i have a problem where we need to generate Unique codes for few million rows in a table that has several other data cases.
For ex - table has data for case A, B, C - each having million rows.
Need to generate uniques only for data in case A.
Issue is that - we have a 12 digit unique number (all integers - those will not repeat within A, but can repeat across A & B & C... say like customerIDs ), but the space for storing unique code (which can be alphanumeric) is just 10 :) .
Tried to work out a solution where we can take ascii to reduce a length. For ex - if 65 appears in the 12 digit number, we will read it as "A"....& so on..this reduces 1 digit..but there is no guarantee that 65 will appear...
Any clues will be greatly appreciated.
Related
ok, i'm not sure if i can explain this right.
Lets say i have a table with three columns (id, price, maxcombo)
maybe there's like 5 rows in this table with random numbers for price. 2. id is just incremental unique key)
maxcombo specified if that price can be in a combination of up to whatever number it is.
If x was 3, i would need to find the combination that has the maximum value of the sum 1-3 columns.
So say the table had:
1 - 100 - 1
2 - 50 - 3
3 - 10 - 3
4 - 15 - 3
5 - 20 - 2
the correct answer with be just row id 1.
since 100 alone (and can only be alone based on the maxcombo number)
is greater than say 50 + 20 + 15 or 20 + 15 or 10 + 20 etc.
Does that make sense?
I mean i could just calculate all the diff combinations and see which has the largest value, but i would imagine that would take a very long time if the table was larger than 5 rows.
Was wondering any math genius or super dev out there had some advice or creative way to figure this out in a more efficient manner.
Thanks ahead of time!
I built this solution to achieve the desired query. However, it hasn't been tested in terms of efficiency.
Following the example of colums 1-3:
SELECT max(a+b+c) FROM sample_table WHERE a < 3;
EDIT:
Looking at:
The correct answer will be just row id 1
...I considered maybe I misunderstood your question, and you want the query just obtain the rowid. So, I made this other one:
SELECT a FROM sum_combo WHERE a+b+c=(
SELECT max(a+b+c) FROM sum_combo WHERE a > 3
);
Which would for sure take too long in larger tables than just 5 rows.
I have searched and found discussions and solutions to similar problems, but not quite or as complex as I'm trying to figure out.
I have an access table which consists of two columns Draw Number and Number Drawn as shown below. Draw Number is repeated 20 times, to correspond to the 20 numbers that are drawn in each particular draw.
I'm trying to figure a way to determine the most frequent occurring combination of numbers (5 numbers) for all of the draws in each of the 20 number sets. So for instance, 12341 occurs n x, 12342 occurs nx, 12343 occurs n x, etc.
I've created parameter queries which allow me to search for different number combinations from 2 to 10 numbers, and they work OK returning the number of occurrences of a combination of numbers that I input through a simple UI. But the goal is to figure out pragmatically what the optimum combination of numbers.
Hope this makes sense. And by the way, there are 36 million or so rows in the table. The para queries work quite well however; it takes just over a second to return results for each number added. So, query two numbers = 2 second wait, three numbers = 3 second wait, etc.
I've been thinking about a loop of some type but don't know how to get started? Processing time isn't an issue; can take a day if required!
This is written in VBA and has an assortment of queries, temp tables, etc to get the job done.
The text says Access, but the tags say MySql, which is it? – RBarryYoung 21 hours ago
This part confuses me: I'm trying to figure a way to determine the most frequent occurring combination of numbers (5 numbers) for all of the draws in each of the 20 number sets. So for instance, 12341 occurs n x, 12342 occurs nx, 12343 occurs n x, etc. – Newd 21 hours ago
^What do you mean five numbers? No where in your sample data do I see 12341. Please explain using the data you have, and give expected results using that data. – McAdam331 21 hours ago
drosberg - clarification:
thanks for the response. It is an Access application, but as a first-time poster Stackoverflow recommends tags?
