Hi I am new to KNIME.
I have two tables and I need to join two columns however the text of the columns are exactly the same. Ex. Document list (API) vs Document List. How would I join their data? I have tried using Joiner, however it only joins on the names that are exactly the same.
Are there any other nodes I should be using?
Related
SELECT
ost_form_entry_values.value as ost_form_entry_values__value
FROM
ost_ticket AS t
LEFT JOIN ost_form_entry
ON t.ticket_id = ost_form_entry.object_id
LEFT JOIN ost_form_entry_values
ON ost_form_entry_values.entry_id = ost_form_entry.id
WHERE ost_form_entry_values.field_id = 20
In that case, the only purpose of ost_form_entry is to connect to ost_form_entry_values for the value I'm looking for.
Is there different/better way to do that so that I'm not joining in a table that I'm not referencing in the final output?
Without changing the data model the answer is no. It's a normal thing to follow relations between tables to get the data you need.
If there's 1:1 relationship between ost_form_entry and ost_form_entry_values then you could put the object_id into the values table (that would avoid the JOIN), but I suspect that you have the so called Entity–attribute–value model which is by the way not the best way to keep unstructured data in SQL.
MySQL 5.7+ supports JSON format for example, so you could investigate that for the same purpose you are using your values table (and get rid of that table). Though, it would require the application to be adjusted in (probably) many places and if your MySQL version is older, an upgrade of the database.
My first mySQL project.
I am migrating a FileMaker DB to mySQL and having trouble with how to efficiently handle duplicate field (column) names from 3 left joined tables, combined with the fact that each table is supplying a large number of columns (50+). I understand the concept of aliasing columns. Is there a better way than to create several hundred alias lines to handle each column from each table? I've searched the site and not found a discussion of handling a large number of columns, which is common in FileMaker DBs...perhaps not in mySQL.
Current code is below, where I created the aliases for only ONE (WebPublish) of the ~50 fields for each of the 3 joined tables:
$query = "SELECT
Artwork.WebPublish as Artwork_WebPublish,
Artist.WebPublish as Artist_WebPublish,
Location.WebPublish as Location_WebPublish
FROM Review
LEFT JOIN Artwork ON Review._kf_ArtworkID = Artwork.__kp_ArtworkID
LEFT JOIN Artist ON Review._kf_ArtistID = Artist.__kp_ArtistID
LEFT JOIN Location ON Review._kf_LocationID = Location.__kp_LocationID
WHERE __kp_ReviewID = ?";
This query produces the desired response for one column from each joined table:
Array
(
[Artwork_WebPublish] => Yes
[Artist_WebPublish] => No
[Location_WebPublish] => Maybe
)
The question is whether I need to expand the aliases the long way to include 49 times more data.
Thanks for you help.
No, there's no SQL syntax for giving column aliases in a "batch" mode, for example applying the table name as a prefix to all columns (by the way, SQLite does support that feature by default).
One way to solve this is to refer to columns by ordinal position instead of by name, in whatever language you use to fetch the results.
Another solution is to define your tables with distinct column names so you avoid the name conflict. Some SQL identifiers, for example constraint names, are already required to be unique within the database they reside in, not only unique within a table. It may be a naming convention you want to use to apply the same rule to column names.
For some background, what i'm trying to do create a database that contains multiple recipes. However, it's necessary for the individual ingredients to be linked to the recipe they originally came from.
For instance, I have table containing all the individual ingredients.
And a table where the recipes are stored, minus the ingredients.
Now, i've found this article which covers how to split strings using T-SQL XML Commands, and the code that is used to do so is:
SELECT
Books.BookId,
Books.Book,
BookAuthors.AuthorId,
BookAuthors.Author
FROM Books
CROSS APPLY dbo.split(Books.Authors,',') split
INNER JOIN BookAuthors ON BookAuthors.AuthorId = split.val
The result i'm looking for would be very similar to this:
However, CROSS APPLY etc only works on MS SQL Server and my question is:
Is it possible to achieve the same, or very similar effect using MySQL?
