I am looking to query a table like the following sql:
select * from itd093 where rowid='Cumn99AAAAMzAAAAAJ'
It could find a unique record in the ADS architect client. However, when this query was sent from the code level through the .NET data provider, it return none result from the database server.
Does anyone have ideas on how I can make the sql above return the result through the .NET data provider?
Some sample code here:
public void DataProviderTest()
{
using (AdsConnection conn = new AdsConnection(#"Data Source=D:\Development\FDDB;ServerType=ADS_LOCAL_SERVER;TableType=ADS_CDX;TrimTrailingSpaces=TRUE;"))
{
conn.Open();
AdsCommand cmd = new AdsCommand("select * from itd093 where rowid='Cumn99AAAAMzAAAAAJ'", conn);
AdsDataReader reader = cmd.ExecuteReader(System.Data.CommandBehavior.CloseConnection);
if (!reader.Read())
throw new Exception("no records");
}
}
Thanks Mark for pointing out that the .NET data provider and the Advantage Data Architect should return the same result.
The problem to be the different connection strings. From the help documentation, it says,the first six characters of the ROWID represent the database ID. It is based on the connection path.
I was mistakenly copy a rowid from the data architect to test with data provider, and the connection strings are different. That's why I couldn't get a result returned from the data provider as it does from the data architect.
Related
One aspect of an ASP.net core (6) MVC app I am working on needs to query an SQL View that already resides in an Azure SQL MI.
I need to be able to query this SQL View to be able to retrieve the data based on user input but with the following conditions.
I cannot use Entity Framework.
The connection has to be read only.
This has to be database first.
As of yet I do not have access to this View or any of the tables it draws from. However I am expected to have code ready to plug a connection string into.
Unfortunately any resources I have been able to find don't seem to apply to my specific conditions. So any advice in what direction or approach would work best would be appreciated.
Those are by no means "silly" conditions. You didn't specify the language or the database but I'll make assumptions
I cannot use Entity Framework
Just use standard ado.net
https://learn.microsoft.com/en-us/dotnet/framework/data/adonet/ado-net-code-examples#sqlclient
(I know that Link only answers are frowned upon)
The connection has to be read only.
Ensure that the account you connect under is read only. In SQL Server this is achieved by making you a member of the db_datareader group. This is something that should be enforced by the DBA that gives you an account
This has to be database first.
That's not really relevant. Just use the linked sample code to read from the existing view.
Literal copy paste of code at the link above:
using System;
using System.Data;
using System.Data.SqlClient;
class Program
{
static void Main()
{
string connectionString =
"Data Source=(local);Initial Catalog=Northwind;"
+ "Integrated Security=true";
// Provide the query string with a parameter placeholder.
string queryString =
"SELECT ProductID, UnitPrice, ProductName from dbo.products "
+ "WHERE UnitPrice > #pricePoint "
+ "ORDER BY UnitPrice DESC;";
// Specify the parameter value.
int paramValue = 5;
// Create and open the connection in a using block. This
// ensures that all resources will be closed and disposed
// when the code exits.
using (SqlConnection connection =
new SqlConnection(connectionString))
{
// Create the Command and Parameter objects.
SqlCommand command = new SqlCommand(queryString, connection);
command.Parameters.AddWithValue("#pricePoint", paramValue);
// Open the connection in a try/catch block.
// Create and execute the DataReader, writing the result
// set to the console window.
try
{
connection.Open();
SqlDataReader reader = command.ExecuteReader();
while (reader.Read())
{
Console.WriteLine("\t{0}\t{1}\t{2}",
reader[0], reader[1], reader[2]);
}
reader.Close();
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
Console.ReadLine();
}
}
I want to create a web API controller that returns product details with id. Using stored procedure calls from a database class, not DB context. Sending Request with ID & getting a response with Jason's values.
I saw many examples but they are directly using stored procedures from the DB context. But I want to introduce a connection string & call that method in business class than a business class call to the controller with the response return.
Please help with a small example
Here is one example. You can choose between using SQL Command or SQL Adapter, try searching a little bit more about it.
Programming isn't only writing a code it's also googling for solutions.