By five numbers I mean the most frequently occurring group of five numbers (I used five as an example, could be groups of 2 to 10 numbers) which occur in each draw, where a draw consists of 20 drawn numbers from a total of 80 numbers. So the data that I posted was intended as an example. The sample provided only has 50, 51 in common. I can plug 50 and 51 into the parameter query and it will tell me that this combination occurs 60,000 times (or whatever), but perhaps 50 and 57 occurs 65,000 times.
If i was to do this manually, and assuming I'm looking for the most frequent 5 number combination I would enter the following in the parameter query: 1,2,3,4,1 group = 30,000 occurrences 1,2,3,4,2 group = 31,000 occurrences 1,2,3,4,3 group = 31,050 occurrences 1,2,3,4,4 group = 29,050 occurrences etc........... etc...........
but I would have to do this for every combination of 5 numbers that can be derived from the numbers 1 thru 80. I'm hoping to have program do the work!!
thanks
don
DRAW NUMBER NUMBER DRAWN
1 1
1 28
1 19
1 3
1 38
1 46
1 43
1 29
1 13
1 22
1 20
1 11
1 50
1 51
1 53
1 54
1 57
1 64
1 76
1 78
2 29
2 14
2 2
2 1
2 35
2 40
2 39
2 30
2 10
2 27
2 21
2 6
2 42
2 50
2 51
2 53
2 54
2 61
2 65
2 69
I wrote a post a while ago about generating permutations with and without repetition using Excel. Perhaps you can use it.
https://michiel.wordpress.com/2015/03/29/permutations-with-repetition-using-excel/
Here's how it works. I am using strings, but you can easily modify that for numbers (since you say you need 5).
You can use the MID function to grab a single char from a string, and generate permutations from it.
=MID(Pattern,MOD([N]/[P],Length)+1,1)
N revers to the column N
P refers to the horizontal row (1,4,16). You can generate these with a formula like =4^.
After putting in the code, you can make a list of all permutations in Excel and in the cell next to it generate a sql query that you can perform as well from VBA.
Example: Looking up Access database in Excel
Or find a commercial tool like http://thingiequery.com/
I don't know if there's any open source tools for it.
I'm thinking that you should consider:
Say there are 100 balls.
Setting up a table to have one row for each "Draw number" with 100 columns one for every possible number each column has type boolean.
When you look to see which draws had number 23 you just add a
WHERE Column23 = true.
For numbers 23 and 56
WHERE Column23 = true AND Column56 = true
This should massivel simplify and speed up your SQL.
You set up a table with every possible combination of numbers.
You run SQL to find the counts.
Harvey
Let's say I have this strings in a MySQL table:
id | hash
1 | 462a276e262067573e553b5f6a2b4a323e35272d3c6b6227417c4f2654
2 | 5c2670355b6e503f39427a435a423d6d4c7c5156344c336c6c244a7234
3 | 35785c5f45373c495b70522452564b6f4531792b275e40642854772764
...
millions of records !
Now I have a set of substrings (6 character size), for example this:
["76e262", "435a42", "75e406", "95b705", "344c33"]
What I want is to know how many of these substrings are in each string, so the result could be:
id | matches
63 | 5
34 | 5
123 | 3
153 | 3
13 | 2
9 | 1
How can achieve this in a fast way ?
Real numbers and sizes are:
1) Table with 100.000/200.000 hashes
2) Main Hash size: 256 bytes
3) Substring of mini-hashes: 16 of 32 each one
NOTE: I'd like to avoid the "%LIKE%" since it's 16 likes for each row, and millions rows
You can accomplish this by using the Aho-Corasick algorithm: http://en.wikipedia.org/wiki/Aho%E2%80%93Corasick_string_matching_algorithm
MySQL doesn't have a function for that, so you'd need to write your own or consider using a language like java or c to massage the data.
How about a different approach?
