Using MySQL v8.0 right now.
The question is:
Write an SQL query to report the id and the salary of the second highest salary from the
Employee table. If there is no second highest salary, the query should
report null.
My dummy data is:
Create table If Not Exists Employee (id int, salary int);
insert into Employee (id, salary) values
(1, 100);
My ideal output is like this:
+------+--------+
| id | salary |
+------+--------+
| NULL | NULL |
+------+--------+
I used DENSE_RANK as a more straightforward way for me to solve this question:
WITH sub AS (SELECT id,
salary,
DENSE_RANK() OVER (ORDER BY salary DESC) AS num
FROM Employee )
SELECT id, salary
FROM sub
WHERE num = 2
But I have a problem exporting NULL when there's no second highest salary. I tried IFNULL, but it didn't work. I guess it's because the output is not actually null but just empty.
Thank you in advance.
WITH sub AS (
SELECT id,
salary,
DENSE_RANK() OVER (ORDER BY salary DESC) AS num
FROM Employee
)
SELECT id, salary
FROM sub
WHERE num = 2
UNION ALL
SELECT NULL, NULL
WHERE 0 = ( SELECT COUNT(*)
FROM sub
WHERE num = 2 );
https://dbfiddle.uk/?rdbms=mysql_8.0&fiddle=31f5afb0e7e5dce9c2c128ccc49a6f42
Just making your query a subquery and left joining from a single-row producing subquery seems to me the simplest approach:
select id, salary
from (select null) at_least_one_row
left join (
select id, salary
from (
select id, salary, dense_rank() over (order by salary desc) as num
from Employee
) ranked_employees
where num = 2
) second_highest_salary on true
(I usually prefer a subquery to a cte that's only used once; I find that obfuscatory.)
I have mysql table like this
I want to get row that has minimum 2 or more than 2 (multiple) row only from this table, so the result would be like this
What do i do?
thank you
Use GROUP BY and HAVING clauses
SELECT t.* FROM my_table t
JOIN (
SELECT cust_id, MIN(transaction_no) AS transaction_no
FROM my_table
GROUP BY cust_id
HAVING COUNT(cust_id) > 1
) agg ON t.transaction_no = agg.transaction_no
I have a table with the following structure:
id name
1 X
1 X
1 Y
2 A
2 A
2 B
Basically what I am trying to do is to write a query that returns X for 1 because X has repeated more than Y (2 times) and returns A for 2. So if a value occurs more than the other one my query should return that. Sorry if the title is confusing but I could not find a better explanation. This is what I have tried so far:
SELECT MAX(counted) FROM(
SELECT COUNT(B) AS counted
FROM table
GROUP BY A
) AS counts;
The problem is that my query should return the actual value other than the count of it.
Thanks
This should work:
SELECT count(B) as occurrence, A, B
FROM table
GROUP BY B
ORDER BY occurrence DESC
LIMIT 1;
Please check: http://sqlfiddle.com/#!9/dfa09/3
You can try like this using a GROUP BY clause. See a Demo Here
select *, max(occurence) as Maximum_Occurence from
(
select B, count(B) as occurence
from table1
group by B
) xxx
This is how I finally handled my problem. Not the most efficient way but get the job done:
select A,B from
(select A,B, max(cnt) from
(select A ,B ,count(B) as cnt
from myTable
group by A,B
order by cnt desc
) as x group by A
) as xx
What is the simplest SQL query to find the second largest integer value in a specific column?
There are maybe duplicate values in the column.
SELECT MAX( col )
FROM table
WHERE col < ( SELECT MAX( col )
FROM table )
SELECT MAX(col)
FROM table
WHERE col NOT IN ( SELECT MAX(col)
FROM table
);
In T-Sql there are two ways:
--filter out the max
select max( col )
from [table]
where col < (
select max( col )
from [table] )
--sort top two then bottom one
select top 1 col
from (
select top 2 col
from [table]
order by col) topTwo
order by col desc
In Microsoft SQL the first way is twice as fast as the second, even if the column in question is clustered.
This is because the sort operation is relatively slow compared to the table or index scan that the max aggregation uses.
