I have a query using Npgsql and Postgres. For building my query I am using Dapper and its SqlBuilder.
When I make the normal statement in the DB it is returning the correct result. When I am doing it via the SqlBuilder it is returning the wrong result.
I tried different way, changed the addTemplate or the parameters, but it changed nothing.
Also I have tried to change the line builder.Where("period = #period", new { model.Period }); in different ways:
builder.Where("period = #Period", new { model.Period });
builder.Where("period = period", new { model.Period });
builder.Where("period = #TestPeriod", new { TestPeriod = model.Period });
Or is this a more common way:
builder.Where("period = '" + model.Period + "'");
using (NpgsqlConnection con = Helper.GetNpgsqlConnection())
{
var builder = new SqlBuilder();
var selector = builder.AddTemplate("SELECT * FROM szzRecord.folders /**where**/");
if (model.Period != null)
builder.Where("period = #period", new { model.Period });
var result = con.Query(selector.RawSql);
return result;
}
The result with the normal sql query for example: SELECT * FROM szzRecord.folders WHERE period = 24 is returning 251 rows - which is correct.
The result with the dapper query is 1223, which are all rows. So it kinda looks that the parameter doesn't exist. On expecting the selector I find my parameter for period. I found Period = 24 inselector.parameters.templates[0]. Is this correct? selector.parameters.parameters is empty.
You need to pass the SqlBuilder's parameters into your query. You have:
var result = con.Query(selector.RawSql);
Change this to:
var result = con.Query(selector.RawSql, selector.Parameters);
Related
I am using the following helper function:
public List<EventRecord> GetEvents(DateTime afterTime)
{
var formattedDateTime = $"{afterTime:yyyy-MM-dd}T{afterTime:HH:mm:ss}.000000000Z";
var query = $"*[(System/Provider/#Name='.Net Runtime') and (System/EventID=1000) and (System/TimeCreated/#SystemTime >= '{formattedDateTime}')]";
var queryResult = new EventLogQuery("Application", PathType.LogName, query);
var reader = new EventLogReader(queryResult);
var events = new List<EventRecord>();
while (true)
{
var rec = reader.ReadEvent();
if (rec == null)
{
break;
}
events.Add(rec);
}
return events;
}
This code almost works except the query seems to be ignoring the TimeCreated entirely. It's returning all events with the given ProviderName and EventId. I have tried all sorts of different things to get this to work but no matter what, TimeCreated is ignored.
Anyone see what I'm doing wrong?
Edit 1
Even replacing the query line with:
var query = $"*[System[TimeCreated[#SystemTime >= '{formattedDateTime}']]]";
Doesn't work. Returns all events regardless of when they were Created.
Edit 2
So I tried using the 'custom view' builder to generate an XML query for me and what I found was even more perplexing:
So currently the time displayed on my machine is: 2:42pm.
In 24 hour time it should be 14:42pm.
When I create a query using the custom view and select:
From: 'Events On' 03/18/2021 2:42pm , it creates the following:
<QueryList>
<Query Id="0" Path="Application">
<Select Path="Application">*[System[Provider[#Name='.NET Runtime'] and (EventID=1000) and TimeCreated[#SystemTime>='2021-03-18T20:42:13.000Z']]] </Select>
</Query>
</QueryList>
Why on gods green earth did it convert 2:42pm to 20:42?
So apparently you need to convert your time to UniversalTime for this to work.
Here is a working sample:
public List<EventRecord> GetEvents(DateTime afterTime)
{
var formattedDateTime = afterTime.ToUniversalTime().ToString("o");
var query = $"*[System[Provider[#Name='.NET Runtime'] and (EventID=1000) and TimeCreated[#SystemTime>='{formattedDateTime}']]]";
var queryResult = new EventLogQuery("Application", PathType.LogName, query);
var reader = new EventLogReader(queryResult);
var events = new List<EventRecord>();
while (true)
{
var rec = reader.ReadEvent();
if (rec == null)
{
break;
}
events.Add(rec);
}
return events;
}
In Cosmos DB I can use Json fragments as part of a where clause for a query such that
SELECT * FROM c WHERE c.path.to.propery={"where":{"value":{"is":true}}}
yields results (of course if there are any)
now I want to use the same idea when querying using SqlParamters
var stmt = new SqlQuerySpec
{
QueryText = "SELECT * FROM c WHERE c.path.to.propery=#myjson",
Parameters = new SqlParameterCollection()
{
new SqlParameter{ Name = "#myjson", Value = ??? }
}
};
Any idea what (if any at all) needs to go instead of the ??? to have the json fragment {"where":{"value":{"is":true}}} in the query
Edit
Simply adding a string as a param value will not work as strings correctly will be enclosed in " to prevent SQL injection attacks.
