I didn't see this exactly asked, so I'm hoping it wasn't.
I have a table that has multiple columns with code variables and a table that has all lookup codes and descriptions for the whole database. Is there a way to join the lookup values so that everything stays on one row, instead of what i'm getting where one row has the race value and one row has the sex value. Thanks. I'm using TOAD but understand SQL.
Table 1
User_id Race_cd Sex_cd
101 3201 4501
102 3201 4502
103 3202 4501
104 3203 4501
Table 2
CD_Num CD_descrip
3201 White
3202 Black
3203 Asian
4501 Male
4502 Female
I played around for an hour with the joins over your tables, without an easy result.
Then I created views like this :
create view race as select * from lookup where id < 4000
create view sex as select * from lookup where id > 4000
thenafter, the select was just this easy :
select user.id, race.desc, sex.desc from users, race, sex
where user.ra = race.id
and user.se = sex.id
showing up this :
101 White Male
102 White Female
103 Black Male
104 Asian Male
May this inspire you a nice solution ! ( You will naturally have to deal with the "between value and value" predicate when creating your views. )
Related
I have seen a similar question asked How to get second highest value among multiple columns in SQL ... however the solution won't work for Microsoft Access (Row_Number/Over Partition isn't valid in Access).
My Access query includes dozens of fields. I would like to create a new field/column that would return the second highest value of 10 specific columns that are included in the query, I will call this field "Cover". Something like this:
Product Bid1 Bid2 Bid3 Bid4 Cover
Watch 104 120 115 108 115
Shoe 65 78 79 76 18
Hat 20 22 19 20 20
I can do a really long SWITCH formula such as the following equivalent Excel formula:
IF( AND(Bid1> Bid2, Bid1 > Bid3, Bid1 > Bid4), Bid1,
AND(Bid2> Bid1, Bid2 > Bid3, Bid2 > Bid4), Bid2,
.....
But there must be a more efficient solution. A MAXIF equivalent would work perfectly if MS-Access Query had such a function.
Any ideas? Thank you in advance.
This would be easier if the data were laid out in a more normalized way. The clue is the numbered field names.
Your data is currently organized as a Pivot (known in Access as crosstab), but can easily be Unpivoted.
This data is much easier to work with if laid in a more normalized fashion which is this case would be:
Product Bid Amount
--------- ----- --------
Watch 1 104
Watch 2 120
Watch 3 115
Watch 4 108
Shoe 1 65
Shoe 2 78
Shoe 3 79
Shoe 4 76
Hat 1 20
Hat 2 22
Hat 3 19
Hat 4 20
This way querying becomes simpler.
It looks like you want the maximum of the bids, grouped by Product, so:
select Product, max(amount) as maxAmount
from myTable
group by product
Really, we shouldn't be storing text fields at all, so Product should be an ID number, with associated Product Names stored once in a separate table, instead of several times in the this one, like:
ProdID ProdName
-------- ----------
1 Watch
2 Shoe
3 Hat
... but that's another lesson.
Generally speaking repeating of anything should be avoided... that's pretty much the purpose of a database... but the links below will explain than I. :)
Quackit : Microsoft Access Tutorial
YouTube : DB Planning
Microsoft : Database Design Basics
Microsoft : Database Normalization Basics
Wikipedia : Database Normalization
Right now I've got a Main table in which I am uploading data. Because the Main table has many different duplicates, I Append various data out of the Main table into other tables such as, username, phone number, and locations in order to keep things optimized. Once I have everything stripped down from the Main table, I then append what's left into a final optimized Main table. Before this happens though, I run a select query joining all the stripped tables with the original Main table in order to connect the IDs from each table, with the correct data. For example:
Original Main Table
--Name---------Number------Due Date-------Location-------Charges Monthly-----Charges Total--
John Smith 111-1111 4/3 Chicago 234.56 500.23
Todd Jones 222-2222 4/3 New York 174.34 323.56
John Smith 111-1111 4/3 Chicago 274.56 670.23
Bill James 333-3333 4/3 Orlando 100.00 100.00
This gets split into 3 tables (name, number, location) and then there is a date table with all the dates for the year:
Name Table Number Table Location Table Due Date Table
--ID---Name------ -ID--Number--------- ---ID---Location---- --Date---
1 John Smith 1 111-1111 1 Chicago 4/1
2 Todd Jones 2 222-2222 2 New York 4/2
3 Bill James 3 333-3333 3 Orlando 4/3
Before The Original table gets stripped, I run a select query that grabs the ID from the 3 new tables, and joins them based on the connection they have with the original Main table.