Thanks for any help.
This should quite match what you're trying to get:
SELECT
Books.BookId,
Books.Book,
BookAuthors.AuthorId,
BookAuthors.Author
FROM Books
LEFT JOIN BookAuthors ON (find_in_set(BookAuthors.AuthorId, Books.Authors) <> 0)
Found this article very helpful: MySQL query finding values in a comma separated string
Leave a comment if you need further explanation how it works.
I have a table, tblNoComp, that has two columns, both foreign keys pointing to tblPackage.ID. The purpose of tblNoComp is to store which packages are not compatible with each other, by simply storing the ID of those packages in two columns, OneID and TwoID.
May not be the best way of storing it, but since multiple packages aren't compatible with others, it seemed to be the most logical.
Attempting to create a view that shows the tblPackage.Name for the two side by side - I have the following, but unsure how to get the TwoID Package Name..
SELECT tblNoComp.OneID, tblPackages.Package,tblNoComp.TwoID,tblPackages.Package
FROM tblNoComp, tblPackages
WHERE (tblNoComp.OneID = tblPackages.PID)
Currently the second tblPackages.Package is simply showing OneID name, not TwoID.. Not sure how to resolve?
Thank you!
--Apologies if a simple question, I've searched for an hour but haven't quite been able to describe my problem correctly.
The code you have in your comment:
SELECT
tblNoComp.OneID,
tblPackages.Package AS OneIDPackageName,
tblNoComp.TwoID,
tblPackages.Package AS TwoIDPackageName
FROM
tblNoComp
LEFT JOIN tblPackages
ON tblNoComp.OneID = tblPackages.PID
Is aliasing the columns instead of the tables. The idea behind the aliasing is to JOIN the same table twice as two different tables, using two different aliases. You're only joining it once and trying to use it twice.
You probably intent something more like this:
SELECT
tblNoComp.OneID,
tblOnePackages.Package AS OneIDPackageName,
tblNoComp.TwoID,
tblTwoPackages.Package AS TwoIDPackageName
FROM
tblNoComp
LEFT JOIN tblPackages AS tblOnePackages
ON tblNoComp.OneID = tblOnePackages.PID
LEFT JOIN tblPackages AS tblTwoPackages
ON tblNoComp.TwoID = tblTwoPackages.PID
(Note that I don't have a MySQL syntax checker handy, so this may need to be tweaked in order to run properly.)
Note that the same table is joined twice on two different keys, and that each time it's given a different alias so that it can be referenced within the SELECT clause as two separate tables.
I want to try and keep this as one query and not use PHP, but it's proving to be tough.
I have a table called applications, that stores all the applications and some basic information about them.
Then, I have a table with all the types of applications in it, and that table contains a reference to another table which stores more specific data about the specific type of application in question.
select applications.id as appid, applications.category, type.title as type, type.id as tid, type.valuefld, type.tablename
from applications
left join type on applications.typeid=type.id
left join department on type.deptid=department.id
where not isnull(work_cat)
and work_cat != ''
and applications.deleted=0
and datei between '10-04-14' and '11-04-14'
order by type, work_cat
Now, in the old version, there is another query on every single result. Over hundreds of results... that sucks.
This is the query I'd like to integrate so I can get all the data in one result row. (Old is ASP, I'm re-writing it in PHP)
query = "select sum("&adors.fields("valuefld")&") as cost, description from "&adors.fields("tablename")&" where appid = '"&adors.fields("tablename")&"'"
Prepared statements, I'm aware, are the best solution, but for now they are not an option.
You can't do this with a plain SQL query - you need to have a defined set of tables that your query is based on. The fact that your current implementation queries from whatever table is named by tablename from the first result-set means that to get this all in one query, you will have to restructure your data. You have to know what tables you're querying from rather than having it dynamic.
If the reason for these different tables is the different information stored in each requiring different record (column) structures, you might want to look into Key/Value pair storage in a large table. Once you combine the dynamically named ones into a single location you can integrate your two queries together.