using an anonymous object like
myjson = new { where = new { value = new { #is = true } } }
might work (I havent tried it out) but wont work in my specif case as the JSON and its structure are unknown at compile time.
I found the solution in the form of cosmos DBs StringToObject function so that
var myjson = #"{""where"":{""value"":{""is"":true}}}"
var stmt = new SqlQuerySpec
{
QueryText = "SELECT * FROM c WHERE c.path.to.propery=StringToObject(#myjson)",
Parameters = new SqlParameterCollection()
{
new SqlParameter{ Name = "#myjson", Value = myjson }
}
};
I have a query somewhat like the following which I'm trying to parameterize:
List<string> poiIDs = /*List of poi ids*/;
List<string> parameterNames = /*List of parameter names*/;
string inClause = string.Join(",", parameterNames);
string query = string.Format("SELECT c.id AS poiID, c.poiName, c.latitude, c.longitude FROM c WHERE c.clusterName = #clusterName AND c.id IN ({0}) AND c.deleted = false", inClause);
IQueryable<POI> queryResult = Client.CreateDocumentQuery<POI>(Collection.SelfLink, new SqlQuerySpec
{
QueryText = query,
Parameters = new SqlParameterCollection()
{
new SqlParameter("#clusterName", "POI"),
// How do I declare the dynamically generated parameters here
// as new SqlParameter()?
}
});
How do I declare the dynamically generated parameters as new SqlParameter() for the Parameters property of SqlQuerySpec in order to create my document query?
You can create dynamic parameterized query like this:
// DocumentDB query
// POINT TO PONDER: create the formatted query, so that after creating the dynamic query we'll replace it with dynamically created "SQL Parameter/s"
var queryText = #"SELECT
us.id,
us.email,
us.status,
us.role
FROM user us
WHERE us.status = #userStatus AND us.email IN ({0})";
// contain's list of emails
IList<string> emailIds = new List<string>();
emailIds.Add("a#gmail.com");
emailIds.Add("b#gmail.com");
#region Prepare the query
// simple parameter: e.g. check the user status
var userStatus = "active";
var sqlParameterCollection = new SqlParameterCollection { new SqlParameter("#userStatus", userStatus) };
// IN clause: with list of parameters:
// first: use a list (or array) of string, to keep the names of parameter
// second: loop through the list of input parameters ()
var namedParameters = new List<string>();
var loopIndex = 0;
foreach (var email in emailIds)
{
var paramName = "#namedParam_" + loopIndex;
namedParameters.Add(paramName);
var newSqlParamter = new SqlParameter(paramName, email);
sqlParameterCollection.Add(newSqlParamter);
loopIndex++;
}
// now format the query, pass the list of parameter into that
if (namedParameters.Count > 0)
queryText = string.Format(queryText, string.Join(" , ", namedParameters));
// after this step your query is something like this
// SELECT
// us.id,
// us.email,
// us.status,
// us.role
// FROM user us
// WHERE us.status = #userStatus AND us.email IN (#namedParam_0, #namedParam_1, #namedParam_2)
#endregion //Prepare the query
// now inject the parameter collection object & query
var users = Client.CreateDocumentQuery<Users>(CollectionUri, new SqlQuerySpec
{
QueryText = queryText,
Parameters = sqlParameterCollection
}).ToList();
The following gives you a SQL query, you can then run in your DocumentDB Collection, to get the Documents by their IDs.
var query = $"SELECT * FROM p WHERE p.id IN ('{string.Join("', '", arrayOfIds)}')";
The DocumentDB SDK doesn't support parameterized IN queries.
Judging from the SO thread in the comment above, SQL does not either. As mentioned in the other thread, you can use LINQ as a workaround.