Select Output
--Name ID----Number ID---Location ID---Due Date--
1 1 1 4/3
2 2 2 4/3
1 1 1 4/3
3 3 3 4/3
My issue comes when I need to introduce a new table that isn't able to be tied into the Original Main Table. I have an inventory table that, much like the original Main table, has duplicates and needs to be optimized. I do this by creating a secondary table that takes all the duplicated devices out and put them in their own table, and then strips the username and number out and puts them into their tables. I would like to add the IDs from this new device table into the select output that I have above. Resulting in:
Select Output
--Name ID----Number ID---Location ID---Due Date--Device ID---
1 1 1 4/3 1
2 2 2 4/3 1
1 1 1 4/3 2
3 3 3 4/3 1
Unlike the previous tables, the device table has no relationship to the originalMain Table, which is what is causing me so much headache. I can't seem to find a way to make this happen...is there anyway to accomplish this?
Any two tables can be joined. A table represents an application relationship. In some versions (not the original) of Entity-Relationship Modelling (notice that the "R" in E-R stands for "(application) relationship"!) a foreign key is sometimes called a "relationship". You do not need other tables or FKs to join any two tables.
Explain, in terms of its column names and the values for those names, exactly when a row should turn up in the result. Maybe you want:
SELECT *
FROM the stripped-and-ID'd version of the Original AS o
JOIN the stripped-and-ID'd version of the Device AS d
USING NameID, NumberID, LocationID and DueDate
Ie
SELECT *
FROM the stripped-and-ID'd version of the Original AS o
JOIN the stripped-and-ID'd version of the Device AS d
ON o.NameID=d.NameId AND o.NumberID=d.NumberID
AND o.LocationID=d.LocationID AND o.DueDateID=d.DueDate.
Suppose p(a,...) is some statement parameterized by a,... .
If o holds the rows where o(NameID,NumberID,LocationID,DueDate) and d holds the rows where d(NameID,NumberID,LocationID,DueDate,DeviceID) then the above holds the rows where o(NameID, NumberID, LocationID, DueDate) AND d(NameID,NumberID,LocationID,DueDate,DeviceID). But you really have not explained what rows you want.
The only way to "join" tables that have no relation is by unioning them together:
select attribute1, attribute2, ... , attributeN
from table1
where <predicate>
union // or union all
select attribute1, attribute2, ... , attributeN
from table2
where <predicate>
the where clauses are obviously optional
EDIT
optionally you could join the tables together by stating ON true which will act like a cross product
This should be an easy thing to do but I seem to keep getting an extra space. Basically what I am trying to do is combine multiple columns into one column. BUT every single one of these columns might be null as well. When I combine them, I also want them to be separated by a space (' ').
What I created is the following query:
select 'All'= ISNULL(Name+' ','')+ISNULL(City+' ','')+ISNULL(CAST(Age as varchar(50))+' ','') from zPerson
and the result is:
All
John Rock Hill 23
Munchen 29
Julie London 35
Fort Mill 27
Bob 29
As you can see: there is an extra space when the name is null. I don't want that.
The initial table is :
id Name City Age InStates AllCombined
1 John Rock Hill 23 1 NULL
2 Munchen 29 0 NULL
3 Julie London 35 0 NULL
4 Fort Mill 27 1 NULL
5 Bob 29 1 NULL
Any ideas?
select 'All'= LTRIM(ISNULL(Name+' ','')+ISNULL(City+' ','')+ISNULL(CAST(Age as varchar(50))+' ','') from zPerson)
SEE LTRIM()
In the data you have posted, the Name column contains no NULLs. Instead, it contains empty strings, so ISNULL(Name+' ','') will evalate to a single space.
The simplest resolution is to change the data so that empty-strings are null. This is appropriate in your case since this is clearly your intention.
