How am I print out the query.List()?
When I try to use Console.WriteLine(results) to get list.
It shows me like System.Collections.Generic.List`1[LocationSpecies.Domain.Location]
Am I going the right way?
using (ISession session = SessionHelper.OpenSession())
using (ITransaction trans = session.BeginTransaction())
{
Location location = session.Get<Location>(19596);
double elevation = location.Elevation;
Console.WriteLine(elevation);
// String hql = "From LocationSpecies.Domain.Location E where E.LocationId like '1%'";
var query = session.QueryOver<Location>()
.Where(r => r.Name == "Australia");
var results = query.List();
trans.Commit();
session.Close();
Console.WriteLine(results);
}
above query will return list() object.
So you can get the object by using foreach loop like follows
enter code here foreach(Location l : results){Console.writeline(l);}
Related
How do I run a raw query in ASP.NET core to return the row count from a table?
Currently, I am doing this and the returned result is -1. I think the return result is based on the number of records affected.
int numberOfRows = await
appDbContext.Database.ExecuteSqlInterpolatedAsync(
$"SELECT CODE FROM [samaster] WHERE CODE={productBrandCode} AND WAREHOUSE={warehouse} ");
Any idea on how to get the count back to numberOfRows variable will be appreciated.
NOTE: The above table is not a model so I need to run a raw query.
Thanks
It is currently not possible to get the query result when using ExecuteSqlInterpolatedAsync. The same applies to any additional LINQ Statements.
You can, however, use the underlying ADO.net Provider:
public IList<IDictionary<string, dynamic>> SelectDynamic(string table)
{
using (var command = Database.GetDbConnection().CreateCommand())
{
command.CommandText = $"SELECT * FROM [{table}]";
command.CommandType = CommandType.Text;
Database.OpenConnection();
using (var result = command.ExecuteReader())
{
var entities = new List<IDictionary<string, dynamic>>();
while (result.Read())
{
var dict = new Dictionary<string, dynamic>();
for (int i = 0; i < result.FieldCount; i++)
{
dict.Add(result.GetName(i), result.GetValue(i));
}
entities.Add(dict);
}
return entities;
}
}
}
Add this to your DbContext Class and Call it with:
using (var context = new MyDbContext()) // Or get it with DI, depends on your application
{
var count = context.SelectDynamic("samaster").Where(d => d["CODE"] == productBrandCode && d["WAREHOUSE"] == warehouse).Count();
}
Beware, however, that this is an expensive operation if you have a lot of rows in your table!
An alternative approach to only fetch the relevant results would be to replace
command.CommandText = $"SELECT * FROM [{table}]";
with
command.CommandText = $"SELECT CODE FROM [samaster] WHERE CODE={productBrandCode} AND WAREHOUSE={warehouse}";
and pass the parameters as function parameters.
public IList<IDictionary<string, dynamic>> SelectDynamic(string productBrandCode, string warehouse)
{...
Also make sure to escape all parameters if they are in any way submitted by user input to prevent SQL Injection Attacks!
There are two common approaches :
A.
int numberOfRows = await appDbContext.Database.ExecuteSqlInterpolatedAsync($"SELECT CODE FROM [samaster] WHERE CODE={productBrandCode} AND WAREHOUSE={warehouse} ").Count();
B.
int numberOfRows = await appDbContext.Database.ExecuteSqlInterpolatedAsync($"SELECT count(*) FROM [samaster] WHERE CODE={productBrandCode} AND WAREHOUSE={warehouse} ").First();
Since nobody gave me the correct answer. I end up using the following.