Why not use the ArrayContains method? Here is an example in node
sqlQuery = {
query: 'SELECT * FROM t WHERE ARRAY_CONTAINS(#idList, t.id)',
parameters: [
{
name: '#idList',
value: ['id1','id2','id3'],
},
],
};
I have two functions that each return the same list of objects. But, the one that uses TSQL is much faster than the one using Entity Framework and I do not understand why one would be faster than the other. Is it possible to modify my EF function to work as fast as the TSQL one?
Any help will be appreciated. My code is below:
TSQL:
public static List<ChartHist> ListHistory_PureSQL()
{
List<DataRow> listDataRow = null;
string srtQry = #"Select LoginHistoryID,
LoginDuration as LoginDuration_Pass,
0 as LoginDuration_Fail,
LoginDateTime,
LoginLocationID,
LoginUserEmailID,
LoginApplicationID,
LoginEnvironmentID,
ScriptFrequency,
LoginStatus,
Reason
From LoginHistory
Where LoginStatus = 'Pass'
UNION
Select LoginHistoryID,
0 as LoginDuration_Pass,
LoginDuration as LoginDuration_Fail,
LoginDateTime,
LoginLocationID,
LoginUserEmailID,
LoginApplicationID,
LoginEnvironmentID,
ScriptFrequency,
LoginStatus,
Reason
From LoginHistory
Where LoginStatus = 'Fail'";
using (SqlConnection conn = new SqlConnection(Settings.ConnectionString))
{
using (SqlCommand objCommand = new SqlCommand(srtQry, conn))
{
objCommand.CommandType = CommandType.Text;
DataTable dt = new DataTable();
SqlDataAdapter adp = new SqlDataAdapter(objCommand);
conn.Open();
adp.Fill(dt);
if (dt != null)
{
listDataRow = dt.AsEnumerable().ToList();
}
}
}
var listChartHist = (from p in listDataRow
select new ChartHist
{
LoginHistoryID = p.Field<Int32>("LoginHistoryID"),
LoginDuration_Pass = p.Field<Int32>("LoginDuration_Pass"),
LoginDuration_Fail = p.Field<Int32>("LoginDuration_Fail"),
LoginDateTime = p.Field<DateTime>("LoginDateTime"),
LoginLocationID = p.Field<Int32>("LoginLocationID"),
LoginUserEmailID = p.Field<Int32>("LoginUserEmailID"),
LoginApplicationID = p.Field<Int32>("LoginApplicationID"),
LoginEnvironmentID = p.Field<Int32>("LoginEnvironmentID"),
ScriptFrequency = p.Field<Int32>("ScriptFrequency"),
LoginStatus = p.Field<String>("LoginStatus"),
Reason = p.Field<String>("Reason")
}).ToList();
return listChartHist;
}
EF:
public static List<ChartHist> ListHistory()
{
using (var db = new LatencyDBContext())
{
var loginHist = (from hist in db.LoginHistories
select new { LoginHistory = hist }).ToList();
//PUT LOGIN HISTORY RECORDS INTO A LOCAL LIST
var listHistory = new List<ChartHist>();
foreach (var item in loginHist)
{
var localHistData = new ChartHist();
localHistData.LoginHistoryID = item.LoginHistory.LoginHistoryID;
//split up the duration for pass and fail values
if (item.LoginHistory.LoginStatus.ToUpper() == "PASS")
{
localHistData.LoginDuration_Pass = Convert.ToDouble(item.LoginHistory.LoginDuration);
localHistData.LoginDuration_Fail = 0;
}
else if (item.LoginHistory.LoginStatus.ToUpper() == "FAIL")
{
localHistData.LoginDuration_Pass = 0;
localHistData.LoginDuration_Fail = Convert.ToDouble(item.LoginHistory.LoginDuration);
}
localHistData.LoginDateTime = item.LoginHistory.LoginDateTime;
localHistData.LoginLocationID = item.LoginHistory.LoginLocationID;
localHistData.LoginUserEmailID = item.LoginHistory.LoginUserEmailID;
localHistData.LoginApplicationID = item.LoginHistory.LoginApplicationID;
localHistData.LoginEnvironmentID = item.LoginHistory.LoginEnvironmentID;
localHistData.LoginStatus = item.LoginHistory.LoginStatus;
localHistData.Reason = item.LoginHistory.Reason;
localHistData.ScriptFrequency = item.LoginHistory.ScriptFrequency;
listHistory.Add(localHistData);
}
return listHistory;
}
}
Of course EF will take longer to execute than a plain old SQL query, and there's very little that you can do about it (except write the most optimal LINQ queries that you can).
