I need to get the maximum value from table that should belongs to particular category.
My code as follows :
private int getHighScores(int _playMode)
{
int maxScore = 0;
using (HangmanScoreDataContext hangmanDB = new HangmanScoreDataContext(#"isostore:/HangmanScoreDB.sdf"))
{
IQueryable<TbleHangmanScore> sqlQuery = hangmanDB._tbleHangman;
sqlQuery = sqlQuery.Where(p => p.playMode == _playMode);
maxScore = sqlQuery.AsQueryable().Max(p => p.score);
}
return maxScore;
}
I am getting error like
an unhandled exception of type 'system.stackoverflowexception' occurred in unknown module.
Except maximum value rest of the things working properly . How can i solve this issue ?
Edit : Problem arises only when the table contains zero numbers of records. Same problem when i trying to get the minimum value also.
Related
I am getting following exception on windows while running the below
ERROR: operator does not exist: numeric = character varying Hint: No operator matches the given name and argument type(s). You might need to add explicit type casts." while executing with query parameter
I am passing the Numeric String for parameter using function as a named parameter to the query
getUIDCount(String id) {
...
select count(UID) as icrd FROM UID_tbl WHERE id = ?
...
}
where id is numeric(5,0)" in table
Everything works well on Ubuntu but getting Error while running the same code on windows. I have to do the explicit casting just for windows. I am using PostgreSQL 9.4.3. I am using "org.hibernate.dialect.PostgreSQLDialec" and grails 2.3.11 with runtime 'org.postgresql:postgresql:9.3-1100-jdbc41'
updated with how it is getting called
def Integer getUIDSetSize(String _id)
{
Integer i = 0;
Sql sql = new Sql(dataSource);
String sqlt = """select count(UID) as icrd FROM UID_tbl WHERE _id = ?""";
log.trace(sqlt);
sql.eachRow(sqlt, [_id], { row -> i = row.icrd; });
return i;
}
This how it get called def _id1 = params._id1; count1 = HelperService.getUIDSetSize(_id1)
The workaround for casting from varchar to numeric is
CREATE CAST(VARCHAR AS NUMERIC) WITH INOUT AS IMPLICIT;
This is not the best solution and would suggest selective casting from the code.
We are interested in the statistics of the different pages combined from the Google Analytics core reporting API. The only way I found to query statistics multiple pages at the same is by creating a filter like so:
ga:pagePath==page?id=a,ga:pagePath==page?id=b,ga:pagePath==page?id=c
And this get escaped inside the filter parameter of the GET query.
However when the GET query gets over 2000 characters I get the following response:
414. That’s an error.
The requested URL /analytics/v3/data/ga... is too large to process. That’s all we know.
Note that just like in the example call the only part that is different per page is a GET parameter in the pagePath, but we have to OR a new filter specifying both the metric (pagePath) as well as the part of the path that is always identical.
Is there any way to specify a large number of different pages to query without hitting this limit in the GET query (I can't find any documentation for doing POST requests)? Or are there alternatives to creating batches of a max of X different pages per query and adding them up on my end?
Instead of using ga:pagePath as part of a filter you should use it as a dimension. You can get up to 10,000 rows per query this way and paginate to get all results. Then parse the results client side to get what you need. Additionally use a filter to scope the results down if possible based on your site structure or page names.
I am sharing a sample code where you can fetch more then 10,000 record data via help of Items PerPage
private void GetDataofPpcInfo(DateTime dtStartDate, DateTime dtEndDate, AnalyticsService gas, List<PpcReportData> lstPpcReportData, string strProfileID)
{
int intStartIndex = 1;
int intIndexCnt = 0;
int intMaxRecords = 10000;
var metrics = "ga:impressions,ga:adClicks,ga:adCost,ga:goalCompletionsAll,ga:CPC,ga:visits";
var r = gas.Data.Ga.Get("ga:" + strProfileID, dtStartDate.ToString("yyyy-MM-dd"), dtEndDate.ToString("yyyy-MM-dd"),
metrics);
r.Dimensions = "ga:campaign,ga:keyword,ga:adGroup,ga:source,ga:isMobile,ga:date";
r.MaxResults = 10000;
r.Filters = "ga:medium==cpc;ga:campaign!=(not set)";
while (true)
{
r.StartIndex = intStartIndex;
var dimensionOneData = r.Fetch();
dimensionOneData.ItemsPerPage = intMaxRecords;
if (dimensionOneData != null && dimensionOneData.Rows != null)
{
var enUS = new CultureInfo("en-US");
intIndexCnt++;
foreach (var lstFirst in dimensionOneData.Rows)
{
var objPPCReportData = new PpcReportData();
objPPCReportData.Campaign = lstFirst[dimensionOneData.ColumnHeaders.IndexOf(dimensionOneData.ColumnHeaders.FirstOrDefault(h => h.Name == "ga:campaign"))];
objPPCReportData.Keywords = lstFirst[dimensionOneData.ColumnHeaders.IndexOf(dimensionOneData.ColumnHeaders.FirstOrDefault(h => h.Name == "ga:keyword"))];
lstPpcReportData.Add(objPPCReportData);
}
intStartIndex = intIndexCnt * intMaxRecords + 1;
}
else break;
}
}
Only one thing is problamatic that your query length shouldn't exceed around 2000 odd characters
I have seen some questions related to this Exception here but none made me understand the root cause of the problem. So here we have one more...
