Unable to connect Azure Function App with Database (using .net core 2.1) - asp.net-core

Question

Please note (Environment):
Function App: Version 2,
Target Framework: .Net Core 2.1
I am developing a Function App, that will work like Web Api. This Function App will return the data from database tables, also it'll manipulate files in Azure storage(Blob). But I am stuck as I am unable to create ConnectionString from local.settings.json file. Ideally the connection string should be created by default as I followed some tutorials & no where mentioned any extra steps to create default connectionstring value, just need to create it in local.settings.json file.
following is my local.settings.json file content:-
{
"ConnectionStrings": {
"mycs": "data source=servername;initial catalog=dbname;user id=XXXX;password=XXXX;MultipleActiveResultSets=True;"
},
"IsEncrypted": false,
"Values": {
"AzureWebJobsStorage": "",
"FUNCTIONS_WORKER_RUNTIME": "dotnet",
"mycs": "data source=servername;initial catalog=dbname;user id=XXXX;password=XXXX;MultipleActiveResultSets=True;"
}
}
following is my HttpTrigger file:
namespace my_api
{
public class myDataContext : DbContext
{
public myDataContext() : base(GetConnectionString()) { }
private static string GetConnectionString()
{
const string providerName = "System.Data.SqlClient";
const string metadata = #"res://*/MYDB.csdl|res://*/MYDB.ssdl|res://*/MYDB.msl";
try
{
string connectString = ConfigurationManager.ConnectionStrings["mycs"].ToString();
// Initialize the connection string builder for the
// underlying provider.
SqlConnectionStringBuilder sqlBuilder = new SqlConnectionStringBuilder(connectString);
// Set the properties for the data source.
//sqlBuilder.IntegratedSecurity = true;
sqlBuilder.MultipleActiveResultSets = true;
// Build the SqlConnection connection string.
string providerString = sqlBuilder.ToString();
// Initialize the EntityConnectionStringBuilder.
EntityConnectionStringBuilder entityBuilder = new EntityConnectionStringBuilder();
//Set the provider name.
entityBuilder.Provider = providerName;
// Set the provider-specific connection string.
entityBuilder.ProviderConnectionString = providerString;
// Set the Metadata location.
entityBuilder.Metadata = metadata;
return entityBuilder.ConnectionString;
}
catch { }
var connectionstring = Environment.GetEnvironmentVariable("mycs");
return connectionstring;
}
public DbSet<flowerset> flowersets
{
get;
set;
}
}
}
Following is the code for :
namespace my_api
{
public static class helpService
{
[FunctionName("helpService_get")]
public static async Task> Run(
[HttpTrigger(AuthorizationLevel.Function, "get", Route = null)] HttpRequest req,
ILogger log, ExecutionContext context)
{
log.LogInformation("C# HTTP trigger function processed a request helpService_get).");
try {
int page = 0;
int pageSize = 20;
myDataContext entity = new myDataContext();
if (page == 0 && pageSize == 0)
{
return entity.helpsets.ToList();
}
if (pageSize <= 0) { pageSize = 20; }
entity.helpsets.OrderByDescending(x => x.id).Skip((page - 1) * pageSize).Take(pageSize).ToList();
}
catch (Exception exx) {
log.LogInformation("Exception changed (helpService_get): "+exx.Message);
}
return null;
}
}//End of Class
}//End of Namespace
I am getting following error on line entity.helpsets.OrderByDescending(x => x.id).Skip((page - 1) * pageSize).Take(pageSize).ToList();:
Unable to determine the provider name for provider factory of type 'System.Data.SqlClient.SqlClientFactory'. Make sure that the ADO.NET provider is installed or registered in the application config.

Answer 1

According to my test, we can use System.Data.SqlClient to connect Azure SQL in Azure function V2.0. For example
Create an Azure Function with Visual Studio 2019
Install System.Data.SqlClient package(the version I sue is 4.5.1)
Develop the function
local.settings.json file content
"ConnectionStrings": {
"mycs": "Data Source="";Initial Catalog=DotNetAppSqlDb20190826105048_db;User Id="";Password="" "
},
"IsEncrypted": false,
"Values": {
"AzureWebJobsStorage": "",
"FUNCTIONS_WORKER_RUNTIME": "dotnet"
}
}
Code
[FunctionName("Function1")]
public static async Task<IActionResult> Run(
[HttpTrigger(AuthorizationLevel.Anonymous, "get", "post", Route = null)] HttpRequest req,
ILogger log)
{
log.LogInformation("C# HTTP trigger function processed a request.");
string name = req.Query["name"];
string requestBody = await new StreamReader(req.Body).ReadToEndAsync();
dynamic data = JsonConvert.DeserializeObject(requestBody);
name = name ?? data?.name;
try
{
var connectionstring = System.Environment.GetEnvironmentVariable($"ConnectionStrings:mycs"); ;
using (SqlConnection connection = new SqlConnection(connectionstring))
{
connection.Open();
log.LogInformation(" sql login success");
StringBuilder sb = new StringBuilder();
sb.Append("select * from dbo.Todoes");
String sql = sb.ToString();
using (SqlCommand command = new SqlCommand(sql, connection))
{
using (SqlDataReader reader = command.ExecuteReader())
{
while (reader.Read())
{
log.LogInformation("{0} {1}", reader.GetInt32(0), reader.GetString(1));
}
}
}
connection.Close();
}
}
catch (SqlException e)
{
Console.WriteLine(e.ToString());
}
return name != null
? (ActionResult)new OkObjectResult($"Hello, {name}")
: new BadRequestObjectResult("Please pass a name on the query string or in the request body");
}
For more details, please refer to the document