The outline of the tables in question are as follows:
I have a table, lets call it join, that has two columns, both foreign keys to other tables. Let's call the two columns userid and buildingid so join looks like
+--------------+
| join |
|--------------|
|userid |
|buildingid |
+--------------+
I basically need to insert a bunch of rows into this table. Each user will be assigned to multiple buildings by having multiple entries in this table. So user 13 might be assigned to buildings 1, 2, and 3 by the following
13 1
13 2
13 3
I'm trying to figure out how to do this in a query if the building numbers are constant, that is, I'm assigning a group of people to the same buildings. Basically, (this is wrong) I want to do
insert into join (userid, buildingid) values ((select userid from users), 1)
Does that make sense? I've also tried using
select 1
The error I'm running into is that the subquery returns more than one result. I also attempted to create a join, basically with a static select query that was also unsuccessful.
Any thoughts?
Thanks,
Chris
Almost! When you want to insert to values of a query, don't try to put them in the values clause. insert can take a select as an argument for the values!
insert into join (userid, buildingid)
select userid, 1 from users
Also, in the spirit of learning more, you can create a table that doesn't exist by using the following syntax:
select userid, 1 as buildingid
into join
from users
That only works if the table doesn't exist, though, but it's a quick and dirty way to create table copies!
Related
I have the tables below:
tb_profile tb_mbx tb_profile_mbx tb_profile_cd
id id id_profile id_perfil
cod_mat mbx id_mbx id_cd (matches id_mbx)
concil bp
masc
I need to create a query that when validating that the id_cd 1,2,4,5
and 6 exists in tb_profile_cd, perform an insert in the
tb_profile_mbx table with the cod_matrix parameters of the tb_profile
table.
Remembering that each concil has its ID in the tb_mbx table and a
concil has many cod_mat.
Another point is that the concil id_mbx represents the id_cd of the
tb_profile_cd table.
One more point is that as I said above, that a concil has many
cod_mat. I have around 20 thousand records for each concil.
For my need, try to consult the query below, but Oracle returned an error:
insert into tb_profile_mbx values (seq_profile_mbx.nextval,
(select id from tb_profile where concil like '%NEXXERA%')
,(select id from tb_mbx where mbx like '%NEXXERA%')
,null
,null);
ORA-01427: single line subquery returns more than one line
Would there be another way to do this query?
Thanks in advance!
You can insert all matching combinations of matches using:
insert into tb_profile_mbx (id_profile, id_mbx)
select p.id, m.id
from tb_profile p join
tb_mbx m
on p.concil like '%NEXXERA%' and m.mbx like '%NEXXERA%';
I would recommend running the select to see if it returns the values you want.
You only show two columns for tb_profile_mbx, so I've only included two columns in the insert.
I have two tables, UserInfo (PrimaryKey= UID) and Relationships (PrimaryKey= RID, ForeignKey= UID).
Relationships data example:
| UID | RID |
| 2 | 3 |
| 3 | 4 |
Now, after executing an sql query, that performs some sorting on Relationships table like:
"select RID from Relationships where UID= "value"
UNION select UID from Relationships where RID= "value "
if the value = 3, i get the integer values such 2 , 4 (which means 3 has relationships with 2 and 4)
if value = 4, result = 3 (4 only has relationship with 3)
etc these resulting values are PrimaryKey values of the UserInfo table.
What i want to do is to fetch the Information of Users having the UID = 23,25,34 (These values are the result of first SQL query, so the number of values and values changes every time according to the values passed to first SQL query)
and bind it with an asp Gridview.
for this, i think i'll have to execute multiple sql queries like
select * from UserInfo where UID= 2
select * from UserInfo where UID= 4
etc
using a loop.
What i think i should do is to loop through the results of first sql query, execute the second query according to it and save the resulting recordset in another table or any sort of datasource, which is finally bind to the gridview... but i don't know how to implement it..
this is my first question in StackOverflow.. i'll try my best to further clarrify the problem if necessory..
any help would be greatly appreciatable..! :)
You can use a SQL join
select a.RID from Friendships a inner join Relationships b on a.uid=b.uid
where a.UID= "value" & b.RID="value"
order by a.uid
This will give you all records which exist in both tables A & B.More on SQL Joins
There is no need to loop as you can execute the query in a single SQL statement like
select * from UserInfo where UID IN (23, 25, 34);
On a short note, select * from table is usually a bad practise & you might want to replace it with your column names
Sorry for the lack of info -- SQL Server 2008.
I'm struggling to get a couple of column values from table A into a new row in table B for each row in A where a column isn't null.
Table A's structure is as:
UserID | ClientUserID | ClientSessionID | [and a load of other irrelevant columns)
Table B:
UserID | Name | Value
I want to create rows in table B for each non-null ClientUserID or ClientSessionID in A - using the column name as B's "Name", and column value as "B's Value".
I'm struggling to write my "unpivot" statement - just getting the syntax correct! I'm trying to follow along with some samples but can't
Here's my SQL query so far - any further help would be appreciated (just getting this SELECT is frustrating me, let alone doing the insert!)
