Please help me.
Here is the raw data:
uid | id | value |
1 | a | 389 |
2 | b | 201 |
3 | c | 170 |
if.... When the reference value is '200'
How do you get it to come out like this?
mysql..
no| uid | id | value | cut
1 | 1 | a | 200 | 200
2 | 1 | a | 189 | 200
3 | 2 | b | 200 | 200
4 | 2 | b | 1 | 200
5 | 3 | c | 170 | 200
help me!!!!
If you are using MySQL 8 or later, Recursive CTEs can help:
CREATE DATABASE test;
USE test;
CREATE TABLE TestData (uid INTEGER, id VARCHAR(8), value INTEGER);
INSERT INTO TestData VALUES (1, 'a', 389);
INSERT INTO TestData VALUES (2, 'b', 201);
INSERT INTO TestData VALUES (3, 'c', 170);
INSERT INTO TestData VALUES (4, 'd', 550);
-- Set up an auto-incrementing row number
SET #row_num = 0;
WITH RECURSIVE cte (uid, id, value, remainder) AS (
-- start with a copy of the table, but adding another column for the value that is at most 200
SELECT a.uid, a.id, LEAST(a.value, 200), a.value AS "remainder" FROM TestData a
UNION
-- repeatedly select from the previous result set, meanwhile decrementing the "remainder" column
SELECT uid, id, LEAST(remainder - 200, 200), remainder - 200 FROM cte WHERE remainder > 200
)
-- select the actual data that we care about
SELECT (#row_num := #row_num + 1) AS no, uid, id, value, 200 AS "cut" FROM cte ORDER BY id, value DESC;
This results in the following table:
no | uid | id | value | cut
1 | 1 | a | 200 | 200
2 | 1 | a | 189 | 200
3 | 2 | b | 200 | 200
4 | 2 | b | 1 | 200
5 | 3 | c | 170 | 200
6 | 4 | d | 200 | 200
7 | 4 | d | 200 | 200
8 | 4 | d | 150 | 200
How about this:
SET #row_num = 0;
SELECT (#row_num := #row_num + 1) AS "no",uid,id,valueA, "200" as cut FROM
(SELECT uid,id,IF(valueA/200 > 1,200,valueA) AS "valueA" FROM tableA UNION ALL
SELECT uid,id,IF(valueA/200 > 2,200,valueA-200) AS "valueA" FROM tableA UNION ALL
SELECT uid,id,IF(valueA/200 > 3,200,valueA-400) AS "valueA" FROM tableA) a
WHERE valueA > 0
ORDER BY uid,id,valueA DESC;
If valueA divide by 200 equal to more than 1, it will return 200, otherwise it will only return what's in valueA. That's the first syntax among the UNION ALL queries.
The second one I added another condition to as if valueA divided by 200 IS NOT equal to more than 2, it will return valueA-200. You can try to execute the UNION ALL queries to see the results.
It's not the best way to do it and I am sure that there are better solution out there but I got it working using this method. You might use this as temporary solution or at least give you some ideas.
Consider writing a stored procedure instead of doing this all in pure SQL or just select the rows from the table and do the following in php:
From my understanding, you're looking for this:
no = 1
For each row in the result set
for i = 0 to int(value/cut)
output the row with value set to cut
no += 1
output the row with value set to mod(value, cut)
no += 1
Related
Is there a way to make two or more same values in the same column to be different by database engine?
Imagine that I have column like this:
id | votes
----------
1 | 20
2 | 20
3 | 19
4 | 16
5 | 15
I have to make all the votes different in that way that i increment first of two equal values, and substract other one.
After one iteration my DB should look like this:
----------
1 | 21
2 | 19
3 | 19
4 | 16
5 | 15
Because we still have two same values (id 2 and 3) we keep going with second iteration:
----------
1 | 21
2 | 20
3 | 18
4 | 16
5 | 15
Can i update mysql database somehow to make that for me? Or should i select values, compare them in php and update?
Thank you!
This does not exactly match your expected result, but may lead you toward an acceptable compromise.
MySQL does not yet have window functions such as rank(), dense_rank() or row_number() but you can mimic row_number using #variables such as seen below.
See this demo
MySQL 5.6 Schema Setup:
CREATE TABLE Table1
(`id` int, `votes` int)
;
INSERT INTO Table1
(`id`, `votes`)
VALUES
(1, 20),
(2, 20),
(3, 19),
(4, 16),
(5, 15)
;
Query 1:
SELECT
t.id
, t.votes
, m.v - #row_num AS adjusted_votes
, #row_num := #row_num+1 AS RowNumber
FROM Table1 t
CROSS JOIN (SELECT MAX(votes) v from Table1) m
CROSS JOIN (SELECT #row_num :=0) vars
ORDER BY
t.votes DESC
, t.id
Results:
| id | votes | adjusted_votes | RowNumber |
|----|-------|----------------|-----------|
| 1 | 20 | 20 | 1 |
| 2 | 20 | 19 | 2 |
| 3 | 19 | 18 | 3 |
| 4 | 16 | 17 | 4 |
| 5 | 15 | 16 | 5 |
Note that the reduction of 20 to 19 for id 2 appears to be completely arbitrary and that id is used purely as a tie-breaker when values are equal.