Alternatively, in Microsoft SQL 2005 and above you can use the ROW_NUMBER() function:
select col
from (
select ROW_NUMBER() over (order by col asc) as 'rowNum', col
from [table] ) withRowNum
where rowNum = 2
I see both some SQL Server specific and some MySQL specific solutions here, so you might want to clarify which database you need. Though if I had to guess I'd say SQL Server since this is trivial in MySQL.
I also see some solutions that won't work because they fail to take into account the possibility for duplicates, so be careful which ones you accept. Finally, I see a few that will work but that will make two complete scans of the table. You want to make sure the 2nd scan is only looking at 2 values.
SQL Server (pre-2012):
SELECT MIN([column]) AS [column]
FROM (
SELECT TOP 2 [column]
FROM [Table]
GROUP BY [column]
ORDER BY [column] DESC
) a
MySQL:
SELECT `column`
FROM `table`
GROUP BY `column`
ORDER BY `column` DESC
LIMIT 1,1
Update:
SQL Server 2012 now supports a much cleaner (and standard) OFFSET/FETCH syntax:
SELECT [column]
FROM [Table]
GROUP BY [column]
ORDER BY [column] DESC
OFFSET 1 ROWS
FETCH NEXT 1 ROWS ONLY;
I suppose you can do something like:
SELECT *
FROM Table
ORDER BY NumericalColumn DESC
LIMIT 1 OFFSET 1
or
SELECT *
FROM Table ORDER BY NumericalColumn DESC
LIMIT (1, 1)
depending on your database server. Hint: SQL Server doesn't do LIMIT.
The easiest would be to get the second value from this result set in the application:
SELECT DISTINCT value
FROM Table
ORDER BY value DESC
LIMIT 2
But if you must select the second value using SQL, how about:
SELECT MIN(value)
FROM ( SELECT DISTINCT value
FROM Table
ORDER BY value DESC
LIMIT 2
) AS t
you can find the second largest value of column by using the following query
SELECT *
FROM TableName a
WHERE
2 = (SELECT count(DISTINCT(b.ColumnName))
FROM TableName b WHERE
a.ColumnName <= b.ColumnName);
you can find more details on the following link
http://www.abhishekbpatel.com/2012/12/how-to-get-nth-maximum-and-minimun.html
MSSQL
SELECT *
FROM [Users]
order by UserId desc OFFSET 1 ROW
FETCH NEXT 1 ROW ONLY;
MySQL
SELECT *
FROM Users
order by UserId desc LIMIT 1 OFFSET 1
No need of sub queries ... just skip one row and select second rows after order by descending
A very simple query to find the second largest value
SELECT `Column`
FROM `Table`
ORDER BY `Column` DESC
LIMIT 1,1;
SELECT MAX(Salary)
FROM Employee
WHERE Salary NOT IN ( SELECT MAX(Salary)
FROM Employee
)
This query will return the maximum salary, from the result - which not contains maximum salary from overall table.
Old question I know, but this gave me a better exec plan:
SELECT TOP 1 LEAD(MAX (column)) OVER (ORDER BY column desc)
FROM TABLE
GROUP BY column
This is very simple code, you can try this :-
ex :
Table name = test
salary
1000
1500
1450
7500
MSSQL Code to get 2nd largest value
select salary from test order by salary desc offset 1 rows fetch next 1 rows only;
here 'offset 1 rows' means 2nd row of table and 'fetch next 1 rows only' is for show only that 1 row. if you dont use 'fetch next 1 rows only' then it shows all the rows from the second row.
Simplest of all
select sal
from salary
order by sal desc
limit 1 offset 1
select * from (select ROW_NUMBER() over (Order by Col_x desc) as Row, Col_1
from table_1)as table_new tn inner join table_1 t1
on tn.col_1 = t1.col_1
where row = 2
Hope this help to get the value for any row.....
Use this query.
