Dynamic number of evaluations on a where (lambda) - linq

I'm new to Entity Framework, LINQ and lambda expressions. I need to do a search over a user's table, and I need to emulate one that already exists on a desktop application. This search gives only 1 text field, and then it takes anything that you put in it and creates a "contains" query on different users' attributes like name, last name, username, etc. The most important part is that if you put two or more words in then the search makes the query search for different words.
Example:
If I search for "ju pe" I will get "Perez, Juan", this works by the identification of blank spaces.
Using regular SQL I can build a regular string containing the query, but how can I do that using lambda?
In other words, how can I get a dynamic number of "evaluations" on the .where()? Like .Where(EV1 || EV2 || EVn)


There is neat library called LinqKit which contains predicatebuilder
Sample code:
var predicate = PredicateBuilder.True <User> ();
predicate = predicate.Or(x => x.Name.Contains("ju"));
predicate = predicate.Or(x => x.Name.Contains("pe"));
// etc ...
Users.AsExpandable().Where(predicate);
You can and/or as much as you like.


You can do this using simple Linq by building a complex Where predicate, if I understand you correctly. Please let me know if I misunderstood you! Let's say you have a string searchTermInput and users, an IEnumerable<User> for some type User with a Name string property. Then you can write:
users.Where(user => searchTermInput.Split(' ')
.All(searchTerm => user.Name.Contains(searchTerm)));
In other words: for each user, check if that user's name contains every one of the search terms and filter it out if it does not.

Related

Using except operator with property condition

I have two lists with different objects. Both objects have a string property name that I need for comparing.
I need to know what values in list A are not contained in list B based on the name property.
Would the except operator work for this case?
What would be a optimal way to achive this in Linq?

Except operator removes items based on object equality. Although you could shoehorn your scenario into Except by passing an "equality comparer" that pays attention only to Name property, the resultant code would be hard to understand.
A better approach is to make a set of names that you wish to exclude, and use that set in your query:
var excludedNames = new HashSet<string>(listB.Select(item => item.Name));
var result = listA.Where(item => !excludedNames.Contains(item.Name)).ToList();

How to use .filter() to return a match inside of an array (rethinkdb)

I want to find out how many of my students are being taught by a specific teacher. However some of the students have multiple teachers. The value of the teacher_name entry is represented as an array. The following query only shows those results where the match is exact, that is, it won't show me results where there are multiple teachers.
r.db('client').table('basic_info').filter({teacher_name: ["Andrew McSwain"]});
How can I iterate through the arrays to match if it contains the string I specified? Is there an API command for this or can I use good-ole javascript methods?

You probably want something like:
r.db('client').table('basic_info').filter(function(row) {
return row('teacher_name').contains('Andrew McSwain');
})

LINQ - OR two SqlMethods.Like clauses

I need to OR two SqlMethods.Like statements in LINQ, and I'm not sure how to accomplish it (or if it's the right way to go about it).
I've got vendor ID and vendor name fields, but I've only got a generic vendor search that allows a user to search for a vendor based on their name or ID. I also allow wildcards in the search, so I need to find vendors whose ID or name is like the user's input.
I want to do something like below, but obviously it's not correct. (EDIT: It does work as written.)
results = results.Where(p => SqlMethods.Like(p.VendorId, inputVendor.Replace("*", "%") ||
SqlMethods.Like(p.VendorName, inputVendor.Replace("*", "%"));
Background: I add where statements depending on the search parameters entered by the user, hence the results = results.Where part.
Any help would be appreciated!

It's not clear to me why this is "obviously" not correct. Presumably it's not working, otherwise you wouldn't have posted, but it's not obvious how it's not working.
I would suggest performing the replacement before the query, like this:
string vendorPattern = inputVendor.Replace("*", "%");
But then I'd expect this to work:
results = results.Where(p => SqlMethods.Like(p.VendorId, vendorPattern) ||
SqlMethods.Like(p.VendorName, vendorPattern));
Of course you're limited to where wildcards can appear in a SQL LIKE query, but that's a separate problem. (I'm not sure of the behaviour offhand if it's not at the start or end.)
If that doesn't help, please update the question with what happens when you try this.

