Group by display row with highet value column - mysql

I have a table opname like this:
I want to select table opname with group by based id_barang and I want to display the row with the highest id of group by result.
I wrote query like this
SELECT
MAX(id), id_barang, tgl, ket, kondisi
FROM
`opname`
GROUP BY
id_barang
but why value of columns tgl, ket, kondisi it's not match with max(id) - how to fix that? I want to display row with the highest id of group by result

You can use the following using a sub-query:
SELECT id, id_barang, tgl, ket, kondisi FROM `opname` WHERE id IN (
SELECT MAX(id) FROM `opname` GROUP BY id_barang
)
With the inner SELECT you get all the maximum IDs of the grouped result. The outer SELECT selects all rows from your original table with all these IDs.

Your current query is not far off, except that it attempts to select non aggregate columns while using GROUP BY. This doesn't make logical sense, because it isn't clear which values should be chosen for each id_barang group. But if we join the opname table to your current query as a subquery, then we can identify the records you want to retain.
SELECT t1.*
FROM opname t1
INNER JOIN
(
SELECT id_barang, MAX(id) AS max_id
FROM opname
GROUP BY id_barang
) t2
ON t1.id_barang = t2.id_barang AND -- retain only MAX(id) records
t1.id = t2.max_id -- for each barang_id

Related

Count Distinct on multiple values within same column in SQL Aggregation

Objective:
I wanted to show the number of distinct IDs for any combination selected.
In the below example, I have data at a granular level: ID level data.
I wanted to show the number of distinct IDs for each combination.
For this, I use count distinct which will give me '1' for the below combinations.
But let's say if I wanted to find the number of IDs who made both E-commerce and Face to face transactions, in that case, if I just use this data, I would be showing the sum of E-comm and Face to face and the result would be '2' instead of '1'.
And this is not limited to Ecom/Face to face. I wanted to apply the same logic for all columns.
Please let me know if you have any other alternative approach to address this issue.
First aggregate in your table to get the distinct ids for each TranType:
SELECT TranType, COUNT(DISTINCT id) counter_distinct
FROM tablename
GROUP BY TranType
and then join to the table:
SELECT t.*, g.counter_distinct
FROM tablename t
INNER JOIN (
SELECT TranType, COUNT(DISTINCT id) counter_distinct
FROM tablename
GROUP BY TranType
) g ON g.TranType = t.TranType
Or use a correlated subquery:
SELECT t1.*,
(SELECT COUNT(DISTINCT t2.id) FROM tablename t2 WHERE t2.TranType = t1.TranType) counter_distinct
FROM tablename t1
But let's say if I wanted to find the number of IDs who made both E-commerce and Face to face transactions, in
You can get the list of ids using:
select id
from t
where tran_type in ('Ecomm', 'Face to face')
group by id
having count(distinct tran_type) = 2;
You can get the count using a subquery:
select count(*)
from (select id
from t
where tran_type in ('Ecomm', 'Face to face')
group by id
having count(distinct tran_type) = 2
) i;

MySQL take rows and override ones without user_id

I have table like this one:
I would like to all rows, but if there is user_id 5 if this case, override other rows which have no user_id.
I tried both with MAX(user_id) and GROUP BY country_name, but it still returns, wrong results.
Final result I'm expecting:
Try this;)
select t1.*
from yourtable t1
inner join (
select max(user_id) as user_id, country_name from yourtable group by country_name
) t2 on t1.country_name = t2.country_name and t1.user_id = t2.user_id
This is just a solution based on your sample data. If you have a variety of user_id, it should be more different.
As of SQL Select only rows with Max Value on a Column you can easily get rows with max value on a column by using both MAX(column) and GROUP BY other_column in one statement.
But if you want to select other columns too, you have to this in a subquery like in the following example:
SELECT a.*
FROM YourTable a
INNER JOIN (
SELECT country_name, MAX(user_id) user_id
FROM YourTable
GROUP BY country_name
) b ON a.country_name = b.country_name AND a.user_id = b.user_id

How to select * from table when group by?

select
OrderNo,
Sum(QtyIn) as QuantityIn,
Sum(QtyOut) as QuantityOut
from
tbl_Assign
group by
OrderNo
I want to select * from table also group by from table. How to do it?
To group by on all columns with a sum you cannot use *, you have to list all of the columns out and every column that isn't a function like Sum must be included in the group by.
So if you have other fields in your database such as OrderName, OrderedBy you can perform a group by like this:
Select
OrderNo,
OrderName,
OrderBy,
Sum(QtyIn) as QuantityIn,
Sum(QtyOut) as QuantityOut
From
tbl_Assign
Group By
OrderNo, OrderName, OrderBy
The following will create one row for every row in the tbl_Assign.
Each row will also show the summary information for the order.
This might not be what you need, but it's useful to understand it anyway.
SELECT T1.*, T2.*
FROM
( select * FROM tbl_Assign ) AS T1
LEFT JOIN ( select
OrderNo,
Sum(QtyIn) as QuantityIn,
Sum(QtyOut) as QuantityOut
from
tbl_Assign
group by
OrderNo
) AS T2
ON T1.OrderNo = T2.OrderNo
Harvey

