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Customized Auto-Number IDs for tables?
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First of all, I am quite new to SQL and Microsoft Access.
I am setting a database in Access. My database collects information from four different departments. I store my data through forms. My main table (Business) stores information (department) using a Combo Box saving a number instead of text.
I want to have a column (similar to CODE ID already available in the table above) which shows the initial letter from a field (name Department) + a number.
Ie. In table "Business", I want to display a Code ID which contains the initials of column Department plus a number code (department order number ascending). I want to have this every time i add information.
+===============+=================+=========+==+
| DEPARTMENT | PARTNER | CODE ID | |
+===============+=================+=========+==+
| Data_Analysis | John Doe | D001 | |
+---------------+-----------------+---------+--+
| Marketing | Jane Doe | M001 | |
+---------------+-----------------+---------+--+
| Finance | Alex Mustermann | F001 | |
+---------------+-----------------+---------+--+
| Operations | Juan Perez | O001 | |
+---------------+-----------------+---------+--+
| Finance | Barack Trump | F002 | |
+---------------+-----------------+---------+--+
| Finance | Mark Merkel | F003 | |
+---------------+-----------------+---------+--+
| Marketing | Peggy Hilton | M002 | |
+---------------+-----------------+---------+--+
| Operations | Max Mustermann | O002 | |
+---------------+-----------------+---------+--+
| Operations | | OXXX | |
+---------------+-----------------+---------+--+
The values in column CODE ID are those I would like to have display every time I add a new row (new department order). I need this type of code for tracking my number of orders in each department and use it as a unique code for any inquires with partners. I dont want to have it as the primary key id.
Thanks in advance!
If you rethink the schema slightly it becomes trivial; instead of having the column with the ID and code combined, just keep a running count when inserting:
INSERT INTO business(department, name, code) SELECT Forms!Department, Forms!Name, COUNT(*)+1 FROM business WHERE name=Forms!Name
Then when you pull the information out:
SELECT department, name, LEFT(1, department) & code
Related
I’ve been working on a Windows Form App using vb.net that retrieves information from a SQL database. One of the forms, frmContract, queries several tables, such as Addresses, and displays them in various controls, such as Labels and DataGridViews. Every year, the customer’s file is either renewed or expired, and I’m just now realizing that a change committed to any record today will affect the information displayed for the customer in the past. For example, if we update a customer’s mailing address today, this new address will show up in all previous customer profiles. What is the smartest way to avoid this problem without creating separate rows in each table with the same information? Or to put it another way, how can versions of a customer’s profile be preserved?
Another example would be a table that stores customer’s vehicles.
VehicleID | Year | Make | Model | VIN | Body
---------------------------------------------------------------
1 | 2005 | Ford | F150 | 11111111111111111 | Pickup
2 | 2001 | Niss | Sentra | 22222222222222222 | Sedan
3 | 2004 | Intl | 4700 | 33333333333333333 | Car Carrier
If today vehicle 1 is changed from a standard pickup to a flatbed, then if I load the customer contract from 2016 it will also show as flatbed even though back then it was a pickup truck.
I have a table for storing individual clients.
ClientID | First | Last | DOB
---------|----------|-----------|------------
1 | John | Doe | 01/01/1980
2 | Mickey | Mouse | 11/18/1928
3 | Eric | Forman | 03/05/1960
I have another table to store yearly contracts.
ContractID | ContractNo | EffectiveDate | ExpirationDate | ClientID (foreign key)
-----------|------------|---------------|-------------------|-----------
1 | 13579 | 06/15/2013 | 06/15/2014 | 1
2 | 13579 | 06/15/2014 | 06/15/2015 | 1
3 | 24680 | 10/05/2016 | 10/05/2017 | 3
Notice that the contract number can remain the same across different periods. In addition, because the same vehicle can be related to multiple contracts, I use a bridge table to relate individual vehicles to different contracts.
Id | VehicleID | ContractID <-- both foreign keys
---|-----------|------------
1 | 1 | 1
2 | 3 | 1
3 | 1 | 2
4 | 3 | 2
5 | 2 | 3
6 | 2 | 2
When frmContract is loaded, it queries the database and displays information about that particular contract year. However, if Vehicle 1 is changed from pickup to flatbed right now, then all the previous contract years will also show it as a flatbed.
I hope this illustrates my predicament. Any guidance will be appreaciated.
Some DB systems have built-in temporal features so you can keep audit history of rows. Check to see if your DB has built-in support for this.
I have 4 columns in my non-decomposed, non-normalized Job Application table which are all Nullable, for example my table is:
Name | SSN | Education | City | Job Applied | Post | Job Obtained | Post Obtained
John. | 123 | High School | LA | USPS | MailMan | USPS | MailMan
John. | 123 | High School | LA | Dept. of Agri | Assistant | *null* | *null*
Sam. | 123 | BS | NY | Intel | QA Analyst | Intel | QA Analyst
The first 4 Columns are non-nullable so I can easily determine Functional Dependencies between them.