ORA-00907 Error when using Analytic Function in a Query (PS/Query, Peopletools 8.51.12)

Query's throwing an ORA-00907 Error when I try to paste a list of values into a criteria.
Background: I'm not a developer, I'm just an end user that's studied enough to where I can write queries using PS/Query within Peoplesoft,
for my company's implementation. I work with Peoplesoft's FSCM module
(Financials and Supply Chain Management), currently on Version FSCM
8.90.08.024, using I think Oracle 11g as the base database.
I'm mostly self-taught, and the technical experts we have are busy
with database/application stuff, or they aren't familiar with my
section's specific data needs.
I should point out that I'm unable to directly write SQL statements to
Query the database. I have to use a built-in program called "PS/Query"
(also known as Query Manager) with a GUI that writes the SQL for you
and saves it as a Query that you can run to the database to extract
data. This is relevant to my question only in that:
1. I cannot create or alter views/tables
2. I cannot perform any type of SQL Statement except "SELECT"
3. I can embed PL/SQL, MetaSQL and plain SQL into Expressions
4. At this point, Query Manager is the only option I have.
PS/Query is my only experience with SQL so far, aside from Oracle's
documentation and sites like this. From my research, it's considered
extremely confining by "actual" SQL programmers.The restrictions on it
require you to do things in a manner that violates what seem to be
best practices of SQL coding.
Query Request: I have a query I've been requested to write that pulls out spend (on Vouchers and POs) against certain system-defined
Category Codes. What I'm trying to do is pull in Voucher IDs, sum the
merchandise amounts on them by Vendor and Category Code, and display
the results. Or in other words, for every unique combination of
Vendor/Category, add up all the Voucher Amounts that have that
Vendor/Category combination.
Using the SUM (Fieldname) OVER (PARTITION BY fieldname, fieldname)
syntax.
So the end result should look something like...
Code Vendor Amount
123-45 Acme $5000.00
123-45 Apple $4200.00
123-46 Acme $750.00
With that said, here's the SQL that Query Manager is displaying to get the result set I showed above:
SELECT DISTINCT D.CATEGORY_CD, D.TN_DESCR1000, C.VENDOR_ID, E.NAME1, SUM ( A.MERCH_AMT_VCHR) OVER (PARTITION BY D.CATEGORY_CD, C.VENDOR_ID),E.SETID,E.VENDOR_ID
FROM PS_PO_LINE_MATCHED A, PS_PO_LINE B, PS_PO_HDR C, PS_ITM_CAT_TBL D, PS_VENDOR E, PS_PYMNT_VCHR_XREF F
WHERE A.BUSINESS_UNIT = B.BUSINESS_UNIT
AND A.PO_ID = B.PO_ID
AND A.LINE_NBR = B.LINE_NBR
AND B.BUSINESS_UNIT = C.BUSINESS_UNIT
AND B.PO_ID = C.PO_ID
AND D.CATEGORY_ID = B.CATEGORY_ID
AND D.EFFDT =
(SELECT MAX(D_ED.EFFDT) FROM PS_ITM_CAT_TBL D_ED
WHERE D.SETID = D_ED.SETID
AND D.CATEGORY_TYPE = D_ED.CATEGORY_TYPE
AND D.CATEGORY_CD = D_ED.CATEGORY_CD
AND D.CATEGORY_ID = D_ED.CATEGORY_ID
AND D_ED.EFFDT <= SYSDATE)
AND ( F.SCHEDULED_PAY_DT >= TO_DATE('2010-07-01','YYYY-MM-DD')
AND F.SCHEDULED_PAY_DT <= TO_DATE('2011-06-30','YYYY-MM-DD'))
AND D.CATEGORY_CD LIKE :1
AND E.VENDOR_ID = C.VENDOR_ID
AND A.BUSINESS_UNIT = F.BUSINESS_UNIT
AND A.VOUCHER_ID = F.VOUCHER_ID
ORDER BY 1
Underlying Issue: This works fine, but it can only prompt on one
Category Code at a time. Category Codes are 5 digits, a 3-digit
"Class" followed by a dash and then a 2-digit "subclass. I have a list
of 375 Category Codes I need to get this Query result for.
I've set up a prompt on this version that allows entry of a Wildcard
(So 123-%%), but that's still about a hundred separate runs of the
Query. Query Manager allows use of an "In List" expression type in
Criteria, but it requires you to manually enter each entry in the
list.
I'm trying to set it up to where I can paste a plaintext copy of the
Code list into an Expression, with proper quotes/commas, and have it
evaluate that to give me a combined list of all the NIGP codes
specified. The Prompt field created by Query Manager doesn't allow
pasting of lists (as far as I know).
Attempted Solution: I viewed the page at http://peoplesoft.ittoolbox.com/groups/technical-functional/peoplesoft-other-l/create-an-expression-in-psoft-90-query-to-paste-a-list-of-emplids-2808427 and I've tried some of the answers given there, but none of them worked. That page led to me trying this modified SQL (obviously the list of codes is truncated a bit for display here):
SELECT DISTINCT D.CATEGORY_CD, D.TN_DESCR1000, C.VENDOR_ID, E.NAME1, SUM ( A.MERCH_AMT_VCHR) OVER (PARTITION BY D.CATEGORY_CD, C.VENDOR_ID),E.SETID,E.VENDOR_ID
FROM PS_PO_LINE_MATCHED A, PS_PO_LINE B, PS_PO_HDR C, PS_ITM_CAT_TBL D, PS_VENDOR E, PS_PYMNT_VCHR_XREF F
WHERE A.BUSINESS_UNIT = B.BUSINESS_UNIT
AND A.PO_ID = B.PO_ID
AND A.LINE_NBR = B.LINE_NBR
AND B.BUSINESS_UNIT = C.BUSINESS_UNIT
AND B.PO_ID = C.PO_ID
AND D.CATEGORY_ID = B.CATEGORY_ID
AND D.EFFDT =
(SELECT MAX(D_ED.EFFDT) FROM PS_ITM_CAT_TBL D_ED
WHERE D.SETID = D_ED.SETID
AND D.CATEGORY_TYPE = D_ED.CATEGORY_TYPE
AND D.CATEGORY_CD = D_ED.CATEGORY_CD
AND D.CATEGORY_ID = D_ED.CATEGORY_ID
AND D_ED.EFFDT <= SYSDATE)
AND ( F.SCHEDULED_PAY_DT >= TO_DATE('2010-07-01','YYYY-MM-DD')
AND F.SCHEDULED_PAY_DT <= TO_DATE('2011-06-30','YYYY-MM-DD'))
AND D.CATEGORY_CD = '005-00' OR D.CATEGORY_CD IN ('015-00,'' '015-06,'' '015-10,'' '615-07'')
AND E.VENDOR_ID = C.VENDOR_ID
AND A.BUSINESS_UNIT = F.BUSINESS_UNIT
AND A.VOUCHER_ID = F.VOUCHER_ID
ORDER BY 1
And the SQL above is what's giving me the ORA-00907 error. Has anyone ran into this problem before? Massive wall of text, I know. My apologies. This is my first post here and I'm trying not to leave anything relevant out.
I've got the immediate problem that spurred this question fixed,but that request is just the tip of a very large iceberg, and at some point I need to figure out a way to be able to paste plaintext lists in as criteria using Query Manager, preferably in a way that plays nice with Analytic Grouping.
TL;DR version:
Using Peoplesoft Query Manager to do an Analytic SUM with grouping using OVER, PARTITION BY. When I try to paste a list into the criteria, it throws an ORA-00907 Error.
Any help would be greatly appreciated. Thanks!