// Setup connection string to access local SQL Server 2000
string connectionString = "server=localhost;" +
"database=Northwind;uid=sa;pwd=manager";
// Instantiate the connection, passing the
// connection string into the constructor
SqlConnection con = new SqlConnection(connectionString);
// Open the connection
con.Open();
// Create and execute the query
SqlCommand cmd = new SqlCommand("SELECT * FROM Customers",con);
SqlDataReader reader = cmd.ExecuteReader();
// Iterate through the DataReader and display row
while(reader.Read()) {
Console.WriteLine("{0} - {1}",
reader.GetString(0), reader.GetString(1));
}
Source
I developed a website using Asp.Net MVC and Edmx database and I published this website on azure and my database is also on azure and I've a functionality on website that uploads excel record into database and that excel sheet contain almost 18000 records every time I upload that sheet it throw Timeout error after some time so what should I do.
Initially I was not using any command Timeout but after doing some research I'm using this in constructor
public ProfessionalServicesEntities()
: base("name=ProfessionalServicesEntities")
{
this.Database.CommandTimeout = 10000;
//this.Database.CommandTimeout = 0; //I tried this too.
//((IObjectContextAdapter)this).ObjectContext.CommandTimeout = 3600;
}
Here is the code of
function :-
public void SaveEquipments(IEnumerable<EquipSampleEntity> collection)
{
using (ProfessionalServicesEntities db = new ProfessionalServicesEntities())
{
string modelXml = XmlSerialization.ListToXml(collection.Where(x=>x.Type == Model).ToList());
string accessoryXml = XmlSerialization.ListToXml(collection.Where(x => x.Type == Accessory).ToList());
db.ImportEquipmentFile(modelXml, accessoryXml);
}
}
here is context file code for SP:-
public virtual int ImportEquipmentFile(string modelXml, string accessoryXml)
{
var modelXmlParameter = modelXml != null ?
new ObjectParameter("ModelXml", modelXml) :
new ObjectParameter("ModelXml", typeof(string));
var accessoryXmlParameter = accessoryXml != null ?
new ObjectParameter("AccessoryXml", accessoryXml) :
new ObjectParameter("AccessoryXml", typeof(string));
return ((IObjectContextAdapter)this).ObjectContext.ExecuteFunction("ImportEquipmentFile", modelXmlParameter, accessoryXmlParameter);
}
You may be processing the excel on upload itself and processing it row by row. You have two options, one is to schedule a background job to pickup the upload file and insert it to DB and complete the request.
Next option is to read the whole file in one go and do a single bulk insert into the DB.
There are too many things that can cause this. In Azure App Service there is a Front-end which has a timeout of 240 seconds. If your application takes more time, then you might run into this. This could be one of the probable causes.
In order to understand what is happening. Enabled Web Server Logging and Failed Request Tracing.
See this for how to proceed further: https://learn.microsoft.com/en-us/azure/app-service-web/web-sites-enable-diagnostic-log
Can someone please help me fix my connection string? I am an absolute beginner using the MS SQL Management Studio but I am an experienced C# programmer. I am trying to figure out how to connect to a local database on my PC. I just installed SQL server 2012 Express today and I created a table with one row of data. I am trying to access that table from a C# program. I've been looking for help calling a stored procedure (with no parameters) and it seems like I am doing everything right, but I get an exception error "Could not find stored procedure 'GetCustomers'." I have also tried changing my the procedure name to "dbo.GetCustomers" and also "SqlTest.dbo.GetCustomers" and also "SqlTest.GetCustomers", but nothing seems to work. Clearly I am not connecting to my database correctly. I've been working on this for 4 hours now so it's time for me to stop and find help. I think all I need is a good connection string and the proper syntax for the procedure.
Connect c = new Connect();
if(c.MakeConnection())
{
try
{
DataSet data = new DataSet();
SqlDataAdapter adaptor = new SqlDataAdapter();
//changed to use stored procedure
adaptor.SelectCommand = new SqlCommand("GetCustomers", c.MyConnect);
adaptor.SelectCommand.CommandType = CommandType.StoredProcedure;
//adaptor.SelectCommand.ExecuteNonQuery();//this throws an exception.
adaptor.Fill(data);//this throws an exception.