There's a very simple reason why this is so. Running a direct SQL command will just send back the data, with no muss and no fuss attached to it, waiting for you to do the data manipulations to get it to the point where it fits nicely into whatever data structure you want it in. Running EF, on the other hand, means that not only does it run the SQL command, but it massages the data for you into objects that you can manipulate right away. That extra action of going through ADO.NET and converting the data into the objects automatically means that it will take longer than just doing the plain SQL query.
On the flip side of that coin, however, EF does provide a very nice and simple way to debug and solve whatever problems you might have from a specific query/function (like by any exceptions thrown).
I can't performance test this, but try this solution instead before you remove EF entirely:
var loginHist = db.LoginHistories.Where(item => item.LoginStatus.ToUpper() == "PASS" || item.LoginStatus.ToUpper() == "FAIL")
.Select(item => new ChartHist()
{
LoginHistoryID = item.LoginHistoryID,
LoginDuration_Pass = item.LoginStatus.ToUpper() == "PASS" ? Convert.ToDouble(item.LoginDuration) : 0,
LoginDuration_Fail = item.LoginStatus.ToUpper() == "FAIL" ? Convert.ToDouble(item.LoginDuration) : 0,
LoginDateTime = item.LoginDateTime,
LoginLocationID = item.LoginLocationID,
LoginUserEmailID = item.LoginUserEmailID,
LoginApplicationID = item.LoginApplicationID,
LoginEnvironmentID = item.LoginEnvironmentID,
LoginStatus = item.LoginStatus,
Reason = item.Reason,
ScriptFrequency = item.ScriptFrequency,
});
return loginHist.ToList();
This is the "correct" way to populate a new object from a select. It will only retrieve the data you care about, and will put it directly into the object, rather than converting it into an object and then converting it again, from one object to another.
Note: I prefer the functional calls to the from / select form, but it'd be correct either way.
I read some questions here but they all can be defined as separate variables but I think mine is little bit different:
var sliderRecordList = this._sliderService.GetAllAsQueryable();
var sliderModelList = sliderRecordList.Select(record => new SliderModel()
{
Id = record.Id,
SlideName = record.SlideName,
SlideOrder = record.SlideOrder,
SlideUrl = record.SlideUrl,
SlideImageUrl = Url.Content("~/Content/AhsenSliderImages/" + record.Id + ".jpg"),
Enabled = record.Enabled
});
The problem relies on where Url.Content() method is called. Any suggestion? I tried to remove Url.Content() method and didn't work.
Materalize the query first, then setup the UI concerns.
var sliderRecordList = this._sliderService.GetAllAsQueryable().ToList();
var sliderModelList = sliderRecordList
.Select(record => new SliderModel
{
Id = record.Id,
SlideName = record.SlideName,
SlideOrder = record.SlideOrder,
SlideUrl = record.SlideUrl,
SlideImageUrl = Url.Content("~/Content/AhsenSliderImages/" + record.Id + ".jpg"),
Enabled = record.Enabled
});
.ToList() will execute the query first.
On a side note, consider using AutoMapper to turn the above code into just a couple of lines:
var sliderRecordList = this._sliderService.GetAllAsQueryable().ToList();
var sliderModelList = Mapper.Map<ICollection<SliderRecord>, ICollection<SliderModel>>(sliderRecordList);
URL generation can be done in the View.
This is because the function Url.Content can not translated to its SQL equivalent function. Use AsEnumerable function to the list and give it a try
var sliderModelList = sliderRecordList.AsEnumerable.Select(record => new SliderModel()
{
Id = record.Id,
SlideName = record.SlideName,
SlideOrder = record.SlideOrder,
SlideUrl = record.SlideUrl,
SlideImageUrl = Url.Content("~/Content/AhsenSliderImages/" + record.Id + ".jpg"),
Enabled = record.Enabled
});
Good luck.