I have two tables looking like this:
A B
id_attr value id id_attr value
-------------- -------------------
1 a 1 2 b
2 b 1 3 c
3 c 2 2 b
4 NULL 2 4 d
2 5 e
3 1 aaa
3 3 c
Table A is my reference table and I have multiple entries in table B. (every group of entries with the same id cosists of pairs of (id_attr,value) similiar to structure of table A). Goal is to check if entry in table A matches any of the entries in table B (one or more). One entry matches another when every attribute existing in table B under one id matches similiar attributes in table A. Also, in table A values could be NULL, but in table B not.
In example above my query should return "1", becouse only entries with id 1 fully match similiar entries in table A. Id 2 doesn't match, becouse in table A value of attribute 4 is NULL and it has an attribute which doesn`t exist in table A. Id 3 doesn't match either even if attribute 3 is similiar, but attribute 1 doesn't match.
As you can see to achieve a match not every one of the entries existing in table A should be matching, but if an attribute exists in table B then it value has to match similiar value in table A.
What is the most efficient way to achieve this result in an Oracle query?
Every help would be greatly appreciated. I can provide answers to further questions if I didn't express myself clear enough.
You can try the following:
SELECT ID, MIN(IS_OK) FROM
(
SELECT B.ID ID,
DECODE(B.VALUE, A.VALUE, 'Y', 'N') IS_OK
FROM A INNER JOIN B
ON B.ID_ATTR = A.ID_ATTR
)
GROUP BY ID;
Which will return you B's ID and a flag that indicates whether this ID is OK or not.
(Note that Decode will properly take care of the null values comparison without having to test for null values)
Related
I'm still learning SQL, so this may just be my ignorance or inability to express in a search what I'm looking for. I've spent roughly an hour searching for some variation of the title (both here and general searches on Google). I apologize, I apparently also don't know how to format here. I'll try to clean it up now that I've posted.
I have a database of customer data that I did not design. In the GUI, there are multiple tabs, and it seems like each tab earned it's own table. The tables are linked together with a field called RecordID. In one of the tables is the Customer Data tab. The way that it's organized is that a single customer record from table A can have multiple rows in table B. I only want data from column B in table B is "CompanyA" and if column A in table B = 1. Sample data is below.
Expected output:
CardNumber LastName FirstName CustomerID DataItem
------------------------------------------------------
32154 Clapton Eric 181212 CompanyA
Table A:
RecordID CardNumber LastName FirstName CustomerID
---------------------------------------------------------------
1 12345 Smith John 190201
2 12346 Jones Sandy 190202
3 23456 Petty Tom 190203
4 32154 Clapton Eric 181212
5 14728 Tyler Steven 180225
Table B:
RecordID DataID DataItem
--------------------------------
1 0 CompanyA
1 1 Yes
1 2 No
1 3 Revoked
1 4 NULL
1 5 CompanyB
2 0 CompanyB
2 1 Yes
2 2 No
2 3 NULL
2 4 24-54A
2 5 CompanyC
3 0 CompanyA
3 1 No
3 2 No
3 3 NULL
3 4 68-69B
3 5 NULL
4 0 CompanyA
4 1 Yes
4 2 Yes
5 0 CompanyB
5 1 No
5 2 No
5 5 CompanyA
The concept you're looking for is a JOIN. In this case specifically you need an INNER JOIN. Joins connects two tables together based on criteria you specify (such as matching values in fields) and merges the result into one table in the output.