var testquery =
((from le in context.LoanEMIs.Include("LoanPmnt")
join lp in context.LoanPmnts on le.Id equals lp.LoanEMIId
where lp.PmntDtTm < date && lp.IsPaid == false
&& le.IsActive == true && lp.Amount > 0
select new ObjGetAllPendingPmntDetails
{
Id = lp.Id,
Table = "LoanEMI",
loanEMIId = lp.LoanEMIId,
Name = le.AcHead,
Ref = SqlFunctions.StringConvert((double)le.FreqId),
PmntDtTm = lp.PmntDtTm,
Amount = lp.Amount,
IsDiscard = lp.IsDiscarded,
DiscardRemarks = lp.DiscardRemarks
}).DefaultIfEmpty(ObjNull));
List<ObjGetAllPendingPmntDetails> test = testquery.ToList();
This query gives the following Exception Message -
Unable to create a constant value of type CashVitae.ObjGetAllPendingPmntDetails. Only primitive types or enumeration types are supported in this context.
I got this Exception after I added the SQL function statement to convert le.FreqId which is a byte to a string as ToString() is not recognized in the LINQ Expression Store.
ObjGetAllPendingPmntDetails is a partial class in my model which is added as it is used too many times in the code to bind data to tables.
It has both IDs as long, 'Amount' as decimal, PmntDtTm as Datetime,IsDiscard as bool and remaining all are string including 'Ref'.
I get no results as currently no data satisfies the condition. While trying to handle null, I added DefaultIfEmpty(ObjNull) and ObjNull has all properties initialized as follows.
ObjGetAllPendingPmntDetails ObjNull = new ObjGetAllPendingPmntDetails()
{ Id = 0, Table = "-", loanEMIId = 0, Name = "-", Ref = "-",
PmntDtTm = Convert.ToDateTime("01-01-1900"),
Amount = 0, IsDiscard = false, DiscardRemarks = "" };
I need this query to work fine as it has Union() called on it with 5 other queries. All returning the same ObjGetAllPendingPmntDetails columns. But there is some problem as this query has no data satisfying the conditions and the Exception Shared Above.
Any suggestions are appreciated as I am unable to understand the root cause of the problem.
#AndrewCoonce is right, the .DefaultIfEmpty(ObjNull) is the culprit here. Entity Framework turns DefaultIfEmpty into something like...
CASE WHEN ([Project1].[C1] IS NULL) THEN #param ELSE [Project1].[Value] END AS [C1]
...but there's no way to coerce an instance of ObjGetAllPendingPmntDetails into something that can take the place of #param, so you get an exception.
If you move the DefaultIfEmpty call to after the ToList it should work correctly (although you'll need to call ToList again after that if you really want a concrete list instance).
I have the following code
nodes = data.Descendants(XName.Get("{http://schemas.microsoft.com/LiveSearch/2008/04/XML/web}Results")).Nodes();
System.Collections.Generic.IEnumerable<Result> res = new List<Result>();
if (nodes.Count() > 0)
{
var results = from uris in nodes
select new Result
{
URL =
((XElement)uris).Element(XName.Get("{http://schemas.microsoft.com/LiveSearch/2008/04/XML/web}Url")).Value,
Title =
((XElement)uris).Element(XName.Get("{http://schemas.microsoft.com/LiveSearch/2008/04/XML/web}Title")).Value,
Description =
((XElement)uris).Element(XName.Get("{http://schemas.microsoft.com/LiveSearch/2008/04/XML/web}Description")).Value,
DateTime =
((XElement)uris).Element(XName.Get("{http://schemas.microsoft.com/LiveSearch/2008/04/XML/web}DateTime")).Value,
};
res = results;
}
Where Results is a object who has those URL, Title, Description, and DateTime variables defined.
This all works fine normally, but when a 'node' in nodes doesnt contain a Description element (or at least I think thats whats throwing it) the program hits the "res = results;"
line of code and throws a 'object reference not set to...' error and highlights the whole section right after "select new Results"..
How do I fix this?
The simplest way is to cast to string instead of using the Value property. That way you'll end up with a null reference for the Description instead.
However, your code can also be made a lot nicer:
XNamespace ns = "http://schemas.microsoft.com/LiveSearch/2008/04/XML/web";
var results = data.Descendants(ns + "Results")
.Elements()
.Select(x => new Result
{
URL = (string) x.Element(ns + "Url"),
Title = (string) x.Element(ns + "Title"),
Description = (string) x.Element(ns + "Description"),
DateTime = (string) x.Element(ns + "DateTime")
})
.ToList();
See how much simpler that is? Techiques used:
Calling ToList() on an empty sequence gives you a list anyway
This way you'll only ever perform the query once; before you were calling Count() which would potentially have iterated over each node. In general, use Any() instead of Count() > 0) - but this time just making the list unconditional is simpler.
