linq to entity Contains() and nested queries - linux

i've a trouble with linq, i'll explain on example :
i have a database table called Employee which got FirstName and LastName columns,
and a method to search employees which gets a nameList list as argument, the elements in this list are names formatted like this one "Fred Burn", or this1 "Grim Reaper",
already tryed these approaches with no luck =[
//just all employees
var allData = from emp in Context.Employee select emp;
var test1 = from emp in allData
where(emp.FirstName + " " + emp.LastName).Contains
("" + ((from n in nameList select n).FirstOrDefault()))
select emp;
var test2 = (from emp in allData
where (emp.FirstName + " " + emp.LastName)
== ((from n in nameList select n).FirstOrDefault())
select emp);
var test3 = from emp in allData
where (from n in nameList select n).Contains
(emp.FirstName + " " + emp.LastName)
select emp;
first and second queries give : {"Unable to create a constant value of type 'Closure type'. Only primitive types ('such as Int32, String, and Guid') are supported in this context."} exceptionand third : {"LINQ to Entities does not recognize the method 'Boolean Contains[String](System.Collections.Generic.IEnumerable`1[System.String], System.String)' method, and this method cannot be translated into a store expression."}
would be glad to hear your suggestions :)
Thank You!
p.s.
yea i know it's possible to split names in list and compare them separately, but still curious why wont these queries work.

I assume nameList in this case is an in memory collection and that you are trying to use the LINQ to SQL trick creating a SQL "IN" clause inside of the Entity Framework. Unfortunately, EF doesn't support this syntax (yet). Depending on the number of records you are trying to match, you may be able to run separate queries for each child you are desiring. Alternatively, you could build an entitysql query using concatenation to append the multiple items from the nameList as separate OR clauses in the WHERE operation.

Related

Kentico 10 ObjectQuery join multiple tables

I am basically trying to run a query that gives me all the Users that have purchased a product with a particular SKU. Essentially this SQL here:
SELECT u.FirstName, u.LastName, u.Email
FROM COM_OrderItem oi INNER JOIN COM_Order o ON oi.OrderItemOrderID = o.OrderID
INNER JOIN COM_Customer c ON o.OrderCustomerID = c.CustomerID
INNER JOIN CMS_User u ON c.CustomerUserID = u.UserID
WHERE oi.OrderItemSKUID = 1013
I was trying to use the ObjectQuery API to try and achieve this but have no idea how to do this. The documentation here does not cover the specific type of scenario I am looking for. I came up with this just to try and see if it works but I don't get the three columns I am after in the result:
var test = OrderItemInfoProvider
.GetOrderItems()
.Source(orderItems => orderItems.Join<OrderInfo>("OrderItemOrderID", "OrderID"))
.Source(orders => orders.Join<CustomerInfo>("OrderCustomerID", "CustomerID"))
.Source(customers => customers.Join<UserInfo>("CustomerUserID", "UserID"))
.WhereEquals("OrderItemSKUID", 1013).Columns("FirstName", "LastName", "Email").Result;
I know this is definitely wrong and I would like to know the right way to achieve this. Perhaps using ObjectQuery is not the right approach here or maybe I can somehow just use raw SQL. I simply don't know enough about Kentico to understand the best approach here.
Actually, the ObjectQuery you created is correct. I tested it and it is providing the correct results. Are you sure that there are indeed orders in the system, which contain a product with SKUID 1013 (you can check that in the COM_OrderItem database table)?
Also, how are you accessing the results? Iterating through the results should look like this:
foreach (DataRow row in test.Tables[0].Rows)
{
string firstName = ValidationHelper.GetString(row["FirstName"], "");
string lastName = ValidationHelper.GetString(row["LastName"], "");
string email = ValidationHelper.GetString(row["Email"], "");
}

How to bind variables inside collection literals in Cassandra 3.0 using java?

I have a java application in which I am parsing data and updating it to my Cassandra 3.0 database. I have been successful so far until it comes to my columns with user-defined types.
My attempt:
String statement_update = "UPDATE table SET "
+ "elements = elements + [{name: ? , associations: []}]"
+ " WHERE id = ?
elements is a user defined type in my Cassandra 3.0 Database.
It is composed of name (data type: text) and associations (data type: list).
PreparedStatement prepared_update = session.prepare(statement_update);
bound_update = prepared_update.bind(name, id);
variables name and id are of type String.
I have been trying to use a prepared statement to update my table with newly parsed data; however after the data is parsed I am having trouble adding more elements to my elements column. I get error: “Invalid list literal for elements: bind variables are not supported inside collection literals.” How do I work around or resolve this?
I have tried ways of changing the statement_update to “UPDATE table SET elements = elements + ? WHERE id = ?”, but I don’t know what kind of list (or even if its a list) to add to my bind statement.
What is needed to satisfy my user-defined type: elements?
Try another update notation:
session := getGocqlSession()
err := session.Query(
"UPDATE table SET mymapcolumn[?] = ? WHERE rowkey = ?",
mapKey, mapValue, rowKey,
).Exec()
This worked for me.
I have done this on Go, but maybe this approach will help.

