The where clause in the LINQ statement below causes the following error when 'logLevel' has a value of "Error"
Error message = An error occurred while executing the command definition. See the inner exception for details.
Inner exception = p_linq_2 : String truncation: max=3, len=5, value='Error'
If I change && (logLevel == "All" || logLevel == "Error") to && (logLevel == "Error") the error no longer occurs.
It seems that to do the comparison against "All", LINQ tries to truncate the value in 'logLevel' to 3 characters first?
What is going on here?
(I'm running MVC 4, SQL CE 4)
IQueryable<LogEvent> list = (from a in _context.ELMAH_Error
where a.TimeUtc >= start && a.TimeUtc <= end
&& (logLevel == "All" || logLevel == "Error")
select new LogEvent
{
IdType = "guid", Id = "",IdAsInteger = 0,IdAsGuid = a.ErrorId,LoggerProviderName = "Elmah",LogDate = a.TimeUtc,MachineName = a.Host,Message = a.Message,Type = a.Type,Level = "Error",Source = a.Source,StackTrace = ""
});
Related
Terraform variable validation using length function
Getting error while using length function & substr for vswitch_ids
Condition - vswitch_name value must start with vsw-
variable "vswitch_ids" {
description = "The vswitch IDs."
type = list(string)
validation {
condition = (
length(var.vswitch_ids) > 0 &&
substr(var.switch_ids, 0, 4) == "vsw-"
)
error_message = "The vswitch_name value must start with \"vsw-\"."
}
}
Error: Invalid function argument
on modules/k8s/variables.tf line 34, in variable "vswitch_ids":
34: substr(var.vswitch_ids, 0, 4) == "vsw-"
|----------------
| var.vswitch_ids is list of string with 3 elements
Invalid value for "str" parameter: string required.
The following should work. It will check if all elements in your variable list start with vsw:
variable "vswitch_ids" {
description = "The vswitch IDs."
type = list(string)
validation {
condition = (
length(var.vswitch_ids) > 0 &&
length([for v in var.vswitch_ids: 1 if substr(v, 0, 4) == "vsw-"]) == length(var.vswitch_ids)
)
error_message = "The vswitch_name value must start with \"vsw-\"."
}
}
I am trying to order by start date(s.StartDate). Below is my code so far, my understanding is that I should be adding .orderby(s.StartDate) somewhere but I don't think I'm even taking the correct route now as I have tried many ways.
var query = from s in context.SessionSearch
where s.Children == 0 && s.IsPublic == isPublic
select s;
var query = from s in context.SessionSearch
where s.Children == 0 && s.IsPublic == isPublic
if (startDate != null)
{
query = query.Where(s => s.StartDate >= startDate && s.StartDate <= endDate);
}
You should be able to start with the "without startdate" option - you have a couple of options here - either declare the type of the query specifically:
IQueryable<SessionSearch> query = from s in context.SessionSearch
where s.Children == 0 && s.IsPublic == isPublic
order by s.StartDate
select s;
And then as you've tried, add the additional where clause to the query if there's a start date passed in:
query = query.Where(s => s.StartDate >= startDate && s.StartDate <= endDate);
This means that you would not be able to add further ordering via the ThenBy methods.
Alternatively, you can add the order by clause after you've finished adding the where clauses:
var query = from s in context.SessionSearch
where s.Children == 0 && s.IsPublic == isPublic
select s;
if (startDate != null) {
query = query.Where(s => s.StartDate >= startDate && s.StartDate <= endDate);
}
query = query.OrderBy(s => s.StartDate);
Props to JonSkeet for pointing these out.
the following query works ok if you comment out either the SinceID or the MaxID clause, but when both are included a "bad url" exception is generated.
var maxId = ulong.MaxValue;
var sinceId = (ulong)341350918903701507;
var searchResult =
(
from search in ctx.Search
where search.Type == SearchType.Search &&
search.ResultType == ResultType.Mixed &&
search.Query == "red wedding" &&
search.SinceID == sinceId &&
search.MaxID == maxId &&
search.IncludeEntities == false &&
search.Count == 200
select search).SingleOrDefault();
If you look at the query result in Fiddler, you'll see that the response is:
{"errors":[{"code":195,"message":"Missing or invalid url parameter"}]}
I can't respond to why Twitter wouldn't accept the query with both SinceID and MaxID. However, the query is formed correctly and there isn't any documentation describing constraints on the relationship between these two parameters for this particular scenario. The purpose of the MaxID is to be the id of the highest tweet to return on the next query. Both MaxID and SinceID are intended to help you page through data. I wrote a blog post on how to do this:
Working with Timelines with LINQ to Twitter
I seem to have the same problem as you are, so the only solution I have was to do it manually, so first I retrieved the the first list setting the sinceId value to the one I have like this:
var searchResult =
(
from search in TwitterCtx.Search
where search.Type == SearchType.Search &&
search.Query == query &&
search.Count == pageSize &&
search.IncludeEntities == true &&
search.ResultType == ResultType.Recent &&
search.SinceID == sinceId
select search
).SingleOrDefault<Search>();
resultList = searchResult.Statuses;
Then I have to search for other tweets (the case when new tweets count is more the pageSize) so I had a while loop like this:
ulong minId = ulong.Parse(resultList.Last<Status>().StatusID) - 1;
List<Status> newList = new List<Status>();
while (minId > sinceId)
{
resultList.AddRange(newList);
searchResult =
(
from search in TwitterCtx.Search
where search.Type == SearchType.Search &&
search.Query == query &&
search.Count == pageSize &&
search.IncludeEntities == true &&
search.ResultType == ResultType.Recent &&
search.MaxID == minId &&
search.SinceID == sinceId
select search
).SingleOrDefault<Search>();
newList = searchResult.Statuses;
if (newList.Count == 0)
break;
minId = ulong.Parse(newList.Last<Status>().StatusID) - 1;
}
Now for some reason here you can use both sinceId and maxId.