Here's an example to suit your scenario:
SELECT
A.CardNumber,
A.LastName,
A.FirstName,
A.CustomerID,
B.DataItem
FROM
TableA A
INNER JOIN TableB B -- join tableB onto tableA
ON A.RecordID = B.RecordID -- in the ON clause you specify criteria by you match the fields
WHERE
B.columnA = 'CompanyA'
AND B.columnB = 1
Here's the relevant SQL Server Documentation
Also I'd advise you to potentially take a comprehensive introductory SQL tutorial, and/or find a book. A good one will introduce all of the basic, key concepts such as this to you in a logical way, then you're not grasping in the dark trying to google things for which you don't know the correct terminology.
select a.CardNumber, a.LastName, a.FirstName, a.CustomerID, b.dataitem
from tableA A inner join TableB b
on a.recordid = b.recordid
where b.columnA= 'CompanyA' and b.columnB = 1
Here is your solution,
select a.CardNumber, a.LastName, a.FirstName, a.CustomerID, b.DataItem from
tableA a
inner join tableB b
on (a.RecordID = b.RecordID)
where
b.DataItem='CompanyA'
b.RecordID=1;
Le me know if the result is not as expected
Your question is quite hard to understand, but let me give you an example that resembles the what i think you are asking.
SELECT a.*, b.DataItem FROM A a INNER JOIN B b
ON a.RecordID = b.RecordID AND
b.DataItem = `CompanyA`
At the database engine level, if you are using Microsoft technology, the most efficient structure is to use an indexed foreign key constraint on Table B, and a Primary Surrogate Key (PSK) column on Table A. The Primary Surrogate Key in your case is on the Parent table, Table A, and is called RecordID. The foreign key column with the FKC is on Table B, on the column named RecordID. Once you verify that there is a FKC (foreign key constraint on Table B, which pins both columns named RecordID between both tables on matched values), then address the GUI. At the GUI, between the tabs, you generally indicate you have a parent table with a unique set of Record IDs (one column named Record ID with absolutely unique values in each row and no empty rows on that column). There will also be child tables on each Tab in your GUI, and those are bound to the parent table in a "1 to Many (1:M)" fashion, where 1 parent has many children. Your commentary or question indicates that you also want to filter, where Record ID on the child in one of the related tabs equates to the integer value 1 on the Record ID. So, there needs to be a query somewhere:
SELECT [columns]
FROM [Table B]
INNER JOIN [Table A]
ON A.RecordID = B.RecordID
AND B.RecordID = 1;
Does that help?
Postgresql:
I have two tables 'abc' and 'xyz' in postgresql. Both tables have same 'id' columns which type is 'serial primary key;'.
abc table id column values are 1,2,3 and also xyz id column containing same values 1,2,3,4
I want to union both tables with 'union all' constraint. But I want to change 'xyz' id column values to next value of 'abc' id column last value as 1,2,3,4,5,6,7
select id from abc
union all
select id from xyz
|id|
1
2
3
1
2
3
4
my wanted resuls as
|id|
1
2
3
4
5
6
7
BETTER - Thanks to #CaiusJard
This should do it for you
select id FROM abc
UNION ALL select x.id + a.maxid FROM xyz x,
(SELECT MAX(id) as maxid from abc) a
ORDER BY id
For anyone who's doing something like this:
I had a similar problem to this, I had table A and table B which had two different serials. My solution was to create a new table C which was identical to table B except it had an "oldid" column, and the id column was set to use the same sequence as table A. I then inserted all the data from table B into table C (putting the id in the oldid field). Once I fixed the refernces to point to from the oldid to the (new)id I was able to drop the oldid column.
In my case I needed to fix the old relations, and needed it to remain unique in the future (but I don't care that the ids from table A HAVE to all be before those from table C). Depending on what your trying to accomplish, this approach may be useful.
If anyone is going to use this approach, strictly speaking, there should be a trigger to prevent someone from manually setting an id in one table to match another. You should also alter the sequence to be owned by NONE so it's not dropped with table A, if table A is ever dropped.
I have two tables, specifically, they contain standard and specific parameters respectively.
Table1:
PKParameter Name Unit
1 Temperature K
2 Length mm
3 Pressure bar
Table2:
PKSpecParam Name Unit
1 Weight kg
2 Area m2
PKParameter ans PKSpecParameter are primary keys
I would like to combine these two tables into a third table which will keep track of the primary keys so I can reference any of the parameters, regardless of the table they are from.
For example:
PKCombined PKParameter PKSpecParameter
1 1 NULL
2 2 NULL
3 3 NULL
4 NULL 1
5 NULL 2
Now I would like to use PKCombined primary key to reference parameter
Maybe there is a better way to do this, but I've just started meddling with databases.