Obtain a list with the items found the minimum amount of times in a table

I have a MySQL table where I have a certain id as a foreign key coming from another table. This id is not unique to this table so I can have many records holding the same id.
I need to find out which ids are seen the least amount of times in this table and pull up a list containing them.
For example, if I have 5 records with id=1, 3 records with id=2 and 3 records with id=3, I want to pull up only ids 2 & 3. However, the data in the table changes quite often so I don't know what that minimum value is going to be at any given moment. The task is quite trivial if I use two queries but I'm trying to do it with just one. Here's what I have:
SELECT id
FROM table
GROUP BY id
HAVING COUNT(*) = MIN(SELECT COUNT(*) FROM table GROUP BY id)
If I substitute COUNT(*) = 3, then the results come up but using the query above gives me an error that MIN is not used properly. Any tips?
I would try with:
SELECT id
FROM table
GROUP BY id
HAVING COUNT(*) = (SELECT COUNT(*) FROM table GROUP BY id ORDER BY COUNT(*) LIMIT 1);
This gets the minimum selecting the first row from the set of counts in ascendent order.
You need a double select in the having clause:
SELECT id
FROM table
GROUP BY id
HAVING COUNT(*) = (SELECT MIN(cnt) FROM (SELECT COUNT(*) as cnt FROM table GROUP BY id) t);
The MIN() aggregate function is suposed to take a column, not a query. So, I see two ways to solve this:
To properly write the subquery, or
To use temp variables
First alternative:
select id
from yourTable
group by id
having count(id) = (
select min(c) from (
select count(*) as c from yourTable group by id
) as a
)
Second alternative:
set #minCount = (
select min(c) from (
select count(*) as c from yourTable group by id
) as a
);
select id
from yourTable
group by id
having count(*) = #minCount;
You need to GROUP BY to produce a set of grouped values and additional select to get the MIN value from that group, only then you can match it against having
SELECT * FROM table GROUP BY id
HAVING COUNT(*) =
(SELECT MIN(X.CNT) AS M FROM(SELECT COUNT(*) CNT FROM table GROUP BY id) AS X)

MySQL - Fetching lowest value

My database structure contains columns: id, name, value, dealer. I want to retrieve row with lowest value for each dealer. I've been trying to mess up with MIN() and GROUP BY, still - no solution.
Solution1:
SELECT t1.* FROM your_table t1
JOIN (
SELECT MIN(value) AS min_value, dealer
FROM your_table
GROUP BY dealer
) AS t2 ON t1.dealer = t2.dealer AND t1.value = t2.min_value
Solution2 (recommended, much faster than solution1):
SELECT t1.* FROM your_table t1
LEFT JOIN your_table t2
ON t1.dealer = t2.dealer AND t1.value > t2.value
WHERE t2.value IS NULL
This problem is very famous, so there is a special page for this in Mysql's manual.
Check this: Rows Holding the Group-wise Maximum/Minimum of a Certain Column
select id,name,MIN(value) as pkvalue,dealer from TABLENAME
group by id,name,dealer;
here you group all rows by id,name,dealer and then you will get min value as pkvalue.
SELECT MIN(value),dealer FROM table_name GROUP BY dealer;
First you need to resolve the lowest value for each dealer, and then retrieve rows having that value for a particular dealer. I would do this that way:
SELECT a.*
FROM your_table AS a
JOIN (SELECT dealer,
Min(value) AS m
FROM your_table
GROUP BY dealer) AS b
ON ( a.dealer= b.dealer
AND a.value = b.m )
Try following:
SELECT dealer, MIN(value) as "Lowest value"
FROM value
GROUP BY dealer;
select id, name, value, dealer from yourtable where dealer
in(select min(dealer) from yourtable group by name, value)
These answers seem to miss the edge case of having multiple minimum values for a dealer and only wanting to return one row.
If you want to only want one value for each dealer you can use row_number partition - group - the table by dealer then order the data by value and id. we have to make the assumption that you will want the row with the smallest id.
SELECT ord_tbl.id,
ord_tbl.name,
ord_tbl.value,
ord_tbl.dealer
FROM (SELECT your_table.*,
ROW_NUMBER() over (PARTITION BY dealer ORDER BY value ASC, ID ASC)
FROM your_table
) AS ord_tbl
WHERE ord_tbl.ROW_NUMBER = 1;
Be careful though that value, id and dealer are indexed. If not this will do a full table scan and can get pretty slow...