I want to get the rownumber of each row from a MySQL Table. I already read this article and tried the suggested select statement as below,
SELECT #rownum:=#rownum + 1 as row_number,
t.*
FROM (
select * from myTable
) t,
(SELECT #rownum := 0) r
But I am getting in syntax error as below when I ran in Dbeaver,
SQL Error [1064] [42000]: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'row_number,
t.*
FROM (
select * from myTable
) t,
(SELECT #r' at line 1
Can someone please help? I am new to MySQL. I am using version 8.0. Once it's tested I would basically want to use this select in my Apache Spark Code
use this one:
SELECT #rownum:=#rownum + 1 as row_num,
t.*
FROM (
select * from myTable
) t,
(SELECT #rownum := 0) r;
row_number is a reserved keyword of mysql, you can not use it as alias or for any other purpose.
Try something like this.
SELECT *,
ROW_NUMBER() OVER(PARTITION BY 'some column' ) AS row_num
FROM my_table
(https://www.javatpoint.com/mysql-row_number-function)
Related
I tried below query to partition by but which fails with below query, the inner query works
select issueid, task_type, assignee, timeoriginalestimate, CREATED,
dense_rank() over ( partition by issueid order by CREATED desc ) as rank
from(
--- Complex query with p.pname, i.issuenum, cg.issueid, it.pname task_type, i.assignee, i.timeoriginalestimate, cg.CREATED, columns which works fine
)
Exception:
You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '( partition by issueid order by CREATED desc ) as rank
from(
SELECT p.pna' at line 3
Update:
SELECT VERSION(); -- 5.6.27
Although your MySQL version do not support Window function, I am letting this is not the issue. Guess you have a higher version and window function is supported.
Now, in your query you have defined the Alias of a column name to "Rank" which is a reserved keyword for your database and you can not use that as column name.
Hope this below hints will help you-
select
issueid,
task_type,
assignee,
timeoriginalestimate,
CREATED,
dense_rank() over ( partition by issueid order by CREATED desc ) as rn -- change the alias name
from(
-- Your subquery
) A -- Also need to give a Alias name to your sub query
Finally, if you have lower version check this LINK for help to get an idea of creating Row_number or Ranking for MySQL older versions.
In addition, this following sample query will really help you finding solution for different type row_number in mysql-
SET #simple_row_number := 0;
SET #id_wise_row_number := 0;
SET #dense_rank_per_id := 0;
SET #prev := 0;
SELECT *,
#simple_row_number := #simple_row_number + 1 AS simple_row_number,
#id_wise_row_number := IF(issueid > #prev, #id_wise_row_number + 1, #id_wise_row_number) AS id_wise_row_number,
#dense_rank_per_id :=IF(issueid > #prev,1, #dense_rank_per_id + 1) AS dense_rank_per_id,
#prev := A.issueid Prev_IssueId
FROM (
SELECT 1 issueid, '20200601' CREATED UNION ALL
SELECT 1 issueid, '20200401' CREATED UNION ALL
SELECT 1 issueid, '20200501' CREATED UNION ALL
SELECT 1 issueid, '20200201' CREATED UNION ALL
SELECT 1 issueid, '20200301' CREATED UNION ALL
SELECT 2 issueid, '20200301' CREATED UNION ALL
SELECT 2 issueid, '20200201' CREATED UNION ALL
SELECT 2 issueid, '20200401' CREATED
) A
ORDER BY issueid, CREATED DESC
This query is throwing error, it seems correct but i am getting an error
WITH Rows AS (SELECT *,
ROW_NUMBER() OVER (ORDER BY userid asc) as [Row]
FROM users
WHERE 1=1
)
SELECT * FROM Rows
WHERE Row >= 1 and Row <= 10
error i am getting while running the above statement is:
1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'Rows AS (SELECT *, ROW_NUMBER() OVER (ORDER BY userid asc)
FROM users
' at line 1
Your error is on Rows because MySQL does not recognize the CTE.
Then, MySQL also does not recognize [, so you want to use a more reasonable name. In MySQL 8+, that would be something like:
WITH Rows AS (
SELECT *,
ROW_NUMBER() OVER (ORDER BY userid asc) as seqnum
FROM users
)
SELECT *
FROM Rows
WHERE seqnum <= 10;
You don't need to compare to 1. That is definitional.
Of course, this, in turn, is overkill. The CTE is unnecessary:
SELECT *,
ROW_NUMBER() OVER (ORDER BY userid asc) as seqnum
FROM users
ORDER BY userid
LIMIT 10;
But this will still fail, because MySQL versions started recognizing CTEs and window functions in the same version.
