table
Related
What is the best way to get count of rows and distinct rows in a single query?
To get distinct count we can use subquery like this:
select count(*) from
(
select distinct * from table
)
I have 15+ columns and have many duplicates rows as well and I want to calculate count of rows as well as distinct count of rows in one query.
More if I use this
select count(*) as Rowcount , count(distinct *) as DistinctCount from table
This will not give accurate results as count(distinct *) doesn't work.
Why don't you just put the subquery inside another query?
select count(*),
(select count(*) from (select distinct * from table))
from table;
create table tbl
(
col int
);
insert into tbl values(1),(2),(1),(3);
select count(*) as distinct_count, sum(sum) as all_count
from (
select count(col) sum from tbl group by col
)A
I think I have understood what you are looking for. You need to use some window function. So, you query should be look like =>
Select COUNT(*) OVER() YourRowcount ,
COUNT(*) OVER(Partition BY YourColumnofGroup) YourDistinctCount --Basic of the distinct count
FROM Yourtable
NEW Update
select top 1
COUNT(*) OVER() YourRowcount,
DENSE_RANK() OVER(ORDER BY YourColumn) YourDistinctCount
FROM Yourtable ORDER BY TT DESC
Note: This code is written sql server. Please check the code and let me know.
Good morning
I tried and tried to understand why this Query gives the usual error on Group By. I would like to find the duplicate lines and delete them. I found this query on Microsoft's MSDN but despite this it keeps giving me this error on Group By.
The main table has 3 fields "Id, Item, Description", the table name is "tlbDescription", this query should in theory create a table named "duplicate_table" insert the duplicate values inside the "duplicate_table", then delete the values from table "tlbDescription" and finally delete the table "duplicate_table".
If someone can kindly give me a hand
Thank you
Fabrizio
This is the query:
SELECT DISTINCT *
INTO duplicate_table
FROM [tlbDescrizione]
GROUP BY [Articolo]
HAVING COUNT([Articolo]) > 1
DELETE [tlbDescrizione]
WHERE [Articolo] IN (SELECT [Articolo] FROM duplicate_table)
INSERT [tlbDescrizione]
SELECT * FROM duplicate_table
DROP TABLE duplicate_table
This query doesn't make sense:
SELECT DISTINCT *
INTO duplicate_table
FROM [tlbDescrizione]
GROUP BY [Articolo]
HAVING COUNT([Articolo]) > 1;
It is selecting all columns but is an aggregation query because of the GROUP BY. Hence, the SELECT columns are inconsistent with the GROUP BY columns and you get an error.
If you want all the columns then you can use window functions:
SELECT DISTINCT *
INTO duplicate_table
FROM (SELECT d.*, COUNT(*) OVER (PARTITION BY d.Articolo) as cnt
FROM tlbDescrizione d
) d
WHERE cnt > 1;
Or, if you want only the ids:
SELECT Articolo
INTO duplicate_table
FROM tlbDescrizione
GROUP BY [Articolo]
HAVING COUNT(*) > 1;
I don't understand why I can't use this in my code :
SELECT MAX(SMTHNG), COUNT(MAX(SMTHNG))
FROM SomeTable;
Searched for an answer but didn't find it in documentation about these aggregate functions.
Also I get an SQL-compiler error "Invalid column name "SMTHNG"".
You want to know what the maximum SMTHNG in the table is with:
SELECT MAX(SMTHNG) FROM SomeTable;
This is an aggregation without GROUP BY and hence results in one single row containing the maximum SMTHNG.
Now you also want to know how often this SMTHNG occurs and you add COUNT(MAX(SMTHNG)). This, however, does not work, because you can not aggregate an aggregate directly.
This doesn't work either:
SELECT ANY_VALUE(max_smthng), COUNT(*)
FROM (SELECT MAX(smthng) AS max_smthng FROM sometable) t;
because the sub query only contains one row, so it's too late to count.
So, either use a sub query and select from the table again:
SELECT ANY_VALUE(smthng), COUNT(*)
FROM sometable
WHERE smthng = (SELECT MAX(smthng) FROM sometable);
Or count per SMTHNG before looking for the maximum. Here is how to get the counts:
SELECT smthng, COUNT(*)
FROM sometable
GROUP BY smthng;
And the easiest way to get the maximum from this result is:
SELECT TOP(1) smthng, COUNT(*)
FROM sometable
GROUP BY smthng
ORDER BY COUNT(*) DESC;
First of all, please read my comment.
Depending on what you're trying to achieve, the statement have to be changed.
If you want to count the highest values in SMTHNG field, you may try this:
SELECT T1.SMTHNG, COUNT(T1.SMTHNG)
FROM SomeTable T1 INNER JOIN
(
SELECT MAX(SMTHNG) AS A
FROM SomeTable
) T2 ON T1.SMTHNG = T2.A
GROUP BY T1.SMTHNG;
use cte like below or subquery
with cte as
(
select count(*) as cnt ,col from table_name
group by col
) select max(cnt) from cte
you can not use double aggregate function at a time on same column
I want to count id_r and then return the maxim value of count using
MAX(COUNT(id_r))
but shows me this error
the error
Thanks :)
You can only use one aggregation function at a time.
The ANSI standard way to do what you want is:
select count(*)
from t
group by ?
order by count(*) desc
fetch first 1 row only;
Or alternatively a subquery:
select max(cnt)
from (select count(*) as cnt
from t
group by ?
) x;
Note that you want a group by of something, perhaps id_r.
Try this:
SELECT MAX(e1) as Expr1 FROM (
SELECT COUNT(id_r) as e1
FROM Angajat) as t1
COUNT(id_r) wil return only 1 result since there is no group by clause. Hence, there is no use of max.
You need to add a group by clause in subquery:
SELECT MAX(e1) as Expr1 FROM (
SELECT column1, COUNT(id_r) as e1
FROM Angajat
GROUP BY column1
) as t1
If i perform a standard query in SQLite:
SELECT * FROM my_table
I get all records in my table as expected. If i perform following query:
SELECT *, 1 FROM my_table
I get all records as expected with rightmost column holding '1' in all records. But if i perform the query:
SELECT *, COUNT(*) FROM my_table
I get only ONE row (with rightmost column is a correct count).
Why is such results? I'm not very good in SQL, maybe such behavior is expected? It seems very strange and unlogical to me :(.
SELECT *, COUNT(*) FROM my_table is not what you want, and it's not really valid SQL, you have to group by all the columns that's not an aggregate.
You'd want something like
SELECT somecolumn,someothercolumn, COUNT(*)
FROM my_table
GROUP BY somecolumn,someothercolumn
If you want to count the number of records in your table, simply run:
SELECT COUNT(*) FROM your_table;
count(*) is an aggregate function. Aggregate functions need to be grouped for a meaningful results. You can read: count columns group by
If what you want is the total number of records in the table appended to each row you can do something like
SELECT *
FROM my_table
CROSS JOIN (SELECT COUNT(*) AS COUNT_OF_RECS_IN_MY_TABLE
FROM MY_TABLE)