I'm trying to turn a method I have right now into a more "generic" method that returns a string. Right now, the method uses a statement like this:
var app = (from d in testContext.DAPPs
where d.sserID == (Guid)user.ProviderUserKey
select d).ToList();
I process the results of "app", add extra text etc. The piece that changes (that I need to make more "generic") is the table name (DAPPs). Is there a way I can do that, or, a better way to go around this all together?
You'll have to compose a Dynamic Linq Query.
There are a couple of ways to do this. Have a look at the following:
Dynamic Expressions in Linq to Sql
http://www.west-wind.com/Weblog/posts/143814.aspx
Using the LINQ Dynamic Query Library
http://weblogs.asp.net/scottgu/archive/2008/01/07/dynamic-linq-part-1-using-the-linq-dynamic-query-library.aspx
Related
I first created a SQL query and now I'm converting it into an AOT query in AX 2012 R3. I have everything else working except for one thing. I have a join in my SQL that is: JOIN dbo.INVENTJOURNALTABLE AS INV3 ON INV.INVENTBATCHID LIKE left(INV3.DESCRIPTION,17). In SQL this works and returns the data that I need.
I don't know how to create this join in the AOT query though.
That INV3.DESCRIPTION is a string that contains the InventBatchID.
Is there a way to do this kind of join?
In order to accomplish what you want with a Query object, it's difficult/unusual, and AX isn't designed to do this in a straight forward way and requires a very creative solution.
I would generally push towards writing a pure x++ query as I don't believe LEFT and LIKE can be natively combined, especially in a query. You can use * in the value for "like" as an option.
You may be able to accomplish using expressions in query ranges somehow.
If you must have a query, a way I can think is by combining a View, Computed Column, and a Query...and I can't guarantee it will work, but I can give you enough to have something to test with. Some of the information in this answer is pretty concentrated so look closely at everything to understand it.
Create a View, add the below computed column, then add it to a Query as pictured below. For the computed column, you need to add a new String field to the view and set the ViewMethod property to the name of the method. See here for more info about adding Computed Columns.
The Computed Column accomplishes the left(..., 17) part and you can browse the view to confirm.
The last part is trying to join either by a relation (pictured below, but it does not accomplish the like) or setting the Value property using an expression by following the link above. You may need to create a custom expression in \Classes\SysQueryRangeUtil. You have some experimenting to do to see if it works.
private static server str compColDescLeft()
{
#define.ViewName(InventJournalTableView)
#define.DataSourceName("InventJournalTable_1")
#define.FieldDescription("Description")
#define.LeftCount("17")
str sReturn;
str sLeftDesc;
DictView dictView;
dictView = new DictView(tableNum(#ViewName));
sLeftDesc = dictView.computedColumnString(#DataSourceName, #FieldDescription, FieldNameGenerationMode::FieldList, true);
sReturn = "left(" + sLeftDesc + ", " + #LeftCount + ")";
return sReturn;
}
I enjoy working with LiteDB in Xamarin.Forms. What is the best practice for getting list of objects from a table using list of ids or indexes in condition?
Currently, it looks for me like this:
_db.GetCollection<T>().FindAll().Where(q => listValues.Contains(Convert.ToInt32(q.GetProperty(idColumnName))));
listValues - list of searched ids.
idColumnName - column with indexes.
But FindAll retrives all records from LiteDB. Is there any more efficint options without full scanning?
Use the query in the Find method instead which will only retrieve entries based on your query rather than the full data set. This, according to the LiteDB's guidance, is more efficient than Linq queries on the full data returned: https://github.com/mbdavid/LiteDB/wiki/Queries
So your query would look like as follows
_d.GetCollection<T>().Find(q => listValues.Contains(Convert.ToInt32(q.GetProperty(idColumnName))))
I think you can just use collection.Query().Where("Column", 1,2,3) for this
I am working on a report, and for my data set i need to use an or statement. in SQL my query would look like:
SELECT recId, etc... FROM CustTrans
WHERE (CustTrans.Closed IS NULL AND CustTrans.Invoice IS NULL)
OR (CustTrans.Invoice IS NOT NULL)
I would translate this then into range like the following (stuck on the RecId field)
Value:
((CustTrans.Invoice == ‘’) && (CustTrans.Closed == ‘’) || (CustTrans.Invoice != ‘’))
I have found numerous places explaining that this is the proper syntax, although all of them are using the programmatic method of creating a query. I need to keep mine in the AOT so the customer can modify it later on if they want, and every combination of quotes, parens, and order still does not work. Sometimes AX will accept my range value string, but it doesn't do anything, and sometimes it will give me a random syntax error.
Is there a way to accomplish what I'm looking to do? have I missed some syntax, or does AX really not let you use OR on a query without a union and another view?
Thanks!
You can create a Query in the AOT and then over-ride the init method for the Query. Where you can put these complex SQL statements and get your work done.
So I recently came across this solution in code and was wondering if it is considered an 'acceptable' way of retrieving a single row from a Strongly Typed dataset/table.
Basically what we have is something like this:
Dim fooAdapter As New FooDataSetTableAdapters.FooTableAdapter()
Dim fooRow As FooDataSet.FooRow = CType(fooAdapter.GetData().Select("SomeFooField=50")(0), FooDataSet.FooRow)
with fooRow
..
..
end with
Although the code above works my main concern is that calling fooAdapter.GetData() will actually grab all the data in the table before applying the Select() filter which could potentially slow things down over time... Is there a cleaner way to do this or is this way of doing things fine?
Edit:
The filter criteria is not the primarykey field so calling the table's FindByFooID method will not work...
Use the dataset editor tool to create a query GetUniqueFoo with the SQL that will filter based on SomeFooField. You can run it by using fooAdapter.GetUniqueFoo(SomeFooValue).
I have list of words. I type in a word misspelled. Can I query the list using linq to get words that sounds like (soundex) the misspelled word?
I believe you can.
A quick google search came up with this link:
Code Snippet
from elt in SomeTable.AsEnumerable()
where SoundEx(elt.SomeWordsSoundExCode) == SoundEx("MyWord")
select elt;
If you want to use LINQ to SQL to query database, then you'll probably want to run the comparison on SQL side. You could use AsEnumerable, but then you'll need to implement the algorithm in C# and process the data in-memory.
I believe that LINQ to SQL doesn't provide any built-in method that would be translated to a call to the SOUNDEX function in SQL. However, you can add mapping for a user-defined SQL function (See for example this article). So, you could define your SQL function that performs the comparison and then write something like:
var db = new MyDatabaseContext();
var q = from w in db.Products
where db.SimilarSoundEx(w.Name, searchInput)
select w;