Is there a way to use my own number in a table like an auto-number; that is to automatically assign the next available to a new record. We have system ID numbers for each employee that I want to tie into this database. I just want the table to auto assign the next number.
Can I do this?
Could this be done with a mixture of numeric and alpha?
Could criteria be used, like Code A = certain set of numbers, Code B = another?
Of course you can, but you will have to design this yourself.
There are hundreds of ways of doing this but one way might be that you may have a parameters table with "nextQuote", "nextEmployeeNo", "nextJob"... of course your table design could have anything, including prefix example;
PARAMETERS
Prefix Number
Q 1145
E 54
J 999
So now you can SELECT PreFix + MAX(Number) AS NextEmployee FROM Parameters WHERE Prefix = E
And in your code you can increment the number after dealing with it.
UPDATE Parameters SET Number = number + 1 WHERE Prefix = E
If this isn't up to the job then hopefully it will get you thinking in how you can do something similar.
Hope this helps.
For ADO users:
How To Implement Multiuser Custom Counters in Jet 4.0
For DAO users:
How To Implement Multi-user Custom Counters in DAO 3.5
Related
I'm trying to find unaccounted for numbers within a substantially large SQL dataset and facing some difficulty sorting.
By default the data for column reads
'Brochure1: Brochure2: Brochure3:...Brochure(k-1): Brochure(k):'
where k stands in for the number of brochures a unique id is eligible for.
Now the issue arises as the brochures are accounted for a sample updated data would read
'Brochure1: 00001 Brochure2: 00002 Brochure3: 00003....'
How does one query out the missing numbers, if in the range of number of say 00001-88888 some haven't been accounted next to Brochure(X):
The right way:
You should change the structure of your database. If you care about performance, you should follow the good practices of relational databases, so as first comment under your question said: normalize. Instead of placing information about brochures in one column of the table, it's much faster and more clear solution to create another table, that will describe relations between brochures and your-first-table-name
<your-first-table-name>_id | brochure_id
----------------------------+---------------
1 | 00002
1 | 00038
1 | 00281
2 | 28192
2 | 00293
... | ...
Not mention, if possible - you should treat brochure_id as integer, so using 12 instead of 0012.
The difference here is, that now you can make efficient and simple queries, to find out how many brochures one ID from your first table has, or what ID any brochure belongs to. If for some reason you need to keep the ordinal number of every single brochure you can add a column to the above table, like brochure_number.
What you want to achieve (not recommended): I think the fastest way to achieve your objective without changing the db structure, is to get the value of your brochures column, and then process it with your script. You really don't want to create a SQL statement to parse this kind of data. In PHP that wolud look something like this:
// Let's assume you already have your `brochures` column value in variable $brochures
$bs = str_replace(": ", ":", $brochures);
$bs = explode(" ", $bs);
$brochures = array();
foreach($bs as $b)
$brochures[substr($b, 8, 1)] = substr($b, strpos($b, ":")+1, 5);
// Now you have $brochures array with keys representing the brochure number,
// and values representing the ID of brochure.
if(isset($brochures['3'])){
// that row has a defined Brochure3
}else{
// ...