So, you can just use variables:
SELECT u.*, (#rn := #rn + 1) as seqnum
FROM users u CROSS JOIN
(SELECT #rn := 0) params
ORDER BY userid
LIMIT 10;
This below was originally written for MySQL, with the #rownumber is defined as a scalar-variable.
SELECT CONCAT( z.expected, IF(z.got-1>z.expected, CONCAT(' thru ',z.got-1), '') AS `Missing Receipt ID`
FROM (SELECT #rownum \\:= #rownum+1 AS expected,
IF(#rownum=recpt_id, 0, #rownum \\:= recpt_id) AS got
FROM
(SELECT #rownum \\:= (SELECT MIN(CAST(recpt_id AS SIGNED))-1 FROM report_receipt
WHERE outlet_desc IN "+Branch+" )
) AS a
JOIN report_receipt r
ON r.outlet_desc IN "+Branch+"
ORDER BY CAST(recpt_id AS SIGNED)
) AS z
WHERE z.got!=0
I am trying to create the same query but for the SQL Server platform. I am aware that in MSSQL, we can use the ROW_NUMBER function and then have a OVER(ORDER ) clause at a place where the ROW_NUMBER is called. The query is also going to be used in native query format in our Java code.
So far, after some minor syntax adjustments, I have reached to this current state in MSSQL but with some uncertainties:
SELECT CONCAT( z.expected, CASE WHEN z.got-1>z.expected THEN CONCAT(' thru ',z.got-1) ELSE '' END) AS [Missing Receipt ID]
FROM
(SELECT #rownum \:= #rownum+1 AS expected,
IF(#rownum=recpt_id, 0, #rownum \:= recpt_id) AS got
FROM (SELECT ROW_NUMBER() OVER(ORDER BY CAST(recpt_id AS INT))) \:= (SELECT MIN(CAST(recpt_id AS INT))-1 FROM report_receipt
WHERE outlet_desc IN "+Branch+" )
) AS a
JOIN report_receipt r
ON r.outlet_desc IN ('MY011')) AS z
WHERE z.got!=0
What I'm unsure but looking for answers would be:
If there's is only one place ORDER clause is placed, do we just place it inside the innermost query while for other places we have to use only ROW_NUMBER() OVER(ORDER BY SELECT NULL)?
If the query is considered having unnecessary additional nesting, what is the other alternative without having to call too many ROW_NUMBER functions repeatedly?
Thanks in advance.
Note: The '\' is an escape character added for the Java code.
This question already has answers here:
ROW_NUMBER() in MySQL
(26 answers)
Closed 6 years ago.
Please let me know if there is any syntax error because, as per my understanding, the query is perfect:
mysql> SELECT Cust_Id,Plan_Id FROM(SELECT Cust_Id,Plan_Id,ROW_NUMBER() OVER (PARTITION BY Cust_Id ORDER BY cnt DESC) AS RN FROM(SELECT Cust_Id,Plan_Id,COUNT(1) as cnt FROM customer GROUP BY (Cust_Id,Plan_Id))) WHERE RN =1;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual
that corresponds to your MySQL server version for the right syntax to use
near '(PARTITION BY Cust_Id ORDER BY cnt DESC) AS RN FROM(SELECT Cust_Id,Plan_Id,COUNT'
at line 1
MYSQL does not support ROW_NUMBER().
You have to rewrite your query as below
SELECT Cust_Id,Plan_Id
FROM (
SELECT Cust_Id,Plan_Id,
#row_num := IF(#prev_value=T.Cust_Id,#row_num+1,1) AS RN,
#prev_value := T.Cust_Id
FROM (
SELECT Cust_Id,Plan_Id,COUNT(1) as cnt
FROM customer
GROUP BY (Cust_Id,Plan_Id)
) T,
(SELECT #row_num := 1) x,
(SELECT #prev_value := 0) y
)S WHERE RN =1;
I am trying to use a mysql query in my java servlet, but since '#' it is not support in hql (org.hibernate.QueryException: unexpected char: '#') I am stuck.
The query is supposed to select every nth (e.g. 10) rows in my table as follow:
SELECT ranked.COLUMN_NAME
FROM (
SELECT
#row := #row +1 AS rownum, COLUMN_NAME
FROM (
SELECT #row :=0) r, TABLENAME
) ranked
WHERE rownum % 10 = 1
Any idea will be appreciated.