I'm having issues implementing the TOP or SKIP functionality when building a new object query.
I can't use eSQL because i need to use an "IN" command - which could get quite complex if I loop over the IN and add them all as "OR" parameters.
Code is below :
Using dbcontext As New DB
Dim r As New ObjectQuery(Of recipient)("recipients", dbcontext)
r.Include("jobs")
r.Include("applications")
r = r.Where(Function(w) searchAppIds.Contains(w.job.application_id))
If Not statuses.Count = 0 Then
r = r.Where(Function(w) statuses.Contains(w.status))
End If
If Not dtFrom.DbSelectedDate Is Nothing Then
r = r.Where(Function(w) w.job.create_time >= dtDocFrom.DbSelectedDate)
End If
If Not dtTo.DbSelectedDate Is Nothing Then
r = r.Where(Function(w) w.job.create_time <= dtDocTo.DbSelectedDate)
End If
'a lot more IF conditions to add in additional predicates
grdResults.DataSource = r
grdResults.DataBind()
If I use any form of .Top or .Skip it throws an error : Query builder methods are not supported for LINQ to Entities queries
Is there any way to specify TOP or Limit using this method? I'd like to avoid a query returning 1000's of records if possible. (it's for a user search screen)
Rather than
r = new ObjectQuery<recipient>("recipients", dbContext)
try
r = dbContext.recipients.
.Skip() and .Take() return IOrderedQueriable<T> while .Where returns IQueriable<T>. Thus put the .Skip() and .Take() last.
Also change grdResults.DataSource = r to grdResults.DataSource = r.ToList() to execute the query now. That'll also allow you to temporarily wrap this line in try/catch, which may expose a better message about why it's erroring.
Mark this one down to confusion. I should have been using the .Take instead of .Top or .Limit or anything.
my final part is the below and it works :
grdResults = r.Take(100)
Related
Is it possible to perform a dynamic "where/filter" in a dataframe ?
I am running a "like" operation to remove items that match specific strings
eventsDF.where(
~eventsDF.myColumn.like('FirstString%') &
~eventsDF.myColumn.like('anotherString%')
).count()
However I need to filter based on strings that come from another dataframe/list.
The solution that I was going for (which doesn't really work) involves a function that receives an index
#my_func[0] = "FirstString"
#my_func[1] = "anotherString"
def my_func(n):
return str(item[n])
newDf.where(
~newDf.useragent.like(str(my_func(1))+'%')
).count()
but I'm struggling to make it work by passing a range (mainly because it's a list instead of an integer)
newDf.where(
~newDf.useragent.like(str(my_func([i for i in range(2)])+'%'))
).count()
I don't want to go down the path of using "exec" or "eval" to perform it
str_likes = [~df.column.like(s) for s in strings] then reduce it into one expression reduce(lambda x, y: x & y, str_likes)
It's a little bit ugly but does what you want. You can also do this in a for loop like so
bool_expr = ~df.column.like(strings[0])
for s in strings[1:]:
bool_expr &= ~df.column.like(s)
df.where(bool_expr).count()
Currently i have two gremlin queries which will fetch two different values and i am populating in a map.
Scenario : A->B , A->C , A->D
My queries below,
graph.V().has(ID,A).out().label().toList()
Fetch the list of outE labels of A .
Result : List(B,C,D)
graph.traversal().V().has("ID",A).outE("interference").as("x").otherV().has("ID",B).select("x").values("value").headOption()
Given A and B , get the egde property value (A->B)
Return : 10
Is it possible that i can combine both there queries to get a return as Map[(B,10)(C,11)(D,12)]
I am facing some performance issue when i have two queries. Its taking more time
There is probably a better way to do this but I managed to get something with the following traversal:
gremlin> graph.traversal().V().has("ID","A").outE("interference").as("x").otherV().has("ID").label().as("y").select("x").by("value").as("z").select("y", "z").select(values);
==>[B,1]
==>[C,2]
I would wait for more answers though as I suspect there is a better traversal out there.
Below is working in scala
val b = StepLabel[Edge]()
val y = StepLabel[Label]()
val z = StepLabel[Integer]()
graph.traversal().V().has("ID",A).outE("interference").as(b)
.otherV().label().as(y)
.select(b).values("name").as(z)
.select((y,z)).toMap[String,Integer]
This will return Map[String,Int]
Can any one tell how to add roll up functionality in sugarCRM(Ce).