}
Given the following 3 queries
Query 1
SELECT
COMPONENTINFO__SOFTWARE.SOFTWARENAME,
COMPONENTINFO__SOFTWARE.SOFTWAREVERSION,
COMPONENTINFO__SOFTWARE.PARENTOID,
COMPONENTINFO__SOFTWARE.OID,
COMPONENT_VERSION_INFO.OID,
COMPONENT_VERSION_INFO.HWSERIAL,
COMPONENT_VERSION_INFO.COMPONENTID
FROM
COMPONENTINFO__SOFTWARE,
COMPONENT_VERSION_INFO
WHERE
( COMPONENTINFO__SOFTWARE.PARENTOID=COMPONENT_VERSION_INFO.OID )
Query 2
SELECT
V_MACH.OID,
V_MACH.NAME,
V_MACH.IPADDR
FROM
V_MACH
Query 3
SELECT
V_VERSIONINFO.MACHINEOID,
VM_VERSIONINFO_VERSIONINFOINFO.HWSERIAL,
VM_VERSIONINFO_VERSIONINFOINFO.OSVERSION,
VM_VERSIONINFO_VERSIONINFOINFO.PARENTOID,
VM_VERSIONINFO_VERSIONINFOINFO.OID,
COMPONENT_VERSION_INFO.PARENTOID,
V_VERSIONINFO.OID
FROM
V_VERSIONINFO,
VM_VERSIONINFO_VERSIONINFOINFO,
COMPONENT_VERSION_INFO
WHERE
( VM_VERSIONINFO_VERSIONINFOINFO.PARENTOID=V_VERSIONINFO.OID )
I'm trying to produce a report (Webi, using the rich client) that shows in 1 table:
V_MACH.NAME, COMPONENTINFO__SOFTWARE.SOFTWARENAME, COMPONENTINFO__SOFTWARE.SOFTWAREVERSION
But no matter what dimensions I merge, it won't let me put the NAME field alongside the software version fields.
I've tried to merge on:
VM_VERSIONINFO_VERSIONINFOINFO.HWSERIAL + COMPONENT_VERSION_INFO.HWSERIAL.
VM_VERSIONINFO_VERSIONINFOINFO.OID + COMPONENT_VERSION_INFO.OID (I found these represent the same values for each machine)
But nothing works.
Is the only way to do a join at the SQL level? I was hoping to avoid that but if it's the only way then that's ok.
I think what you need to do is this:
1) Create a merged dimension between V_MACH.OID in Query 2 and
V_VERSIONINFO.MACHINEOID in Query 3. Call the merged dim
"machineoid".
Create a merged dimension between
VM_VERSIONINFO_VERSIONINFOINFO.OID in Query 3 and
COMPONENT_VERSION_INFO.OID in Query 1. Call the merged dim "oid".
Create a new variable as a detail type, defined as
=[V_MACH.NAME], and its associated dimension as the merged
machineoid dimension. Call it name_detail.
Use the two merged dims in place of the
underlying dims in your report block, then add in the name_detail variable.
The reason you're having trouble is that BO can't recognize what Query 2.NAME should be associated with. By creating a detail variable, you are explicitly telling it that it is an attribute of the now-merged OID dimension.
Background
I'm faced with the following problem, relating to three tables
class_sectors table contains three categories of classes
classes table contains a list of classes students can attend
class_choices contains the first, second and third class choice of the student, for each sector. So for sector 1 Student_A has class_1 as first choihce, class_3 as second choice and class_10 as third choice for example, then for sector 2 he has another three choices, etc...
The class_choices table has these columns:
kp_choice_id | kf_personID | kf_sectorID | kf_classID | preference | assigned
I think the column names are self explanatory. preference is either 1, 2 or 3. And assigned is a boolean set to 1 once we have reviewed a student's choices and assigned them to a class.
Problem:
Writing an sql query that tells the students what class they are assigned to for each sector. If their class hasn't been assigned, it should default to show their first preference.
I have actually got this to work, but using two (very bloated??) sql queries as follows:
$choices = $db -> Q("SELECT
*, concat_ws(':', `kf_personID`, `kf_sectorID`) AS `concatids`
FROM
`class_choices`
WHERE
(`assigned` = '1')
GROUP BY
`concatids`
ORDER BY
`kf_personIDID` ASC,
`kf_sectorID` ASC;");
$choices2 = $db -> Q("SELECT
*, concat_ws(':', `kf_personID`, `kf_sectorID`) AS `concatids`
FROM
`class_choices`
WHERE
`preference` = '1'
GROUP BY
`concatids`
HAVING
`concatids` NOT IN (".iimplode($choices).")
ORDER BY
`kf_personID` ASC,
`kf_sectorID` ASC;");
if(is_array($choices2)){
$choices = array_merge($choices,$choices2);
}
Now $choices does have what I want.
But I'm sure there is a way to simplify this, merge the two SQL queries, and so it's a bit more lightweight.
Is there some kind of conditional SQL query that can do this???