public async Task<bool> IsAValidProduct(string productBrandCode)
{
int count = 0;
await using DbCommand command = appDbContext.Database.GetDbConnection().CreateCommand();
command.CommandText =
"SELECT COUNT(CODE) FROM [samaster] WHERE CODE=#productBrandCode AND WAREHOUSE=#warehouse ";
command.CommandType = CommandType.Text;
command.Parameters.Add(new SqlParameter("#productBrandCode", SqlDbType.VarChar)
{Value = productBrandCode});
command.Parameters.Add(new SqlParameter("#warehouse", SqlDbType.VarChar)
{Value = warehouse});
await appDbContext.Database.OpenConnectionAsync();
count = (int) await command.ExecuteScalarAsync();
await appDbContext.Database.CloseConnectionAsync();
return count == 1;
}
int c= dbObj.Database.ExecuteSqlRaw(sql); //User this code
I have a C# .net application using the rally 3.0.1 API. When I query task in my system I get 0.0 for time spent when I know they have time against them. Anyone know how to get this? Below is my code:
if (uTasks.Count > 0)
{
Request taskRequest = new Request(resultChild["Tasks"]);
QueryResult TaskQueryResult = restApi.Query(taskRequest);
foreach (var items in TaskQueryResult.Results)
//foreach (var items in uTasks)
{
DataRow dtrow2;
dtrow2 = dt.NewRow();
dtrow2["TaskID"]=items["FormattedID"];
dtrow2["Task Name"] = items["Name"];
if (items["Owner"] != null)
{
var owner = items["Owner"];
String ownerref = owner["_ref"];
var ownerFetch = restApi.GetByReference(ownerref, "Name");
string strTemp = ownerFetch["_refObjectName"];
dtrow2["Owner"] = strTemp.Replace(",", " ");
}
\\else { dtrow2["Owner"] = ""; }
dtrow2["Task-Est"] = items["Estimate"];
dtrow2["Task-ToDo"] = items["ToDo"];
dtrow2["Task-Spent"] = items["TimeSpent"];
dtrow2["ObjectType"] = "T";
dt.Rows.Add(dtrow2);
}
}
It seems like that should work. You may want to make sure you're including the TimeSpent field in your fetch before issuing the request.
taskRequest.Fetch = new List<string>() { "TimeSpent" };
I am trying to execute the query (Basic select statement with 10 fields). My table contains more than 500k rows. C# application returns the response with only 4260 rows. However Web UI returns all the records.
Why my code returns only partial data, What is the best way to select all the records and load into C# Data Table? If there is any code snippet it would be more helpful to me.
using Google.Apis.Auth.OAuth2;
using System.IO;
using System.Threading;
using Google.Apis.Bigquery.v2;
using Google.Apis.Bigquery.v2.Data;
using System.Data;
using Google.Apis.Services;
using System;
using System.Security.Cryptography.X509Certificates;
namespace GoogleBigQuery
{
public class Class1
{
private static void Main()
{
try
{
Console.WriteLine("Start Time: {0}", DateTime.Now.ToString());
String serviceAccountEmail = "SERVICE ACCOUNT EMAIL";
var certificate = new X509Certificate2(#"KeyFile.p12", "notasecret", X509KeyStorageFlags.Exportable);
ServiceAccountCredential credential = new ServiceAccountCredential(
new ServiceAccountCredential.Initializer(serviceAccountEmail)
{
Scopes = new[] { BigqueryService.Scope.Bigquery, BigqueryService.Scope.BigqueryInsertdata, BigqueryService.Scope.CloudPlatform, BigqueryService.Scope.DevstorageFullControl }
}.FromCertificate(certificate));
BigqueryService Service = new BigqueryService(new BaseClientService.Initializer()
{
HttpClientInitializer = credential,
ApplicationName = "PROJECT NAME"
});
string query = "SELECT * FROM [publicdata:samples.shakespeare]";
JobsResource j = Service.Jobs;
QueryRequest qr = new QueryRequest();
string ProjectID = "PROJECT ID";
qr.Query = query;
qr.MaxResults = Int32.MaxValue;
qr.TimeoutMs = Int32.MaxValue;
DataTable DT = new DataTable();
int i = 0;
QueryResponse response = j.Query(qr, ProjectID).Execute();
string pageToken = null;
if (response.JobComplete == true)
{
if (response != null)
{
int colCount = response.Schema.Fields.Count;
if (DT == null)
DT = new DataTable();
if (DT.Columns.Count == 0)
{
foreach (var Column in response.Schema.Fields)
{
DT.Columns.Add(Column.Name);
}
}
pageToken = response.PageToken;
if (response.Rows != null)
{
foreach (TableRow row in response.Rows)
{
DataRow dr = DT.NewRow();
for (i = 0; i < colCount; i++)
{
dr[i] = row.F[i].V;
}
DT.Rows.Add(dr);
}
}
Console.WriteLine("No of Records are Readed: {0} # {1}", DT.Rows.Count.ToString(), DateTime.Now.ToString());