The last 4 columns, can or cannot have values depending on if a person has got a job and also depending on if he/she has applied for a job.
My question is: Can I have Functional Dependencies on Nullable Columns either them being on the LHS or the RHS.
The answer should be yes, please see:
http://en.wikipedia.org/wiki/Functional_dependency
I guess this query is a little basic and I should know more about SQL but haven't done much with joins yet which I guess is the solution here.
What I have is a table of people and a table of job roles they hold. A person can have multiple jobs and I wish to have one set of results with a row per person containing their details and their job roles.
Two example tables (people and job_roles) are below so you can understand the question easier.
People
id | name | email_address | phone_number
1 | paul | paul#example.com | 123456
2 | bob | bob#example.com | 567891
3 | bart | bart#example.com | 987561
job_roles
id | person_id | job_title | department
1 | 1 | secretary | hr
2 | 1 | assistant | media
3 | 2 | manager | IT
4 | 3 | finance clerk | finance
4 | 3 | manager | IT
so that I can output each person and their roles like such
Name: paul
Email Address: paul#example.com
Phone: 123456
Job Roles:
Secretary for HR department
Assistant for media department
_______
Name: bob
Email address: bob#example.com
Phone: 567891
Job roles:
Manager for IT department
So how would I get each persons information (from the people table) along with their job details (from the job_roles table) to output like the example above. I guess it would be some kind of way of merging their jobs and their relevant departments into a jobs column that can be split up for output, but maybe there is a better way and what would the sql look like?
Thanks
Paul
PS it would be a mySQL database if that makes any difference
It looks like a straight-forward join:
SELECT p.*, j.*
FROM People AS p INNER JOIN Roles AS r ON p.id = r.person_id
ORDER BY p.name;
The remainder of the work is formatting; that's best done by a report package.
Thanks for the quick response, that seems a good start but you get multiple rows per person like (you have to imagine this is a table as you don't seem to be able to format in comments):
id | Name | email_address | phone_number | job_role | department
1 | paul | paul#example.com | 123456 | secretary | HR
1 | paul | paul#example.com | 123456 | assistant | media
2 | bob | bob#example.com | 567891 | manager | IT
I would like one row per person ideally with all their job roles in it if that's possible?
It depends on your DBMS, but most available ones do not support RVAs - relation-valued attributes. What you'd like is to have the job role and department part of the result like a table associated with the user:
+----+------+------------------+--------------+------------------------+
| id | Name | email_address | phone_number | dept_role |
+----+------+------------------+--------------+------------------------+
| | | | | +--------------------+ |
| | | | | | job_role | dept | |
| 1 | paul | paul#example.com | 123456 | | secretary | HR | |
| | | | | | assistant | media | |
| | | | | +--------------------+ |
+----+------+------------------+--------------+------------------------+
| | | | | +--------------------+ |
| | | | | | job_role | dept | |
| 2 | bob | bob#example.com | 567891 | | manager | IT | |
| | | | | +--------------------+ |
+----+------+------------------+--------------+------------------------+
This accurately represents the information you want, but is not usually an option.
So, what happens next depends on your report generation tool. Using the one I'm most familiar with, (Informix ACE, part of Informix SQL, available from IBM for use with the Informix DBMSs), you would simply ensure that the data is sorted and then print the name, email address and phone number in the 'BEFORE GROUP OF id' section of the report, and in the 'ON EVERY ROW' section you would process (print) just the role and department information.
It is often a good idea to separate the report formatting from the data retrieval operations; this is an example of where it is necessary unless your DBMS has unusual features to help with the formatting of selected data.
Oh dear that sounds very complicated and not something I could run easily on a mySQL database in a PHP page?
The RVA stuff - you're right, that is not for MySQL and PHP.
On the other hand, there are millions of reports (meaning results from queries that are formatted for presentation to a user) that do roughly this. The technical term for them is 'Control-Break Report', but the basic idea is not hard.
You keep a record of the 'id' number you last processed - you can initialize that to -1 or 0.
When the current record has a different id number from the previous number, then you have a new user and you need to start a new set of output lines for the new user and print the name, email address and phone number (and change the last processed id number). When the current record has the same id number, then all you do is process the job role and department information (not the name, email address and phone number). The 'break' occurs when the id number changes. With a single level of control-break, it is not hard; if you have 4 or 5 levels, you have to do more work, and that's why there are reporting packages to handle it.
So, it is not hard - it just requires a little care.
RE:
I was hoping SQL could do something
clever and join the rows together
nicely so I had essentially a jobs
column with that persons jobs in it.
You can get fairly close with
SELECT p.id, p.name, p.email_address, p.phone_number,
group_concat(concat(job_title, ' for ', department, ' department') SEPARATOR '\n') AS JobRoles
FROM People AS p
INNER JOIN job_roles AS r ON p.id = r.person_id
GROUP BY p.id, p.name, p.email_address, p.phone_number
ORDER BY p.name;
Doing it the way you're wanting would mean the result set arrays could have infinite columns, which would be very messy. for example, you could left join the jobs table 10 times and get job1, job2, .. job10.