I have a very simple table filled with about 500k records
| ID_1 | ID_2 | Date | Fields... |
+-------+-------+-------------+-----------+
| 1 | 1 | 1/1/2016 | abc |
| 2 | 1 | 2/1/2016 | abc |
| 3 | 2 | 1/2/2016 | abc |
| 4 | 3 | 1/2/2016 | abc |
| 5 | 4 | 1/2/2016 | abc |
I have to extract from that 36 values based on common parameters and differentiated by the date.
To reduce accesses to the database and increase performance I do a subquery, and then sum the results differentiating them with an if.
The not distinct sums work perfectly fine, but I need to count some distinct value and this returns me the correct value + 1.
SELECT
SUM( IF(MONTH(Date) = 1, 1, 0) ) AS A1,
SUM( IF(MONTH(Date) = 2, 1, 0) ) AS A2,
SUM( IF(MONTH(Date) = 3, 1, 0) ) AS A3,
...
COUNT(DISTINCT( IF(MONTH(Date) = '1', COALESCE(ID_cliente), 0) )) AS C1
FROM (
SELECT ID_1, ID_2, Date FROM table WHERE Fields = conditions
) AS Sub
The C1 returns 1 if the real value is 0, 2 if the real value is 1 etc
There's a solution or I must split it into two queries?
Table Mytable1
Id | Actual
1 ! 10020
2 | 12203
3 | 12312
4 | 12453
5 | 13211
6 | 12838
7 | 10l29
Using the following syntax:
SELECT AVG(Actual), CEIL((#rank:=#rank+1)/3) AS rank FROM mytable1 Group BY rank;
Produces the following type of result:
| AVG(Actual) | rank |
+-------------+------+
| 12835.5455 | 1 |
| 12523.1818 | 2 |
| 12343.3636 | 3 |
I would like to take AVG(Actual) column and UPDATE a second existing table Mytable2
Id | Predict |
1 | 11133
2 | 12312
3 | 13221
I would like to get the following where the Actual value matches the ID as RANK
Id | Predict | Actual
1 | 11133 | 12835.5455
2 | 12312 | 12523.1818
3 | 13221 | 12343.3636
IMPORTANT REQUIREMENT
I need to set an offset much like the following syntax:
SELECT #rank := #rank + 1 AS Id , Mytable2.Actual FROM Mytable LIMIT 3 OFFSET 4);
PLEASE NOTE THE AVERAGE NUMBER ARE MADE UP IN EXAMPLES
you can join your existing query in the UPDATE statement
UPDATE Table2 T2
JOIN (
SELECT AVG(Actual) as AverageValue,
CEIL((#rank:=#rank+1)/3) AS rank
FROM Table1, (select #rank:=0) t
Group BY rank )T1
on T2.id = T1.rank
SET Actual = T1.AverageValue
I have a table (innoDB) that has 3 columns: ID, ID_FATHER, ROWPOS. ID is auto_increment and ROWPOS has values from other table. I need ID_FATHER to be incremented by 1 if ROWPOS is not a sequence, if it is a sequence ID_FATHER should not increment.
Like this:
ID | ID_FATHER | ROWPOS
1 | 1 | 250
2 | 2 | 253
3 | 2 | 254
4 | 3 | 260
5 | 4 | 263
6 | 5 | 268
7 | 6 | 270
8 | 6 | 271
9 | 6 | 272
10 | 7 | 276
Is there a way to do that?
With this query:
INSERT INTO mytable (i, rowpos)
SELECT #i := IF(t.rowpos = #prev_rowpos + 1, #i, #i + 1) AS i
, #prev_rowpos := t.rowpos AS rowpos
FROM temp
JOIN (SELECT #prev_rowpos := NULL, #i := 0) v
ORDER BY t.rowpos
I am able to import into the tables I want. But the problem is in the TABLE.Service, as you can see with this solution the ID_FATHER is wrong because it only increments by 1
but in this case it actually should be 2 because invoice 1 doesn't have service.
How can I solve this problem without changing all my schema.
TABLE.temp
ROW|TYPE |INVOICE_temp
1 |xxx |10
2 |xxP |led tv
3 |xxP |mp3 Player
4 |xxx |11
5 |xxP |tv cable
6 |xxS |install
xxx = Invoice number
xxP = Product
xxs = service
TABLE.Invoice_Number TABLE.Product
ID|ID_FATHER|ROWPOS|NUM ID|ID_FATHER|ROWPOS|PROD
1 | 1 | 1 | 10 1 | 1 | 2 | led tv
2 | 2 | 4 | 11 2 | 1 | 3 | mp3 player
3 | 2 | 5 | tv cable
TABLE.Service
ID|ID_FATHER|ROWPOS|SERV
1 | 1 | 6 | install
I made some changes in the query to work as I needed.