while (true)
{
int StartIndexForQuery = DT.Rows.Count;
Google.Apis.Bigquery.v2.JobsResource.GetQueryResultsRequest SubQR = Service.Jobs.GetQueryResults(response.JobReference.ProjectId, response.JobReference.JobId);
SubQR.StartIndex = (ulong)StartIndexForQuery;
//SubQR.MaxResults = Int32.MaxValue;
GetQueryResultsResponse QueryResultResponse = SubQR.Execute();
if (QueryResultResponse != null)
{
if (QueryResultResponse.Rows != null)
{
foreach (TableRow row in QueryResultResponse.Rows)
{
DataRow dr = DT.NewRow();
for (i = 0; i < colCount; i++)
{
dr[i] = row.F[i].V;
}
DT.Rows.Add(dr);
}
}
Console.WriteLine("No of Records are Readed: {0} # {1}", DT.Rows.Count.ToString(), DateTime.Now.ToString());
if (null == QueryResultResponse.PageToken)
{
break;
}
}
else
{
break;
}
}
}
else
{
Console.WriteLine("Response is null");
}
}
int TotalCount = 0;
if (DT != null && DT.Rows.Count > 0)
{
TotalCount = DT.Rows.Count;
}
else
{
TotalCount = 0;
}
Console.WriteLine("End Time: {0}", DateTime.Now.ToString());
Console.WriteLine("No. of records readed from google bigquery service: " + TotalCount.ToString());
}
catch (Exception e)
{
Console.WriteLine("Error Occurred: " + e.Message);
}
Console.ReadLine();
}
}
}
In this Sample Query get the results from public data set, In table contains 164656 rows but response returns 85000 rows only for the first time, then query again to get the second set of results. (But not known this is the only solution to get all the results).
In this sample contains only 4 fields, even-though it does not return all rows, in my case table contains more than 15 fields, I get response of ~4000 rows out of ~10k rows, I need to query again and again to get the remaining results for selecting 1000 rows takes time up to 2 minutes in my methodology so I am expecting best way to select all the records within single response.
Answer from User #:Pentium10
There is no way to run a query and select a large response in a single shot. You can either paginate the results, or if you can create a job to export to files, then use the files generated in your app. Exporting is free.
Step to run a large query and export results to files stored on GCS:
1) Set allowLargeResults to true in your job configuration. You must also specify a destination table with the allowLargeResults flag.
Example:
"configuration":
{
"query":
{
"allowLargeResults": true,
"query": "select uid from [project:dataset.table]"
"destinationTable": [project:dataset.table]
}
}
2) Now your data is in a destination table you set. You need to create a new job, and set the export property to be able to export the table to file(s). Exporting is free, but you need to have Google Cloud Storage activated to put the resulting files there.
3) In the end you download your large files from GCS.
It my turn to design the solution for better results.
Hoping this might help someone. One could retrieve next set of paginated result using PageToken. Here is the sample code for how to use PageToken. Although, I liked the idea of exporting for free. Here, I write rows to flat file but you could add them to your DataTable. Obviously, it is a bad idea to keep large DataTable in memory though.
public void ExecuteSQL(BigqueryService bqservice, String ProjectID)
{
string sSql = "SELECT r.Dealname, r.poolnumber, r.loanid FROM [MBS_Dataset.tblRemitData] R left join each [MBS_Dataset.tblOrigData] o on R.Dealname = o.Dealname and R.Poolnumber = o.Poolnumber and R.LoanID = o.LoanID Order by o.Dealname, o.poolnumber, o.loanid limit 100000";
QueryRequest _r = new QueryRequest();
_r.Query = sSql;
QueryResponse _qr = bqservice.Jobs.Query(_r, ProjectID).Execute();
string pageToken = null;
if (_qr.JobComplete != true)
{
//job not finished yet! expecting more data
while (true)
{
var resultReq = bqservice.Jobs.GetQueryResults(_qr.JobReference.ProjectId, _qr.JobReference.JobId);
resultReq.PageToken = pageToken;
var result = resultReq.Execute();
if (result.JobComplete == true)
{
WriteRows(result.Rows, result.Schema.Fields);
pageToken = result.PageToken;
if (pageToken == null)
break;
}
}
}
else
{
List<string> _fieldNames = _qr.Schema.Fields.ToList().Select(x => x.Name).ToList();
WriteRows(_qr.Rows, _qr.Schema.Fields);
}
}
The Web UI automatically flattens the data. This means that you see multiple rows for each nested field.