Ok, after a bit more tweaking with this, I've found what I think is the underlying issue.
The error, in this case, is two-fold. Part of it was my fault (I didn't check for Peoplesoft mangling the quotation marks I pulled from Word), and part of it was the way Query Manager interprets some kinds of functions (you have to wrap some stuff in a Case When statement to get it to evaluate properly).
First, the "My Fault" part:
Every time I was pasting in my list of test NIGP Codes, I was doing it from a file I kept saved in Microsoft Word.
Which has the probably-handy "replace straight quotes with smart quotes" feature. Peoplesoft goes bonkers when its presented a "smart quote", and will display them as upside-down question marks (there's probably a technical term, I don't know it).
So when I'd test suggestions (such as fixing the quote/comma order as suggested by #Rene Nyffenegger and #WayneH) I'd start with my base test query, add in the expressions and test it, saving it as a separate query. If they didn't work, I'd go back to the base query. That way I could iterate changes and save potential tests as different versions.
My mistake was in not saving the different versions, leaving the application and going back in. It's when you save the query, leave the page, go somewhere else in Peoplesoft, then go back to open Query Manager that it actually shows you that it's doing the character conversion. You can't see it unless you do that. Even though Query Manager is doing it. So it was throwing a character Query Manager wouldn't recognize, but not showing me the character it wouldn't recognize.
I got a new work PC recently, and I've now disabled the Smart Quotes auto-replace for future use.
Second, the "Query Manager: part:
On the version of this that I got to work, I made use of wrapping the "IN" function inside a Case statement. I've found that a lot of SQL functions, when used "plain" (as I'd define them by just copy-pasting from Oracle's definitions pages and filling in the appropriate variables) tend to give PS/Query (Query Manager) heartburn. But if you wrap them inside a CASE...WHEN...END statement that evaluates the result of the function and then build a criteria that selects based on certain values of that result, the function will work and properly display a result.
So for an example, set up this expression (like in the example from #qyb2zm302). I'm using different codes from what was in my original example, but they work the same (they're all five-digit, character-typed codes consisting of three digits, a dash, then two digits)
Case when E.CATEGORY_CD IN
('375-15', '375-30', '375-54', '375-60', '380-30','938-63')
then 'true'
else 'false'
end
And then set a criteria:
AND
Case when E.CATEGORY_CD IN
('375-15', '375-30', '375-54', '375-60', '380-30','938-63')
then 'true'
else 'false'
end
= 'true'
It'll run to completion and return any rows that have that Category Code.
If you don't want to do that, you can do like in #qyb2zm302's Method 2. The only downside to that in Query Manager is that you have to enter them into individual rows in the "List", and if you can only copy-paste 25 at a time.
Wrapping it in a Case Statement lets you paste it directly into an Expression, which is far better for larger lists.
Solutions:
The above is the code I went with that worked. It's simplifying a bit for brevity's sake, but it works.
In List works through the native Query Manager option as long as you manually-populate the list
D.CATEGORY_CD = '005-00' OR works as long as you wrap it in a Case Statement
D.CATEGORY_CD IN ('015-00','015-06','015-10','615-07') works as long as you wrap it in a Case Statement
Peoplesoft hates Smart Quotes. None of the above will work if you're copying quotation marks directly from Word, but you won't see it unless you save, leave and come back to the same query in edit mode
Formatting is important. All of the above require the proper comma/quotation formatting, as pointed out by Rene and Wayne. Meaning: ('xxx-xx', 'xxx-01','xxx-02') etc
Thanks to everyone who helped on this! I don't think I've head-desked this hard before on any question, but I guess that's part of the learning process. Since all the answers posted are valid and correct (or at least a portion of the larger "correct"), I'm going to flag them all.