Select a.PKParameter , a.name,a.unit,b.PKSpecParam , b.name,b.unit
from table1 a outer join table2 b on a.pkparameter=b.pkspecparam
However, this will give out null values if number of entries in pkparameter and pkspecparam dont match
I am trying to create a SQL view which contains columns from different tables; the columns are different data types.
For example;
I have table a with a column that contains usernames. The data type of this column is nvarchar.
I then have table b, which has a column that contains whether a document was printed in colour or not – the data is either yes or no. The data type of this column is bit.
I want the view to show both the above columns side by side, so I can then pull the information into Excel for reporting purposes.
I am pretty new to SQL so I am learning as I go along.
Like PM77-1 said, you'll have to have some way to tie the two tables together. For example, if your table b also has the userID of the person who printed the document out, your tables would look like this:
Table A Table B
---------------------------- -----------------------------------
userID userName docID docName inColor userID
---------------------------- -----------------------------------
1 userName1 1 docName1 1 1
2 userName2 2 docName2 0 2
3 userName3 1 docName1 1 2
3 docName3 0 1
3 docName3 1 2
2 docName2 1 3
and your query could look like this:
SELECT a.userName, b.docName, b.inColor FROM a INNER JOIN b ON a.userID = b.userID ORDER BY a.userName, b.inColor;
Currently struggling with finding a way to validate 2 tables (efficiently lots of rows for Table A)
I have two tables
Table A
ID
A
B
C
Table matched
ID Number
A 1
A 2
A 9
B 1
B 9
C 2
I am trying to write a SQL Server query that basically checks to make sure for every value in Table A there exists a row for a variable set of values ( 1, 2,9)
The example above is incorrect because t should have for every record in A a corresponding record in Table matched for each value (1,2,9). The end goal is:
Table matched
ID Number
A 1
A 2
A 9
B 1
B 2
B 9
C 1
C 2
C 9
I know its confusing, but in general for every X in ( some set ) there should be a corresponding record in Table matched. I have obviously simplified things.
Please let me know if you all need clarification.
Use:
SELECT a.id
FROM TABLE_A a
JOIN TABLE_B b ON b.id = a.id
WHERE b.number IN (1, 2, 9)
GROUP BY a.id
HAVING COUNT(DISTINCT b.number) = 3
The DISTINCT in the COUNT ensures that duplicates (IE: A having two records in TABLE_B with the value "2") from being falsely considered a correct record. It can be omitted if the number column either has a unique or primary key constraint on it.
The HAVING COUNT(...) must equal the number of values provided in the IN clause.
Create a temp table of values you want. You can do this dynamically if the values 1, 2 and 9 are in some table you can query from.
Then, SELECT FROM tempTable WHERE NOT IN (SELECT * FROM TableMatched)
I had this situation one time. My solution was as follows.
In addition to TableA and TableMatched, there was a table that defined the rows that should exist in TableMatched for each row in TableA. Let’s call it TableMatchedDomain.
The application then accessed TableMatched through a view that controlled the returned rows, like this:
create view TableMatchedView
select a.ID,
d.Number,
m.OtherValues
from TableA a
join TableMatchedDomain d
left join TableMatched m on m.ID = a.ID and m.Number = d.Number
This way, the rows returned were always correct. If there were missing rows from TableMatched, then the Numbers were still returned but with OtherValues as null. If there were extra values in TableMatched, then they were not returned at all, as though they didn't exist. By changing the rows in TableMatchedDomain, this behavior could be controlled very easily. If a value were removed TableMatchedDomain, then it would disappear from the view. If it were added back again in the future, then the corresponding OtherValues would appear again as they were before.
The reason I designed it this way was that I felt that establishing an invarient on the row configuration in TableMatched was too brittle and, even worse, introduced redundancy. So I removed the restriction from groups of rows (in TableMatched) and instead made the entire contents of another table (TableMatchedDomain) define the correct form of the data.