}
catch (Exception e)
{
Logger.WriteMessage(e.Message);
}
finally
{
c.CloseConnection();
}
My connection class contains the following:
string connection = Properties.Settings.Default.DatabaseConnectString;
sqlConnection = new SqlConnection(connection);
sqlConnection.Open();
Connection string I have tried which seem to connect OK:
Server=(localdb)\v11.0;Trusted_Connection=Yes;
Server=(localdb)\v11.0;Integrated Security=true;
My Database name is SqlTest. I have tried several variations in my connection string, but most of them throw a logon failed exception error. I verified that my windows user ID has admin privileges for the database.
Connection strings I have tried which cive me logon errors:
Server=(localdb)\v11.0;Initial Catalog=SqlTest;User ID=Raphael\couchpotato;Integrated Security=SSPI;Trusted_Connection=Yes;
Server=(localdb)\v11.0;Initial Catalog=dbo;User ID=Raphael\couchpotato;Integrated Security=SSPI;Trusted_Connection=Yes;
Server=(localdb)\v11.0;Database=SqlTest;Trusted_Connection=Yes;
Server=(localdb)\v11.0;Database=SqlTest;Integrated Security=true;
I guess all I needed was some sleep. ;-)
I needed to set all of my SQL server services to Automatic. For some reason, they were set to manual, and so they were not started.
Then, I also needed to set the correct server name in my connection string. This is the same server name that is used to logon when starting SQL Server Management Studio. Here is a connection string that connects and accesses the correct database and table:
Server=RAPHAEL\SQLEXPRESS;Database=SqlTest;Trusted_Connection=Yes;
I'm in a hoo-ha with my boss as I can't shift to using newer technologies until I have proof of some outstanding issues. One of the main concerns is how repositories deal with connections. One of the supposedly largest overheads is connecting and disconnecting to/from the database. If I have a repository where I do the following:
public ContractsControlRepository()
: base(ConfigurationManager.ConnectionStrings["AccountsConnectionString"].ToString()) { }
with the class like so:
public class ContractsControlRepository : DataContext, IContractsControlRepository
with functions like:
public IEnumerable<COContractCostCentre> ListContractCostCentres(int contractID)
{
string query = "SELECT C.ContractID, C.CCCode, MAC.CostCentre, C.Percentage FROM tblCC_Contract_CC C JOIN tblMA_CostCentre MAC ON MAC.CCCode = C.CCCode WHERE C.ContractID = {0}";
return this.ExecuteQuery<COContractCostCentre>(query, contractID);
}
Now if in my controller action called _contractsControlRepository.ListContractCostCentres(2) followed immediately by another call to the repository, does it use the same connection? When does the connection open in the controller? When is it closed?
Cheers
EDIT
I'm using hand-written LINQ as suggested by Steve Sanderson in his ASP.NET MVC book.
EDIT EDIT
To clarify, I'm using LINQ as my ORM, but I'm using raw SQL queries (as shown in the extract above) for querying. For example, here's a controller action:
public ActionResult EditBusiness(string id)
{
Business business = _contractsControlRepository.FetchBusinessByID(id);
return View(business);
}
I'm not opening/closing connections.
Here's a larger, more complete extract of my repo:
public class ContractsControlRepository : DataContext, IContractsControlRepository
{
public ContractsControlRepository()
: base(ConfigurationManager.ConnectionStrings["AccountsConnectionString"].ToString()) { }
public IEnumerable<COContractCostCentre> ListContractCostCentres(int contractID)
{
string query = "SELECT C.ContractID, C.CCCode, MAC.CostCentre, C.Percentage FROM tblCC_Contract_CC C JOIN tblMA_CostCentre MAC ON MAC.CCCode = C.CCCode WHERE C.ContractID = {0}";
return this.ExecuteQuery<COContractCostCentre>(query, contractID);
}
Then ContractsControlRepository is instantiated in my controller and used like _contractsControlRepository.ListContractCostCentres(2). Connections aren't opened manually, DataContext deals with that for me.
Without knowing the details of your ORM and how it connects the SQL database drivers will connection pool. When a connection is closed it is released back to the pool and kept open for X number of seconds (where X is configurable). If another connection is opened and all the parameters match (the server name, the application name, the database name, the authentication details etc.) then any free, but open connections in the pool will get reused instead of opening a brand new connection.
Having not read the book in question I don't know what "manual linq" actually is. If it's manual means you're getting the tables back youself then obviously you're doing the connection open/close. Linq to SQL will use a new connection object when a statement is finally executed at which point connection pooling comes into play - which means a new connection object may not be an actual new connection.