I would do a single join, then use PHP to check if the name ID is the same from 1 row to the next.
One way might be to left outer join the tables and then load them up into an array using
$people_array =array();
while($row1=mysql_fetch_assoc($extract1)){
$people_array[] = $row1;
}
and then loop through using
for ($x=0;$x<=sizeof($people_array;)
{
echo $people_array[$x][id];
echo $people_array[$x][name];
for($y=0;$y<=$number_of_roles;$y++)
{
echo $people_array[$x][email_address];
echo $people_array[$x][phone_number];
$x++;
}
}
You might have to play with the query a bit and the loops but it should do generally what you want.For it to work as above every person would have to have the same number of roles, but you may be able to fill in the blanks in your table
I have problem with unique rows in db table, now it is posible to do that:
id | Name | LastName | City
-------------------------------------
1 | John | Moore | London
2 | John | Moore | London
when i use UNIQUE attribute in all columns i have errors inserting second Moore even it is different Name :/
how use UNIQUE (or maybe INDEX?) to do something like that in my table in db:
id | Name | LastName | City
-------------------------------------
1 | John | Moore | London
2 | Jake | Moore | London
3 | John | Keen | London
4 | John | Moore | London //but good error when inserting the same row
Sorry if question is easy, but i am beginner at sql, and have problems with find some good example with using a UNIQUE like a want:/
or maybe I must just before inserting a new row selecting a table from db and check if it exist?
Remove the unique index on the individual column and make it on both columns together, like this:
CREATE UNIQUE INDEX ixFullName ON yourTable (LastName, Name);
I've created a form in PHP that collects basic information. I have a list box that allows multiple items selected (i.e. Housing, rent, food, water). If multiple items are selected they are stored in a field called Needs separated by a comma.
I have created a report ordered by the persons needs. The people who only have one need are sorted correctly, but the people who have multiple are sorted exactly as the string passed to the database (i.e. housing, rent, food, water) --> which is not what I want.
Is there a way to separate the multiple values in this field using SQL to count each need instance/occurrence as 1 so that there are no comma delimitations shown in the results?
Your database is not in the first normal form. A non-normalized database will be very problematic to use and to query, as you are actually experiencing.
In general, you should be using at least the following structure. It can still be normalized further, but I hope this gets you going in the right direction:
CREATE TABLE users (
user_id int,
name varchar(100)
);
CREATE TABLE users_needs (
need varchar(100),
user_id int
);
Then you should store the data as follows:
-- TABLE: users
+---------+-------+
| user_id | name |
+---------+-------+
| 1 | joe |
| 2 | peter |
| 3 | steve |
| 4 | clint |
+---------+-------+
-- TABLE: users_needs
+---------+----------+
| need | user_id |
+---------+----------+
| housing | 1 |
| water | 1 |
| food | 1 |
| housing | 2 |
| rent | 2 |
| water | 2 |
| housing | 3 |
+---------+----------+
Note how the users_needs table is defining the relationship between one user and one or many needs (or none at all, as for user number 4.)
To normalise your database further, you should also use another table called needs, and as follows:
-- TABLE: needs
+---------+---------+
| need_id | name |
+---------+---------+
| 1 | housing |
| 2 | water |
| 3 | food |
| 4 | rent |
+---------+---------+
Then the users_needs table should just refer to a candidate key of the needs table instead of repeating the text.
-- TABLE: users_needs (instead of the previous one)
+---------+----------+
| need_id | user_id |
+---------+----------+
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 1 | 2 |
| 4 | 2 |
| 2 | 2 |
| 1 | 3 |
+---------+----------+
You may also be interested in checking out the following Wikipedia article for further reading about repeating values inside columns:
Wikipedia: First normal form - Repeating groups within columns
UPDATE:
To fully answer your question, if you follow the above guidelines, sorting, counting and aggregating the data should then become straight-forward.
To sort the result-set by needs, you would be able to do the following:
SELECT users.name, needs.name
FROM users
INNER JOIN needs ON (needs.user_id = users.user_id)
ORDER BY needs.name;
You would also be able to count how many needs each user has selected, for example:
SELECT users.name, COUNT(needs.need) as number_of_needs
FROM users
LEFT JOIN needs ON (needs.user_id = users.user_id)
GROUP BY users.user_id, users.name
ORDER BY number_of_needs;
I'm a little confused by the goal. Is this a UI problem or are you just having trouble determining who has multiple needs?
The number of needs is the difference:
Len([Needs]) - Len(Replace([Needs],',','')) + 1
Can you provide more information about the Sort you're trying to accomplish?
UPDATE:
I think these Oracle-based posts may have what you're looking for: post and post. The only difference is that you would probably be better off using the method I list above to find the number of comma-delimited pieces rather than doing the translate(...) that the author suggests. Hope this helps - it's Oracle-based, but I don't see .