When you run the same query via the API, it won't be flattened, and you get fewer rows, as the nested fields are returned as objects. You should check if this is the case at you.
The other is that indeed you need to paginate through the results. Paging through list results has this explained.
If you want to do only one job, than you should write your query ouput to a table, than export the table as JSON, and download the export from GCS.
I'm trying to implement paging within my project.
When using NHibernate's IQueryOver syntax as shown below things are working as expected.
public PagedResult<T> ExecutePagedQuery(IQueryOver<T,T> query)
{
SetPaging(query);
var results = query.Future<T>();
var count = query.ToRowCountQuery().FutureValue<int>();
return new PagedResult<T>()
{
TotalItemCount = count.Value,
PageOfResults = results.ToList()
};
}
protected virtual void SetPaging(IQueryOver<T, T> query)
{
var maxResults = PageSize;
var numberToSkip = (PageNumber - 1) * PageSize;
query.Skip(numberToSkip).Take(maxResults);
}
For some queries we are using HQL instead of the IQueryOver syntax however.
I'm wondering if there is an equivalent to "query.ToRowCountQuery().FutureValue< int >()" that can be used when querying when passing an IQuery insead of an IQueryOver to provide the row count.
public PagedResult<T> ExecutePagedQuery(IQuery query)
{
SetPaging(query);
var results = query.Future<T>();
var count = // ToRowCountQueryEquivalent?
return new PagedResult<T>()
{
TotalItemCount = count,
PageOfResults = results.ToList()
};
}
protected virtual void SetPaging(IQuery query)
{
var maxResults = PageSize;
var numberToSkip = (PageNumber - 1) * PageSize;
query.SetFirstResult(numberToSkip);
query.SetMaxResults(maxResults);
}
some crazy idea
string countQuery;
if (query.QueryString.StartsWith("SELECT", StringComparison.OrdinalIgnoreCase))
countQuery = Regex.Replace(query.QueryString, "SELECT (.*) FROM", #"SELECT Count($1) FROM", RegexOptions.IgnoreCase);
else
countQuery = "SELECT COUNT(*) " + query.QueryString;
We've since converted our HQL queries to IQueryOver allowing us to take advantage of the ToRowCountQuery() helper.
I have a list of Ids and I want to get all the rows back in one query. As a list of objects(So a List of Products or whatever).
I tried
public List<TableA> MyMethod(List<string> keys)
{
var query = "SELECT * FROM TableA WHERE Keys IN (:keys)";
var a = session.CreateQuery(query).SetParameter("keys", keys).List();
return a; // a is a IList but not of TableA. So what do I do now?
}
but I can't figure out how to return it as a list of objects. Is this the right way?
List<TableA> result = session.CreateQuery(query)
.SetParameterList("keys", keys)
.List<TableA>();
Howeever there could be a limitation in this query if number of ":keys" exceed more than 1000 (incase of oracle not sure with other dbs) so i would recommend to use ICriteria instead of CreateQuery- native sqls.
Do something like this,
[TestFixture]
public class ThousandIdsNHibernateQuery
{
[Test]
public void TestThousandIdsNHibernateQuery()
{
//Keys contains 1000 ids not included here.
var keys = new List<decimal>();
using (ISession session = new Session())
{
var tableCirt = session.CreateCriteria(typeof(TableA));
if (keys.Count > 1000)
{
var listsList = new List<List<decimal>>();
//Get first 1000.
var first1000List = keys.GetRange(0, 1000);
//Split next keys into 1000 chuncks.
for (int i = 1000; i < keys.Count; i++)
{
if ((i + 1)%1000 == 0)
{
var newList = new List<decimal>();
newList.AddRange(keys.GetRange(i - 999, 1000));
listsList.Add(newList);
}
}
ICriterion firstExp = Expression.In("Key", first1000List);
ICriterion postExp = null;
foreach (var list in listsList)
{
postExp = Expression.In("Key", list);
tableCirt.Add(Expression.Or(firstExp, postExp));
firstExp = postExp;
}
tableCirt.Add(postExp);
}
else
{
tableCirt.Add(Expression.In("key", keys));
}
var results = tableCirt.List<TableA>();
}
}
}