You could do something like this:
INSERT INTO mytable (i, rowpos)
SELECT #i := IF(t.rowpos = #prev_rowpos + 1, #i, #i + 1) AS i
, #prev_rowpos := t.rowpos AS rowpos
FROM another_table t
JOIN (SELECT #prev_rowpos := NULL, #i := 0) v
ORDER BY t.rowpos
(Test just the SELECT query, get that working returning the resultset you want, before you preface it with the INSERT.)
For completeness, I will add that this technique is dependent on UNDOCUMENTED and non-guaranteed behavior in MysQL, using "user variables". I've successfully used this approach many times, but for "one off" type admin functions, not ever embedded as SQL in an application.
Note that the ORDER of the expressions in the SELECT list is important, they are evaluated in the order they appear in the SELECT list. (MySQL doesn't guarantee this behavior, but we do observe it. It's important that the check of the user variables containing values from the previous row to precede the assignment of the current row values to the user variables. That's why i is returned first, followed by rowpos. If you reversed the order of those in the SELECT list, the query would operate differently, and we wouldn't get the same results.
The purpose of the inline view (aliased as v) is to initialize the user variables. Since MySQL materializes that view query into a "derived table" before the outer query runs, those variables get initialized before they are referenced in the outer query. We don't really care what the inline view query actually returns, except that we need it to return exactly one row (because we reference it in a JOIN operation to the table we really want to query).
E.g.:
DROP TABLE IF EXISTS my_table;
CREATE TABLE my_table
(id INT NOT NULL AUTO_INCREMENT PRIMARY KEY
,rowpos INT NOT NULL
);
INSERT INTO my_table (rowpos) VALUES
(250),
(253),
(254),
(260),
(263),
(268),
(270),
(271),
(272),
(276);
SELECT x.*
, #i:=#i+ISNULL(y.id) i
FROM my_table x
LEFT
JOIN my_table y
ON y.id < x.id
AND y.rowpos = x.rowpos - 1
, (SELECT #i:=0) vals
ORDER
BY x.id;
+----+--------+------+
| id | rowpos | i |
+----+--------+------+
| 1 | 250 | 1 |
| 2 | 253 | 2 |
| 3 | 254 | 2 |
| 4 | 260 | 3 |
| 5 | 263 | 4 |
| 6 | 268 | 5 |
| 7 | 270 | 6 |
| 8 | 271 | 6 |
| 9 | 272 | 6 |
| 10 | 276 | 7 |
+----+--------+------+
Let's say I have a mySQL table whose structure is like this:
mysql> select * from things_with_stuff;
+----+---------+----------+
| id | counter | quantity |
+----+---------+----------+
| 1 | 101 | 1 |
| 2 | 102 | 2 |
| 3 | 103 | 3 |
+----+---------+----------+
My goal is to "expand" the table so I end up with something like:
mysql> select * from stuff;
+----+---------+
| id | counter |
+----+---------+
| 1 | 101 |
| 2 | 102 |
| 3 | 102 |
| 4 | 103 |
| 5 | 103 |
| 6 | 103 |
+----+---------+
And I want to do this "expansion" using only mysql. Note that I end up with a row per quantity and per counter. Any suggestions? A stored procedure is not an option here (I know they offer while loops).
Thanks!
The following will do the trick as long as some_large_table has a length greater than or equal to the largest quantity in things_with_stuff. For example, let some_large_table be a big fact table in a data warehouse.
SELECT #kn:=#kn+1 AS id, counter
FROM (SELECT #kn:=0) k, things_with_stuff ts
INNER JOIN (
SELECT #rn:=#rn+1 AS num
FROM (SELECT #rn:=0) t, some_large_table
) nums ON num <= ts.quantity;
Assuming there is a maximum value for quantity, you could do:
INSERT INTO things SELECT counter FROM things_with_stuff WHERE quantity > 0;
INSERT INTO things SELECT counter FROM things_with_stuff WHERE quantity > 1;
INSERT INTO things SELECT counter FROM things_with_stuff WHERE quantity > 2;
--... and so on until the max.
It's a bit of a hack but it should do the job.
If the ordering is important you could do a clean up afterwards.
I have sometimes in databases a table named num (number) with a single column i, filled with all integers from 1 to 1000000. It's not hard to make such a table and populate it.
Then you could use this if stuff.id is auto incremented:
INSERT INTO stuff
( counter )
SELECT ts.counter
FROM things_with_stuff AS ts
JOIN num
ON num.i <= ts.quantity