Your solution uses two steps to enable you to filter the data as needed. Since you are generating a report, this is a pretty good approach even if it looks a bit more verbose than you might like.
The advantage of this approach is that it is much easier to debug and maintain, a big plus.
To improve the situation, you need to consider the data structure itself. When I look at the class_choices table, I see the following fields: kf_classID, preference, assigned which contain the key information.
For each class, the assigned field is either 0 (default) or 1 (when the class preference is assigned for the student). By default, the class with preference = 1 is the assigned one since you display it in the report when assigned=0 for all the student's class choices in a particular sector.
The data model could be improved by imposing a business rule as follows:
For preference=1 set the default value assigned=1. When the class selection process
takes place, and if the student gets assigned the 2nd or 3rd choice, then preference 1 is unassigned and the alternate choice assigned.
This means a bit more code in the application but it makes the reporting a bit easier.
The source of the difficulty is that the assignment process does not explicitly assign the 1st preference. It only updates assigned if the student cannot get the 1st choice.
In summary, your SQL is good and the improvements come from taking another look at the data model.
Hope this helps, and good luck with the work!
I have a couple systems which contain a users' table along with some form of karma/weight/reputation. Sometimes it's the number of posts a user has made, sometimes it's the number of up/down votes a user has received across all their activity on the site.
USER {
id int
name string
karma int
}
How do I use these numbers to calculate that user's "weight" or "authority"? For example, the vote of one long-time member is often worth much more than 4 votes from brand new users.
I was thinking about adding up the total points/karma/reputation of all members and then trying to come up with a 1-100 scale.
SUM(user.points) / COUNT(user.*) = average user points
Then something like
CEIL(userA.points / average user points) = their weight on an issue
However, there also needs to be a curve on the points this way as I don't want someone with 5,000 posts/karma to out weigh 20 new users votes.
Mathematically, your best bet is to weight by the log of the percentile ranking of user in question. However, that is painful in SQL.
Simpler would be to cheat and assume the mean is the same as the median (a very bad assumption statistically, but much simpler programmatically):
SELECT 1 - log10(SELECT COUNT (*) FROM user
WHERE (SUM(user.points) / COUNT(user.*)) < user.points)
/ SELECT (COUNT (*) from user))
In this way, your top 10% of karma would have one and a half the impact of your average user, almost twice the impact of a noob.
Changing the log base would scale this, obviously, where natural log (log() in mysql) would give the upper 10% 3 times as much impact as a noob, and twice the impact as average. Log2() is even more extreme. (Note: subtraction is required because the log will be negative.)
If you want a more severe effect you might try squaring the log. (Note: squaring makes the log squared positive, so addition is appropriate here.)
If you want a hyperprecise rule, you can go into standard deviations, but the sql gets cumbersome and slow. It all depends on how far down the rabbit hole you want to go....
There are probably some resources that can provide you with parameters for this, but you should probably decide exactly what you want rather than using some predefined model. I suggest you define some rules for which sets of users should be equivalent or which should outweigh each other (e.g. 10 0 karma users = 1 5k karma user) (equivalence is much easier to work with), which will very quickly produce parameters for some chosen equation.
Using log (as already suggested), some (fractional) power (like square root) or even just linear can work.
I suggest something like newKarma = a.karma^b + c, and it shouldn't be to difficult to solve a, b and c. I suggest you pick b rather than trying to calculate it. Using new users (with karma = 0) should make this quite easy to solve. Guessing values to get close to what you want can be easier than determining them mathematically (since some rules together won't fit any simple equation).
Note that c above is an offset to karma, which will give many new users more total karma than high-karma users. You may also want to think about a.(karma + c)^b, or a.(karma + c)^b + d. Analysing the rules you defined should tell you which one to use.