UPDATE zPerson SET Name=NULL WHERE Name=''
Repeat this for your City and Age fields if necessary.
Use TRIM() arount the ISNULL() function, or LTRIM() around the entire selected term
I cant seem to group by multiple data fields and sum a particular grouped column.
I want to group Person to customer and then group customer to price and then sum price. The person with the highest combined sum(price) should be listed in ascending order.
Example:
table customer
-----------
customer | common_id
green 2
blue 2
orange 1
table invoice
----------
person | price | common_id
bob 2330 1
greg 360 2
greg 170 2
SELECT DISTINCT
min(person) As person,min(customer) AS customer, sum(price) as price
FROM invoice a LEFT JOIN customer b ON a.common_id = b.common_id
GROUP BY customer,price
ORDER BY person
The results I desire are:
**BOB:**
Orange, $2230
**GREG:**
green, $360
blue,$170
The colors are the customer, that GREG and Bob handle. Each color has a price.
There are two issues that I can see. One is a bit picky, and one is quite fundamental.
Presentation of data in SQL
SQL returns tabular data sets. It's not able to return sub-sets with headings, looking something a Pivot Table.
The means that this is not possible...
**BOB:**
Orange, $2230
**GREG:**
green, $360
blue, $170
But that this is possible...
Bob, Orange, $2230
Greg, Green, $360
Greg, Blue, $170
Relating data
I can visually see how you relate the data together...
table customer table invoice
-------------- -------------
customer | common_id person | price |common_id
green 2 greg 360 2
blue 2 greg 170 2
orange 1 bob 2330 1
But SQL doesn't have any implied ordering. Things can only be related if an expression can state that they are related. For example, the following is equally possible...
table customer table invoice
-------------- -------------
customer | common_id person | price |common_id
green 2 greg 170 2 \ These two have
blue 2 greg 360 2 / been swapped
orange 1 bob 2330 1
This means that you need rules (and likely additional fields) that explicitly state which customer record matches which invoice record, especially when there are multiples in both with the same common_id.
An example of a rule could be, the lowest price always matches with the first customer alphabetically. But then, what happens if you have three records in customer for common_id = 2, but only two records in invoice for common_id = 2? Or do the number of records always match, and do you enforce that?
Most likely you need an extra piece (or pieces) of information to know which records relate to each other.
you should group by using all your selected fields except sum then maybe the function group_concat (mysql) can help you in concatenating resulting rows of the group clause
Im not sure how you could possibly do this. Greg has 2 colors, AND 2 prices, how do you determine which goes with which?
Greg Blue 170 or Greg Blue 360 ???? or attaching the Green to either price?
I think the colors need to have unique identofiers, seperate from the person unique identofiers.
Just a thought.
Guys, I'm new at SQL and can't figure out the "right way" to do the last part of a query. I have a table which contains a list of items and their equivalents. There are essentially twice as many rows as needed, and I'm trying to find a SQL way to select 1/2 of the entries so there are no duplicates.
Starting Table with duplicates:
Item Name EquivItem
---- ------ ----------
100 bubba 106
103 gump 109
106 shrimp 100
109 grits 103
And the resulting table would be:
Item Name EquivItem
----- ----- ----------
100 bubba 106
103 gump 109
I was using a couple nested loops in sequential code to filter out the duplicates, but finally wrote a query that works but feels like a hack.
I'm arbitrarily using a WHERE (Item < EquivItem) to select only one of the rows. The actual tables are a bit more complex and I'm afraid there may be a case where this doesn't work.
SELECT *
FROM T
WHERE Item < EquivItem
I'm trying to take some time to figure out the right way to do things before I develop too many bad habits. Any suggestions? Thanks.
Is it possible for more than two items to be equivalent, such as 100 = 103 = 106? Can this happen?
Item Name EquivItem
---- ------ ----------
100 bubba 103
103 gump 106
106 shrimp 103
As long as the the equivalents can't be chained together, and always have a 1-to-1 relationship, your solution looks perfectly fine to me.
If this scenario can happen, I would first scrub the data to make sure that all the EquivItems refer to the lowest Item ID in the chain... and then your original query would still do the job.