Using DbContext.FindBy not with a PK

Objective:
I have a table called Publication that contains Id, RecordId, EntityType and a couple other columns. I select all the records that need to be published to another database from that table. I then loop that collection to process the records and move the records to the other db.
Background:
The EntityType column is used to Identify the Set that the context needs to retrieve. I also use reflection to create a object of that type to see if it implements a certain type of interface. If the record being processed does implement that interface then I know that the RecordId for that record in the Publication table is not a PK in the Set() but rather a FK.
this code works fine when I am going after the PK values for EntityTypes that do not inherit the specific interface.
object authoringRecordVersion = PublishingFactory.AuthoringContext.Set(recordType.Entity.GetType()).Find(record.RecordId);
Problem:
DbContext.Set(EntityType).Find(PK) goes after the PrimaryKey value. How can I tell Set() to search like this sudo code example since 'Where' is not allowed
object authoringRecordVersion = PublishingFactory.AuthoringContext.Set(recordType.Entity.GetType()).Where(c => c.HeaderRecordId == record.RecordId)
Update:
I am working on Implementing the following. Will advise results tomorrow
var sql = "SELECT * from " + record.Entity + " WHERE HeaderRecordId = '" + record.RecordId + "'";
authoringRecordVersion = PublishingFactory.AuthoringContext.Set(recordType.Entity.GetType()).SqlQuery(sql).AsNoTracking();
.SqlQuery(sql).AsNoTracking();
does work effectively. Don't know why I didn't see this earlier.

Creating an associative array using a while loop for select list?

I am dynamically generating a selectlist in Drupal and I want to create an associative array to populate the node ID as the value, and the title of the node as the option.
By default, it makes the value for each option the index of the select list. This is no good because the select list is dynamic, meaning the values won't be in the same order.
I used drupal_map_assoc to make the value the same as the option, but I have queries based on the value stored in this field, so if someone updates the value stored, the queries won't match.
<option value="Addison Reserve Country Club Inc.">Addison Reserve Country Club Inc.</option>
I want to replace the value with the Node ID also pulled with the query.
$sql = 'SELECT DISTINCT title, nid FROM {node} WHERE type = \'accounts\' ';
$result = db_query($sql);
while ($row = db_fetch_array($result)) {
$return[] = $row['title'];
//Trying to do something like 'Addison Reserve Country Club' => '2033' - where 2033 is the nid
}
$return = drupal_map_assoc($return);
I think you just want to do this inside the loop:
$return[$row['nid']] = $row['title'];
Based on your comment, you would also want to do an array_flip() right after the loop, but I think your comment may just have it backwards.

Calling an SQL function from a Subsonic.Select

I asked the following question on the subsonic forum, but only seemed to get one response, so I thought I'd post up here as well to see if anyone could shed some more light on the problem...
I wish to create the following SQL statement through SubSonic using the Select tool (or Query tool) .. it uses a custom function called "SPLIT()":
SELECT * FROM VwPropertyList
WHERE VwPropertyList.idCreatedBy = 123
AND VwPropertyList.idCounty = 45
AND 29 IN (SELECT Item FROM SPLIT(DistrictGroupList, ','))
(the last part of this SQL uses the SPLIT function)
My subsonic equivalent looks like the following...
Dim mySelect As New SubSonic.Select
mySelect.From(VwPropertyList.Schema)
mySelect.Where(VwPropertyList.Columns.IdCreatedBy).IsEqualTo(123)
mySelect.And(VwPropertyList.Columns.IdCounty).IsEqualTo(45)
mySelect.And(29).In(New SubSonic.Select("Item").From("SPLIT("
&
VwPropertyList.Columns.DistrictGroupList
& ", ',')"))
This doesn't work though due to the last part .. how can I add "AND 29 IN (SELECT Item FROM SPLIT(DistrictGroupList, ','))" into my Subsonic.Select ?
The response I got from the subsonic forum suggested I do away with Subsonic.Select and replace with hard-coded InlineQuery() statements .. like:
Dim SQL as String = "Select " &
VwPropertyList.Columns.Item SQL = SQL
& " From " &
VwPropertyList.Schema.TableName SQL =
SQL & " Where " &
VwPropertyList.Columns.IdCreatedBy & "
= #CreatedBy " SQL = SQL & " And " & VwPropertyList.Columns.IdCounty & " =
#County " SQL = SQL & " And
#DistrictGroup IN (Select Item From
SPLIT(DistrictGroupList,',')"
Items =
SubSonic.InlineQuery().ExecuteTypedList(Of
MyItem)(SQL, 123,45,29)
I would prefer to use SubSonic.Select if possible though so that I can avail of the paging functionality etc.
Any ideas?
You could do John's suggestion or you could write the SQL using our InlineQuery - which allows you to write raw SQL and pass in params:
var qry=new InlineQuery("SELECT * FROM table WHERE column=#param",value)
You could try to use the original query object (pre 2.1) like so (untested, from memory):
Query q = new Query(VwPropertyList.Schema.TableName);
q.WHERE("29 IN (SELECT Item FROM SPLIT(DistrictGroupList, ','))");
// pass q.ExecuteReader() to the Load() method of your view.
I would suggest that you use the original Query object as you are looking to get paging. Inline Query does not have any methods that allow paging.
If you absolutely wanted to use Subsonic.Select you could mesh the two ideas and run an Inline Query to get the list of values and then use a Regular Subsonic.Select and pass the retrieved values to the select case but then you would be making two trips to the db.
On a side note I prefer reading Subsonic.Select statements written using the fluent interface that it is namely
SubSonic.Select.AllColumnsFrom()
.Where(VwPropertyList.Columns.IdCreatedBy).IsEqualTo(123)
.And(VwPropertyList.Columns.IdCounty).IsEqualTo(45)
.ExecuteAsCollection();
thanks for the responses.
I ended up doing InlineQuery and just re-wrote the paging code that's normally produced by Subsonic.Select ... not the best solution but it seems to work.
It would be good if I could have done something like this though:
Dim s As New SubSonic.Select
s.From(VwPropertyList.Schema)
sWhere(VwPropertyList.Columns.IdCreatedBy).IsEqualTo(123)
sAnd(VwPropertyList.Columns.IdCounty).IsEqualTo(45)
s.And(29).In(New
InlineQuery("(SELECT Item FROM
SPLIT(DistrictGroupList, ','))"))

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