The
D.CATEGORY_CD IN ('015-00,'' '015-06,'' '015-10,'' '615-07'')
part looks fishy to me
Since a '' within a string "evaluates" to a single ' the first string is
'015-00,'' '
followed by (the non-string)
015-06,
The following '' is probably the thing that the parser stumbles upon since it's pretty meaningless.
Edit try it with a D.CATEGORY_CD IN ('015-00', '015-06', '015-10', '615-07').

Following the link you posted, I see 2 methods for doing what you are trying to accomplish.
I also notice that you tried a 3rd method.
Method 1
Criteria > Add Criteria
Expression Type: Character
Length: 255
Expression Text: D.CATEGORY_CD IN ('015-00','015-06','015-10','615-07') AND 1
Condition Type: equal to
Constant: 1
Method 2
Criteria > Add Criteria
Field: D.CATEGORY_CD
Condition Type: in list
Value: 015-00','015-06','015-10','615-07
Method 3 (Your Method)
Criteria > Add Criteria
Field: D.CATEGORY_CD
Condition Type: equal to
Define Expression: '015-00' OR D.CATEGORY_CD IN ('015-00','015-06','015-10','615-07')
Question) Does the below exactly match the text you are putting the Expression box?
'015-00' OR D.CATEGORY_CD IN ('015-00','015-06','015-10','615-07')
If not, what are you putting in that box?

I think the D.CATEGORY_CD criteria are giving you the problems, I changed the double quotes to single quotes and then it still looked strange to me. I then notice the commas are inside your quotes and not between them, try making the one criteria line look like this:
before:
OR D.CATEGORY_CD IN ('015-00,'' '015-06,'' '015-10,'' '615-07'')
after:
OR D.CATEGORY_CD IN ('015-00', '015-06', '015-10', '615-07')
Also, the "IN" is an implied "OR" and I am not sure if you have parenthesis around the two D.CATEGORY_CD,
I would just put the one additional code into the IN criteria and remove the "D.CATEGORY_CD =" line:
before:
AND D.CATEGORY_CD = '005-00' OR D.CATEGORY_CD IN ('015-00', '015-06', '015-10', '615-07')
after:
AND D.CATEGORY_CD IN ('015-00', '015-06', '015-10', '615-07', '005-00')
Of course, you are already ordering by CATEGORY_CD, you could remove this criteria and pull all categories in one run (that is unless there are too many rows for excel), and then you might also want to include either VENDOR_ID or NAME1 in the ORDER BY clause.
Hope that helps you.

Query multiple elements without specifying the element name

This may be a silly question, but is it possible to make a query using XPath without specifying the element name?
Normally I would write something like
//ElementName[#id = "some_id"]
But the thing is I have many (about 40) different element types with an id attribute and I want to be able to return any of them if the id fits. But I don't want to make this call for each type individually. Is it possible to search all of them at once, regardless of the name?
I am using this in an XQuery script, if that offers any help.

use * instead of name //*[#id = "some_id"]

It might be more efficient to look directly at the #id elements - //* will work, but will initially return every node in the document and then filter!
That may not matter in a small document, of course. but here's an alternative:
//#id[.="some_id"]/..

Resources