Just in case anyone else comes across this, I encountered this issue when the MaxId was an invalid Tweet Id.
I started off using zero but ulong.MaxValue has the same issue. Switch it out with a valid value and it works fine. If you're not using SinceId as well it seems to work fine.
I used to get same error "Missing or invalid url parameter", but as per Joe Mayo's solution, I have additionally added if(sinceID < maxID) condition before do while loop, because the query throws above error whenever maxID is less than sinceID, I think which is incorrect.
if (sinceID < maxID)
{
do
{
// now add sinceID and maxID
searchResponse =
await
(from search in twitterCtx.Search
where search.Type == SearchType.Search &&
search.Query == "from:#" + twitterAccountToDisplay + " -retweets" &&
search.Count == count &&
search.SinceID == sinceID &&
search.MaxID == maxID
select search)
.SingleOrDefaultAsync();
if (searchResponse == null)
break;
if (searchResponse.Count > 0 && searchResponse.Statuses.Count > 0)
{
newStatuses = searchResponse.Statuses;
// first tweet processed on current query
maxID = newStatuses.Min(status => status.StatusID) - 1;
statusList.AddRange(newStatuses);
lastStatusCount = newStatuses.Count;
}
if (searchResponse.Count > 0 && searchResponse.Statuses.Count == 0)
{
lastStatusCount = 0;
}
}
while (lastStatusCount != 0 && statusList.Count < maxStatuses);
//(searchResponse.Count != 0 && statusList.Count < 30);
}
How can I convert the following query in a Linq with Lambda ?
SELECT DISTINCT Registro, COUNT(Registro) as qnt
FROM XML_Relatorio
WHERE Arquivo = 'redenet.xml'
AND TipoErro <> 'Imovel Inserido'
AND TipoErro <> 'TI'
AND DataHora BETWEEN '01-01-2012' AND '02-01-2012'
GROUP BY Registro
ORDER BY Registro
I'm trying the following code, but I need some help to build the LINQ with Lambda
IQueryable<XML_Relatorio> quantidadeErro = db.XML_Relatorios
.Where(a => a.Arquivo == "redenet.xml"
&& a.TipoErro != "Imovel Inserido"
&& a.TipoErro != "TI");
Supposing the DataHora field is of Date or DateTime type.
// parse the strings to datetime
var start = DateTime.Parse("01-01-2012");
var end = DateTime.Parse("02-01-2012");
IQueryable<XML_Relatorio> quantidadeErro = db.XML_Relatorios
.Where(a => a.Arquivo == "redenet.xml"
&& a.TipoErro != "Imovel Inserido"
&& a.TipoErro != "TI"
// and compare them...
&& a.DataHora > start && a.DataHora < end);
I want to generate dynamic query to check manage the where clause with number of parameters available...if some parameter is null i don't want to include it in the where clause
var test = from p in _db.test
where if(str1 != null){p.test == str} else i dnt wanna check p.test
I have around 14 parameters for the where clause
need help,
thanks
You can do it in steps:
// set up the "main query"
var test = from p in _db.test select _db.test;
// if str1 is not null, add a where-condition
if(str1 != null)
{
test = test.Where(p => p.test == str);
}
In addition to #Fredrik's answer, you can also use the short-circuit rules when evaluating boolean expressions like so:
var test = from p in _db.test
where str1 == null || p.test == str1;
Edit If you have lots of strings to test, (str1, str2, etc...) then you can use the following, which will be translated to an SQL IN clause:
var strings = new List<string>();
if (str1 != null) strings.Add(str1);
if (str2 != null) strings.Add(str2);
if (str3 != null) strings.Add(str3);
...
var test = from p in _db.test
where strings.Contains(p.test);
It's even easier if your strings are already in a collection (which, if you've got 14 of them, I assume they would be...)
Consider param1 and param2 are the parameters. Your query should be as under:
string param1 = "Value1";
string param2 = "Value2";
var q = from bal in context.FxBalanceDetails
where (string.IsNullOrEmpty(param1) || bal.Column1 == param1)
&& (string.IsNullOrEmpty(param2) || bal.Column2 == param2)
select bal;
This will ensure that the where clause gets applied for the particular parameter only when it is not null.
var test =
from p in _db.test
where p.str1 != null ? p.str1 : ""
select p;
Do you check the strings against the same Field of the entity?
If so you can write something like:
var strings = new[] { "foo", "bar", "ok", "", null };
var query = dataContext.YourTable.AsQueryable();
query = strings.Where(s => !string.IsNullOrEmpty(s))
.ToList()
.Aggregate(query, (q, s) => q.Where(e => e.YourField == s));
EDIT:
The previous solution is overcomplicated:
var strings = new[] { "foo", "bar", "ok", "", null }.Where(s => !string.IsNullOrEmpty(s))
.ToList();
var query = dataContext.YourTable.Where(e => strings.Contains(e.YourField));