Our requirement is to "sum of project amounts to roll up to opportunity amount field in sugar crm"
You can achieve it by writing after_save logic hook as described below:
I have achived similar functionality where sum of pending amount of each cases will be store in accounts module.
$customer_id = $_REQUEST['mc_companyusers_cases_1mc_companyusers_ida'];
if($customer_id){
$rs = $bean->db->query("SELECT cc.pending_payment_c FROM mc_companyusers_cases_1_c m inner join cases c on m.`mc_companyusers_cases_1cases_idb` = c.`id` inner join cases_cstm cc on cc.`id_c` = c.`id` where m.`mc_companyusers_cases_1mc_companyusers_ida` = '".$customer_id."'");
$total_pending_amount = 0;
while($row = $bean->db->fetchByAssoc($rs)){
$total_pending_amount += $row['pending_payment_c'];
}
$bean->db->query("Update mc_companyusers_cstm set total_pending_payment_c='".$total_pending_amount."' where id_c='".$customer_id."'");
}
So you can map project module with cases and opportunity module with account in above query.
Thank you.
You could add a field with a function that dynamically calculates the sum.
Or use a logic hook that adds to a real db field whenever a submodule item gets added.
This sort of thing:
Dim MatchingValues() As Integer = {5, 6, 7}
Return From e in context.entity
Where MatchingValues.Contains(e.Id)
...works great. However, in my case, the values in MatchingValues are provided by the user. If none are provided, all rows ought to be returned. It would be wonderful if I could do this:
Return From e in context.entity
Where (MatchingValues.Length = 0) OrElse (MatchingValues.Contains(e.Id))
Alas, the array length test cannot be converted to SQL. I could, of course, code this:
If MatchingValues.Length = 0 Then
Return From e in context.entity
Else
Return From e in context.entity
Where MatchingValues.Contains(e.Id)
End If
This solution doesn't scale well. My application needs to work with 5 such lists, which means I'd need to code 32 queries, one for every situation.
I could also fill MatchingValues with every existing value when the user doesn't want to use the filter. However, there could be thousands of values in each of the five lists. Again, that's not optimal.
There must be a better way. Ideas?
Give this a try: (Sorry for the C# code, but you get the idea)
IQueryable<T> query = context.Entity;
if (matchingValues.Length < 0) {
query = query.Where(e => matchingValues.Contains(e.Id));
}
You could do this with the other lists aswell.
With Linq to Entities, I am trying to query a Log table to find rows near a matching row. I am having trouble with adding a date inside the query. This is what I have so far.
from
l in objectSet.Logs
let
match = objectSet.Logs.Where(whatever).FirstOrDefault()
where
l.Timestamp > (match.Timestamp - twoHours)
&& l.Timestamp < (match.Timestamp + twoHours)
select
l
Leaving out the "whatever" condition that finds the row I'm interested in, "twoHours" has variably been a time span, a .AddHours() function and so forth. I haven't found the right way that EF can generate SQL that adds the value from a field (match.Timestamp) to a constant.
The obvious solution is to do the "match" query first and then use the literal value in a second query, but I have simplified the code example here to the main problem (adding dates in the query) and in actual fact my query is more complex and this would not be ideal.
Cheers
You can generate an AddHours using the EntityFunctions class.
from
l in objectSet.Logs
let
match = objectSet.Logs.Where(whatever).FirstOrDefault()
where
(l.Timestamp > EntityFunctions.AddHours(match.Timestamp, -1 * twoHours))
&& // ...
select
l
However, don't expect this WHERE to be optimized with an index unless you have an expression index on the column.
EntityFunctions is deprecated in favor of DbFunctions
public int GetNumUsersByDay(DateTime Date)
{
using (var context = db)
{
var DateDay = new DateTime(Date.Year, Date.Month, Date.Day);
var DateDayTomorrow = DateDay.AddDays(1);
return context.Users.Where(m => DbFunctions.AddHours(m.DateCreated,-5) >= DateDay && m.DateCreated < DateDayTomorrow).Count();
}
}
As it was described in this article - http://www.devart.com/blogs/dotconnect/?p=2982#first, use parameters (declare variable) instead of DateTime using in your queries.