Use the Elements() method to get child elements, rather than casting multiple times. (Your previous code would have thrown an exception if it had encountered any non-element nodes)
Use the implicit conversion from string to XNamespace
Use the +(XNamespace, string) operator to get an XName
If the Description element is not included you should test if this
((XElement)uris).Element(XName.Get("{http://schemas.microsoft.com/LiveSearch/2008/04/XML/web}Description"))
is not null before using Value. Try this code:
var results = from uris in nodes let des = ((XElement)uris).Element(XName.Get("{http://schemas.microsoft.com/LiveSearch/2008/04/XML/web}Description"))
select new Result
{
URL = ((XElement)uris).Element(XName.Get("{http://schemas.microsoft.com/LiveSearch/2008/04/XML/web}Url")).Value,
Title = ((XElement)uris).Element(XName.Get("{http://schemas.microsoft.com/LiveSearch/2008/04/XML/web}Title")).Value,
Description = (des != null) ? des.Value : string.Empty,
DateTime = ((XElement)uris).Element(XName.Get("{http://schemas.microsoft.com/LiveSearch/2008/04/XML/web}DateTime")).Value,
};
I have met a problem about inserting multiple rows in a batch with Subsonic3. My development environment includes:
1. Visual Studio 2010, but use .NET 3.5
2. Active Record Mode in SubSonic 3.0.0.4
3. SQL Server 2005 express
4. Northwind sample database
I am using Active Reecord mode to insert mutiple "Product" into table "Products". If I insert the rows one by one, either call "aProduct.Add()" or call "Insert.Execute()" mutiple times (just like the codes below), it works fine.
private static Product[] CreateProducts(int count)
{
Product[] products = new Product[count];
for (int index = 0; index < products.Length; ++index)
{
products[index] = new Product
{
ProductName = string.Format("cheka-test-{0}", index.ToString()),
Discontinued = (index % 2 == 0),
};
}
return products;
}
private static void SucceedByMultiExecuteInsert()
{
Product[] products = CreateProducts(2);
// -------------------------------- prepare batch
NorthwindDB db = new NorthwindDB();
var inserts = from prod in products
select db.Insert.Into<Product>(x => x.ProductName, x => x.Discontinued).Values(prod.ProductName, prod.Discontinued);
// -------------------------------- batch insert
var selectAll = Product.All();
Console.WriteLine("--- before total rows = {0}", selectAll.Count().ToString());
foreach (Insert insert in inserts)
insert.Execute();
Console.WriteLine("+++ after inserting {0} rows, now total rows = {1}",
products.Length.ToString(), selectAll.Count().ToString());
}
but if I use "BatchQuery" like the codes below,
private static void FailByBatchInsert()
{
Product[] products = CreateProducts(2);
// -------------------------------- prepare batch
NorthwindDB db = new NorthwindDB();
BatchQuery batchquery = new BatchQuery(db.Provider, db.QueryProvider);
var inserts = from prod in products
select db.Insert.Into<Product>(x => x.ProductName, x => x.Discontinued).Values(prod.ProductName, prod.Discontinued);
foreach (Insert insert in inserts)
batchquery.Queue(insert);
// -------------------------------- batch insert
var selectAll = Product.All();
Console.WriteLine("--- before total rows = {0}", selectAll.Count().ToString());
batchquery.Execute();
Console.WriteLine("+++ after inserting {0} rows, now total rows = {1}",
products.Length.ToString(), selectAll.Count().ToString());
}
then it failed with the exception :
"
Unhandled Exception: System.Data.SqlClient.SqlException: Must declare the scalar variable "#ins_ProductName".
Must declare the scalar variable "#ins_ProductName".
"
Please give me some help to solve this problem. Many thanks.
I ran into this problem as well. If you look at the query it's attempting to run, you'll see it doing something like this (this isn't actual code but you'll get the point):
exec_sql N'insert into MyTable (SomeField) Values (#ins_SomeField)',N'#0 varchar(32)','#0=SomeValue'
For some reason it defines the parameters in the query with "#ins_"+FieldName but then passes the parameters as ordinals. I have yet to determine the pattern for why/when it does this but I've lost enough time during this dev cycle futzing with SubSonic to try and diagnose the problem properly.
The work-around I implemented will involve you downloading the 3.0.0.4 source from github and making a change on line 179 of Insert.cs.
Where it reads
ParameterName = _provider.ParameterPrefix + "ins_" + columnName.ToAlphaNumericOnly(),
Changing it to
ParameterName = _provider.ParameterPrefix + Inserts.Count.ToString(),
seemed to do the trick for me. I make no warranties about this solution for you, expressed or implied. It did work for me but your mileage may vary.
I should also note that there's similar logic around the "update" statements as well in Update.cs on lines 181 and 194 but I haven't had these give me problems... yet.
Honestly, I don't think SubSonic is ready for primetime and that's a shame because I really like how Rob set it up. That said, it's in my product for better or worse now so you make the best with what you got.