You could also consider having a shifting mechanism for your data and the check on the shifting. For example, if your key is 462a276e262067573e553b5f6a2b4a323e35272d3c6b6227417c4f2654 and you know that your hash will have 58 chars, then you would have these variations:
62a276e262067573e553b5f6a2b4a323e35272d3c6b6227417c4f26544
2a276e262067573e553b5f6a2b4a323e35272d3c6b6227417c4f265446
a276e262067573e553b5f6a2b4a323e35272d3c6b6227417c4f2654462
276e262067573e553b5f6a2b4a323e35272d3c6b6227417c4f2654462a
...
Each one of these would be in a column, every one of them would be indexed.
So your query would be simply:
Select * from table where hash like "a27e262%" or s1 like "a27e262%" ...
Note that this would be MUCH faster than LIKE "%value%" as the column is indexed and the LIKE is only checking the begins with.
There are many disadvantages to this solutions: space required for the extra columns, insertion and update time would increase because of the time calculating the shifted columns, and time required to process the result of the select. But you wouldn't need to implement the algorithm in mysql.
You could also require that the minimum length of the string being searched is 6 chars, so you won't need to shift the whole string, only to keep the first 6 digits. If a match is found then you keep looking for the next 6 digits on the next match.
I am working on a ssrs report with column grouping. the followin is my scenario.
Matrix 1:
ID 2012 2013
1 20 40
1 30 50
Total 50 90
Matrix 2:
ID 2012 2013
1 60 70
1 60 80
Total 120 150
I need the sum of matrix1 and matrix2 like below:
ID 2012 2013
1 170 240
But I got the result like :
ID 2012 2013
1 410 410
I have applied column grouping in all the 3 matrices and gave the expression to get sum for matrix 3 as: =Sum(Fields!amount1.Value, "dsmatrix1") + Sum(Fields!Tamount1.Value, "dsmatrix2")
Please help me to get a solution for this.
Thanks!
I think I know what's going on. Correct me if I'm wrong.
Based on what I'm seeing, I'm guessing that Matrix 1 and Matrix 2 only have three fields each, an ID field, an amount field (being "amount1" or "Tamount1"), and a year field.
Your column grouping is manipulating the display of the data to show all values broken out by year. This works fine when looking at data from a single dataset. However, your formula is specifying that the sum of everything in the Amount1 field of dsmatrix1 and the Tamount1 field of dsmatrix2 should be added. This does not take into account the column grouping. Your expression is essentially taking all of the values from both datasets and adding them together.
Not knowing more about your query structure or how the data is filtered, my best guess is that you need another SQL dataset. In this case, you would take the queries from your two previous datasets and union them with the "Union All" command. Note that you will want to use Union All and not just Union. More on that here: What is the difference between UNION and UNION ALL?
Your end result should look something like this:
--This will be your dsmatrix1 query copied and pasted
Select ...
Union All
--This will be your dsmatrix2 query copied and pasted
Select ...
--Place one single Order by clause at the bottom
Order by ...
Note: for your two queries to be unioned properly, you'll need to make sure that each have the same number of fields, each with the same data types. Then you can point your third matrix to the new dataset.
Hope that helps!
I would like help with sql query code to push the consequent data in a specific column down by a row.
For example in a random table like the following,
x column y column
6 6
9 4
89 30
34 15
the results should be "pushed" down a row, meaning
x column y column
6 null or 0 (preferably)
9 6
89 4
34 30
SQL tables have no inherent concept of ordering. Hence, the concept of "next row" does not make sense.
Your example has no column that specifies the order for the rows. There is no definition of next. So, what you want to do cannot be done.
I am not aware of a simple way to do this with the way you are showing the table being formatted. If your perhaps added two consecutively numbered integer fields that provide row number and row number + 1 values, you could join the table to itself and get that information.
After taking a backup of you table:
Make a PHP function that will:
- Load all values of Y into an array
- Set Y = 0 (MYSQL UPDATE)
- load the values back from PHP array to MYSQL