UPDATE: Added alternatives for c
EDIT: You have some options for SQL. A temp table (with sums) might actually be the fastest. You can also just use a view. A join on the same table might also be possible, though I'm not sure. Using a view would look something like: (for some chosen a,b,c and d) (you may also want to add indices to the view)
Votes(issueID, userID) // table structure
User(userID, karma, ...) // table structure
CREATE VIEW Sums AS
SELECT issueID, SUM(1*POWER(karma + 2, 3) + 4) AS sumVal
FROM Votes JOIN User ON User.userID = Votes.userID
GROUP BY issueID
Query:
SELECT (1*POWER(karma + 2, 3) + 4)/sumVal AS influenceOnIssue
FROM Votes JOIN User ON User.userID = Votes.userID
JOIN Sums on Sums.issueID = Votes.issueID
WHERE Votes.userID = #UserID AND Votes.issueID = #IssueID
A simplification may be to have a computed column that = 1*POWER(karma + 2, 3) + 4
The faster option would be to calculate the derived karma on insert/update, either by having an additional column and using triggers or just calculating in before you call insert/update, and calling insert/update with the new value.
We want to set up a directory of all the organizations working with us. They are incredibly diverse (government, embassy, private companies, and organizations depending on them ). So, I've resolved to create 2 tables. Table 1 will treat all the organizations equally, i.e. it'll collect all the basic information (name, address, phone number, etc.). Table 2 will establish the hierarchy among all the organizations. For instance, Program for illiterate adults depends on the National Institute for Social Security which depends on the Labor Ministry.
In the Hierarchy table, each column represents a level. So, for the example above, (i)Labor Ministry - Level1(column1), (ii)National Institute for Social Security - Level2(column2), (iii)Program for illiterate adults - Level3(column3).
To attach an organization to an hierarchy, the user needs to go level by level(i.e. column by column). So, there will be at least 3 situations:
If an adequate hierarchy exists for an organization(for instance, level1: US Embassy), that organization can be added (For instance, level2: USAID).--> US Embassy/USAID, and so on.
How about if one or more levels are missing? - then they need to be added
How about if the hierarchy need to be modified? -- not every thing need to be modified.
I do not have any choice but working by level (i.e. column by column). I does not make sense to have all the levels in one form as the user need to navigate hierarchies to find the right one to attach an organization.
Let's say, I have those queries in my repository (just that you get the idea).
Query1
var orgHierarchy = (from orgH in db.Hierarchy
select orgH.Level1).FirstOrDefault;
Query2
var orgHierarchy = (from orgH in db.Hierarchy
select orgH.Level2).FirstOrDefault;
Query3, Query4, etc.
The above queries are the same except for the property queried (level1, level2, level3, etc.)
Question: Is there a general way of writing the above queries in one? So that the user can track an hierarchy level by level to attach an organization.
In other words, not knowing in advance which column to query, I still need to be able to do so depending on some conditions. For instance, an organization X depends on Y. Knowing that Y is somewhere on the 3rd level, I'll go to the 4th level, linking X to Y.
I need to select (not manually) a column with only one query that takes parameters.
=======================
EDIT
As I just said to #Mark Byers, all I want is just to be able to query a column not knowing in advance which one. Check this out:
How about this
Public Hierarchy GetHierarchy(string name)
{
var myHierarchy = from hierarc in db.Hierarchy
where (hierarc.Level1 == name)
select hierarc;
retuen myHierarchy;
}
Above, the query depends on name which is a variable. It mighbe Planning Ministry, Embassy, Local Phone, etc.
Can I write the same query, but this time instead of looking to much a value in the DB, I impose my query to select a particular column.
var myVar = from orgH in db.Hierarchy
where (orgH.Level1 == "Government")
select orgH.where(level == myVariable);
return myVar;
I don't pretend that select orgH.where(level == myVariable) is even close to be valid. But that is what I want: to be able to select a column depending on a variable (i.e. the value is not known in advance like with name).
Thanks for helping
How about using DynamicQueryable?
http://weblogs.asp.net/scottgu/archive/2008/01/07/dynamic-linq-part-1-using-the-linq-dynamic-query-library.aspx
Your database is not normalized so you should start by changing the heirarchy table to, for example:
OrganizationId Parent
1 NULL
2 1
3 1
4 3
To query this you might need to use recursive queries. This is difficult (but not impossible) using LINQ, so you might instead prefer to create a parameterized stored procedure using a recursive CTE and put the query there.