I have table A with an id column and a bunch of others. I also have table B which has an id column like table A and also another column called countries. However, not all id in table A are in table B. I want to insert a new column into table A called countries2 that basically inserts the countries from table B that corresponds to the ids in both tables. If a specific id from A does not exist in B, then it always puts in the VARCHAR 'none' into countries2.
So for example if Table A has the ids 1, 2, 3, 4 and table B looks like:
id--country
1---'foo1'
3---'foo2'
I want table A to become something like:
id--country2--other original data from table A
1---'foo1'--...
2---'none'--...
3---'foo2'--...
4---'none'--...
You need to first alter your TableA to add an extra column (i.e yourNewColumn) of type varchar/varchar2
to add the column try something like
ALTER TABLE TableA ADD COLUMN yourNewColumn varchar(10);
Then you can use something like below to update TableA
UPDATE TableA
SET yourNewColumn = ISNULL(TableB.countries, 'none')
FROM TableA
LEFT JOIN TableB ON TableA.id = TableB.id
The ISNULL function in PostgreSQL might be something like
SET yourNewColumn = CASE WHEN TableB.countries IS NULL THEN 'none' ELSE TableB.countries END
Related
Just to level set: i'm working within a Vertica database using SQL.
Let's say i have two tables: Table A and Table B. Let's also say that Table A is my final/master table used for data vis within Tableau (or something akin), and that Table B feeds certain columns into Table A based on matches within a tertiary table, Table C (which is not relevant to this conversation).
As is, Table A has columns:
ProgramName [varchar(50)]
CustomerName [varchar(50)]
Total_Cost [numeric(18,4)]
As is, Table B has columns:
CustomerCode [varchar(10)]
Total_Cost [numeric(18,4)]
What I would like to do is update Table A's CustomerName column to equal CustomerCode in Table B where the columns of total_cost_dollars equal each other across tables.
I've run this left join query to ensure that, when I do update Table A's CustomerName to equal CustomerCode, the total cost columns are exact/true matches for my entire data set.
SELECT
A.ProgramName,
A.CustomerName,
A.total_cost_dollars,
B.CustomerCode,
B.total_cost_dollars
FROM
TableA A
LEFT JOIN
TableB B
ON
B.total_cost_dollars = A.total_cost_dollars
WHERE
A.CustomerName IS NULL;
Any idea on how to solve this problem?
Since Vertica supports merge query, you can use merge statement:
merge into TableA A
using TableB B
ON (B.total_cost_dollars = A.total_cost_dollars)
when matched then
update
set
A.CustomerName = B.CustomerCode
where
A.CustomerName IS NULL;
I have tableA with the columns ID, ColumnHeader, Value.
I'm trying to update tableB where ID, and the value in tableB.ColumnHeader with tableB.Value.
Essentially, the column headers for tableB are in a column in Table A and not column headers themselves.
I'm stuck on specifying the table name. For example, how do I run this query when I only have tablename.____ where the blank is in a column in a separate table?
update tableB set table.____ .....
As seen in the screenshot below, in Table B, 4 should become 1, and 8 should become 2, and 12 should become 3. Thanks so much.
this is a example from Northwind database:
UPDATE dbo.Products
SET dbo.Products.CategoryID = c.CategoryID
FROM Products
INNER JOIN dbo.Categories c ON dbo.Products.CategoryID = c.CategoryID
I am not getting which table and column you want to update with which table and column.
also relationship is not clear.
This doesn't make sense to me. Are you trying to update table B or A? Are there like values in table B and A that you want updated?
The basic code is as shown below:
update tableb
set column id = 'value you're updating'
where column id = 'value you're looking for' --always make this unique like a key etc.
I need to update one column called Ident in table a to be a value from table b, as shown below. Both the change and keep values in table b are valid Idents which will appear in table a. I need to find the Change value in table b in table a, and then change the value in table a to the Keep value in table b.
Statement i'm using is:
update p set p.ident=t.keep
from pclscvq p inner join #tmp t on (p.ident=t.change)
where t.change=p.ident
Table B:
Change Keep
0004P 0004R
0004X 0004Y
00055 00056
00057 00058
0005B 0005C
0005K 0005L
0005Z 00060
00065 00066
0006X 0006Y
00070 00071
Very much stuck.
Using Advantage SQL
I have two tables.Table A has 4 columns. And table B has two columns.I want to insert value of one column of tabel A from one column of table B based on condtion if id matches.
how i can do this ? For example if [Movieid] in 1st table =[IMDBid] in second table then insert [count] of table 1=[CB] in table 2.
i want to do it once for full table.
[column] -> these are colums
i m using sql server.
Tabel 1 : Movieid,count,
Tabel 2: IMDBid, CB
Results which i want: i want to insert values of CB column in count where Movieid=IMDBid
Tabel 1 :
(Nick Id,MovieId,Rating,MovId)-> (1,4972,6.25,?)(1,24216,7.25,?)
Tabel 2 :
(Imdbid,Title,ImdbPyId,Id)-> (4972,hello,32450,1)(24216,hi,62450,2)
Insert /fill value of MovId(tabel1) using values Id(tabel2)where MovieId(tabel1)==Imdbid(tabel2)
You can do it like,
UPDATE tabl1
SET count = (SELECT CB FROM tabl2 WHERE IMDBid = Movieid)
But it is gonna blow up if you have multiple values returning from the subquery.
So make sure to use the appropriate function to get the single value from that subquery whichever meets your requirements.
If your tables have 1:1 relationship then it should be fine. But if it is 1:n then you need to use either aggragate functions or the TOP 1 clause in that subqyery.
solution is UPDATE tabl1
SET count = (SELECT CB FROM tabl2 WHERE IMDBid = Movieid)
Table A has a population of names and unique ids. Table B has the same unique ids and names. The majority of the names in table B are null, but some have an updated name. I want to merge the two tables so I get the old names from table A and new names from table B if they exist. Basically layer table B on top of table A to capture changes to the names.
I've done something like this in sas, but am having a problem in Access. merging via sas is no longer an option. can this be done in access?
You can do this in SQL using theIIFandISNULLfunctions to select the name from the correct table (from TableA if TableB is null, otherwise from TableB). If your tables has two fields:(id,the_name)a query could look like this:
SELECT a.id, IIF(ISNULL(b.the_name), a.the_name, b.the_name) AS the_name
INTO TableC
FROM TableA a
INNER JOIN TableB b ON a.id = b.id