SELECT MAX( colname )
FROM Tablename
where colname < (
SELECT MAX( colname )
FROM Tablename)
select min(sal) from emp where sal in
(select TOP 2 (sal) from emp order by sal desc)
Note
sal is col name
emp is table name
select col_name
from (
select dense_rank() over (order by col_name desc) as 'rank', col_name
from table_name ) withrank
where rank = 2
SELECT
*
FROM
table
WHERE
column < (SELECT max(columnq) FROM table)
ORDER BY
column DESC LIMIT 1
It is the most esiest way:
SELECT
Column name
FROM
Table name
ORDER BY
Column name DESC
LIMIT 1,1
As you mentioned duplicate values . In such case you may use DISTINCT and GROUP BY to find out second highest value
Here is a table
salary
:
GROUP BY
SELECT amount FROM salary
GROUP by amount
ORDER BY amount DESC
LIMIT 1 , 1
DISTINCT
SELECT DISTINCT amount
FROM salary
ORDER BY amount DESC
LIMIT 1 , 1
First portion of LIMIT = starting index
Second portion of LIMIT = how many value
Tom, believe this will fail when there is more than one value returned in select max([COLUMN_NAME]) from [TABLE_NAME] section. i.e. where there are more than 2 values in the data set.
Slight modification to your query will work -
select max([COLUMN_NAME])
from [TABLE_NAME]
where [COLUMN_NAME] IN ( select max([COLUMN_NAME])
from [TABLE_NAME]
)
select max(COL_NAME)
from TABLE_NAME
where COL_NAME in ( select COL_NAME
from TABLE_NAME
where COL_NAME < ( select max(COL_NAME)
from TABLE_NAME
)
);
subquery returns all values other than the largest.
select the max value from the returned list.
This is an another way to find the second largest value of a column.Consider the table 'Student' and column 'Age'.Then the query is,
select top 1 Age
from Student
where Age in ( select distinct top 2 Age
from Student order by Age desc
) order by Age asc
select age
from student
group by id having age< ( select max(age)
from student
)
order by age
limit 1
SELECT MAX(sal)
FROM emp
WHERE sal NOT IN ( SELECT top 3 sal
FROM emp order by sal desc
)
this will return the third highest sal of emp table
select max(column_name)
from table_name
where column_name not in ( select max(column_name)
from table_name
);
not in is a condition that exclude the highest value of column_name.
Reference : programmer interview
Something like this? I haven't tested it, though:
select top 1 x
from (
select top 2 distinct x
from y
order by x desc
) z
order by x
See How to select the nth row in a SQL database table?.
Sybase SQL Anywhere supports:
SELECT TOP 1 START AT 2 value from table ORDER BY value
Using a correlated query:
Select * from x x1 where 1 = (select count(*) from x where x1.a < a)
select * from emp e where 3>=(select count(distinct salary)
from emp where s.salary<=salary)
This query selects the maximum three salaries. If two emp get the same salary this does not affect the query.
I have a table having id and no field, what I really want is the result raw will be repeated no filed times, if the no field is 2 then that raw must be repeated twice in result.
this is my sample table structure:
id no
1 3
2 2
3 1
now I need to get a result like:
1 3
1 3
1 3
2 2
2 2
3 1
I tried to write mysql query to get the result like above, but failed.
You need a table of numbers to accomplish this. For just three values, this is easy:
select t.id, t.no
from t join
(select 1 as n union all select 2 union all select 3
) n
on t.no <= n.no;
This query must do what you want to achieve:
select t.id, t.no from test t cross join test y where t.id>=y.id
not completely solve your problem, but this one can help
set #i=0;
select
test_table.*
from
test_table
join
(select
#i:=#i+1 as i
from
any_table_with_number_of_rows_greater_than_max_no_of_test_table
where
#i < (select max(no) from test_table)) tmp on no >= i
order by
id desc
EDIT :
This is on SQL Server. I checked online and see that CTEs work on MySQL too. Just couldn't get them to work on SQLFiddle
Try this, remove unwanted columns
create table #temp (id int, no int)
insert into #temp values (1, 2),(2, 3),(3, 5)
select * from #temp
;with cte as
(
select id, no, no-1 nom from #temp
union all
select c.id, c.no, c.nom-1 from cte c inner join #temp t on t.id = c.id and c.nom < t.no and c.nom > 0
)
select * from cte order by 1
drop table #temp