SELECT UserID, ClientUserID, ClientSessionID FROM websiteuser WHERE ClientSessionID IS NOT null
This gives me the rows that I need to perform actions upon -- but I just can't get the syntax correct for UNPIVOTing this data and turning it into my insert.
You can unpivot records in this fashion by using UNION to get each new row:
INSERT INTO TableB (UserID, Name, Value)
SELECT UserID, 'ClientUserID' AS Name, ClientUserID AS Value
FROM TableA
WHERE ClientUserID IS NOT NULL
UNION ALL
SELECT UserID, 'ClientSessionID' AS Name, ClientSessionID AS Value
FROM TableA
WHERE ClientSessionID IS NOT NULL
I am using UNION ALL in this case as UNION implies a DISTINCT operation across the entire set, which should normally be unnecessary when pivoting unique records.
If your ClientUserID and ClientSessionID columns are not the same datatype, you may have to cast one or both to the same.
I'm trying to normalize a mysql database....
I currently have a table that contains 11 columns for "categories". The first column is a user_id and the other 10 are category_id_1 - category_id_10. Some rows may only contain a category_id up to category_id_1 and the rest might be NULL.
I then have a table that has 2 columns, user_id and category_id...
What is the best way to transfer all of the data into separate rows in table 2 without adding a row for columns that are NULL in table 1?
thanks!
You can create a single query to do all the work, it just takes a bit of copy and pasting, and adjusting the column name:
INSERT INTO table2
SELECT * FROM (
SELECT user_id, category_id_1 AS category_id FROM table1
UNION ALL
SELECT user_id, category_id_2 FROM table1
UNION ALL
SELECT user_id, category_id_3 FROM table1
) AS T
WHERE category_id IS NOT NULL;
Since you only have to do this 10 times, and you can throw the code away when you are finished, I would think that this is the easiest way.
One table for users:
users(id, name, username, etc)
One for categories:
categories(id, category_name)
One to link the two, including any extra information you might want on that join.
categories_users(user_id, category_id)
-- or with extra information --
categories_users(user_id, category_id, date_created, notes)
To transfer the data across to the link table would be a case of writing a series of SQL INSERT statements. There's probably some awesome way to do it in one go, but since there's only 11 categories, just copy-and-paste IMO:
INSERT INTO categories_users
SELECT user_id, 1
FROM old_categories
WHERE category_1 IS NOT NULL
This is staight forward I believe:
I have a table with 30,000 rows. When I SELECT DISTINCT 'location' FROM myTable it returns 21,000 rows, about what I'd expect, but it only returns that one column.
What I want is to move those to a new table, but the whole row for each match.
My best guess is something like SELECT * from (SELECT DISTINCT 'location' FROM myTable) or something like that, but it says I have a vague syntax error.
Is there a good way to grab the rest of each DISTINCT row and move it to a new table all in one go?
SELECT * FROM myTable GROUP BY `location`
or if you want to move to another table
CREATE TABLE foo AS SELECT * FROM myTable GROUP BY `location`
Distinct means for the entire row returned. So you can simply use
SELECT DISTINCT * FROM myTable GROUP BY 'location'
Using Distinct on a single column doesn't make a lot of sense. Let's say I have the following simple set
-id- -location-
1 store
2 store
3 home
if there were some sort of query that returned all columns, but just distinct on location, which row would be returned? 1 or 2? Should it just pick one at random? Because of this, DISTINCT works for all columns in the result set returned.
Well, first you need to decide what you really want returned.
The problem is that, presumably, for some of the location values in your table there are different values in the other columns even when the location value is the same:
Location OtherCol StillOtherCol
Place1 1 Fred
Place1 89 Fred
Place1 1 Joe
In that case, which of the three rows do you want to select? When you talk about a DISTINCT Location, you're condensing those three rows of different data into a single row, there's no meaning to moving the original rows from the original table into a new table since those original rows no longer exist in your DISTINCT result set. (If all the other columns are always the same for a given Location, your problem is easier: Just SELECT DISTINCT * FROM YourTable).
If you don't care which values come from the other columns you can use a (bad, IMHO) MySQL extension to SQL and do:
SELECT * FROM YourTable GROUP BY Location
which will give a result set with one row per location and values for the other columns derived from the original data in an undefined fashion.
Multiple rows with identical values in all columns don't have any sense. OK - the question might be a way to correct exactly that situation.
Considering this table, with id being the PK:
kram=# select * from foba;
id | no | name
----+----+---------------
2 | 1 | a
3 | 1 | b
4 | 2 | c
5 | 2 | a,b,c,d,e,f,g
you may extract a sample for every single no (:=location) by grouping over that column, and selecting the row with minimum PK (for example):
SELECT * FROM foba WHERE id IN (SELECT min (id) FROM foba GROUP BY no);
id | no | name
----+----+------
2 | 1 | a
4 | 2 | c