Is there a way i can reuse this code in C# - c#

Is there a way i can reuse this codes in executing SQL transaction, i want to make it a method so i can put parameters to execute other stored procedures,
can you guys help me to design a good coding structure?
try {
using (SqlConnection con = new SqlConnection(connectionString))
{
using (SqlCommand cmd = new SqlCommand("InsertUser2Sp", con) {
CommandType = CommandType.StoredProcedure
}) {
cmd.Parameters.AddWithValue("#UserID", useridStr);
cmd.Parameters.AddWithValue("#Firstname", firstnStr);
cmd.Parameters.AddWithValue("#Middlename", middleNstr);
cmd.Parameters.AddWithValue("#Lastname", lastnStr);
cmd.Parameters.AddWithValue("#UserAge", ageInt);
cmd.Parameters.AddWithValue("#HomeAddress", homeaddStr);
con.Open();
cmd.ExecuteNonQuery();
}
}
} catch (Exception ex) {
MessageBox.Show("Could not connect to database. Check settings. " + ex.Message, "Connection Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
MessageBox.Show(ex.Message);
}
}

I will share a generic method here . All you need to do is to build an object with the same property names (including cases) same with the parameters in your SP.
protected internal string GetSingleValue_String(String spname, Object entity)
{
Object res = new Object();
String conString = String.Empty;
using (SqlConnection con = new SqlConnection(ConnectionString))
{
con.Open();
SqlCommand cmd = new SqlCommand(spname, con);
cmd.CommandType = CommandType.StoredProcedure;
if (entity != null)
{
SqlCommandBuilder.DeriveParameters(cmd);
PropertyInfo entitymember = default(PropertyInfo);
foreach (SqlParameter _param in cmd.Parameters)
{
if (_param.Direction == ParameterDirection.Input)
{
entitymember = entity.GetType().GetProperty(_param.ParameterName.Replace("#", ""));
var entityValue = entitymember.GetValue(entity, null);
String _paramvalue = entityValue != null ? entityValue.ToString() : null;
_param.Value = (string.IsNullOrEmpty(_paramvalue) || _paramvalue == string.Empty ? null : _paramvalue);
}
}
}
res = cmd.ExecuteScalar();
cmd.Connection.Close();
entity = null;
cmd = null;
if(res==null)
res = "";
else if (String.IsNullOrEmpty(res.ToString()))
res = "";
return res.ToString();
}
}
So in your example, create a new class that have the same definition as your SP parameters.
class NewClass()
{
public string UserID { get; set; }
public string Firstname { get; set; }
public string Middlename { get; set; }
public string Lastname { get; set; }
public string UserAge { get; set; }
public string HomeAddress { get; set; }
}
And will call the method like this.
var newClass = new NewClass
{
UserID = "UserId",
Firstname = "Firstname",
Middlename = "Middlename",
Lastname = "Lastname",
UserAge = "UserAge",
HomeAddress = "HomeAddress"
}
var res = GetSingleValue_String("InsertUser2Sp", newClass);
Don'd mind the return type.

Related

C# Web API Parameter Always Returns All Values Instead of One

I am working on a Web API in C# and am getting my data from a SQL Database. The Get method returns all rows of (student) data, however even when I put a single student number in the GET call, it still returns all rows of data instead of a single row for the specified student. In my Roles Class I have;
public class Roles
{
List<Roles> studentRoles = new List<Roles>();
public string UserName { get; set; }
public string PersonName { get; set; }
public string Profile { get; set; }
public string Level { get; set; }
public int Year { get; set; }
public string Department { get; set; }
}
public class readRoles : Roles
{
public readRoles(DataRow dataRow)
{
UserName = (string)dataRow["UserName"];
PersonName = (string)dataRow["PersonName"];
Profile = (string)dataRow["Profile"];
Level = (string)dataRow["Level"];
Year = Convert.ToInt32(dataRow["Year"]);
Department = (dataRow["Department"] == DBNull.Value) ? "No Department" : dataRow["Department"].ToString();
}
public string UserName { get; set; }
public string PersonName { get; set; }
public string Profile { get; set; }
public string Level { get; set; }
public int Year { get; set; }
public string Department { get; set; }
}
In my Controller I have this;
List<Roles> studentRoles = new List<Roles>();
private SqlDataAdapter _adapter;
public IEnumerable<Roles> Get()
{
//Create link to database
string connString;
SqlConnection con;
connString = #"XXX";
DataTable _dt = new DataTable();
con = new SqlConnection(connString);
con.Open();
var sql = "some sql here";
SqlCommand CMD = new SqlCommand();
CMD.Connection = con;
CMD.CommandText = sql;
CMD.CommandType = System.Data.CommandType.Text;
SqlDataReader dr = CMD.ExecuteReader();
_adapter = new SqlDataAdapter
{
SelectCommand = new SqlCommand(sql, con)
};
_adapter.Fill(_dt);
List<Roles> roles = new List<Roles>(_dt.Rows.Count);
if (_dt.Rows.Count > 0)
{
foreach (DataRow studentrole in _dt.Rows)
{
roles.Add(new readRoles(studentrole));
}
}
return roles;
}
The above returns all the data as it should. To return a single row of data, I have the below Method but it still returns every single row instead of the row for the specified one when I do e.g. https://localhost:XXXXX/custom-roles-api/campusCustomRoles/12345;
[HttpGet]
public IHttpActionResult Get(string userName)
{
string connString;
SqlConnection con;
connString = #"XXX";
DataTable _dt = new DataTable();
con = new SqlConnection(connString);
con.Open();
var sql = "select distinct .... where student_reference = " + userName +;
SqlCommand CMD = new SqlCommand();
CMD.Connection = con;
CMD.CommandText = sql;
CMD.CommandType = System.Data.CommandType.Text;
SqlDataReader dr = CMD.ExecuteReader();
_adapter = new SqlDataAdapter
{
SelectCommand = new SqlCommand(sql, con)
};
_adapter.Fill(_dt);
List<Roles> roles = new List<Roles>(_dt.Rows.Count);
if (_dt.Rows.Count > 0)
{
foreach (DataRow studentrole in _dt.Rows)
{
roles.Add(new readRoles(studentrole));
}
}
var singlestu = roles.FirstOrDefault(e => e.UserName == userName);
return Ok(singlestu)
;
}
In the above example, I expect only data for student 12345 to be returned, but alas, all records are retrieved. In my WebConfig file, I have a custom Route like so;
public static void Register(HttpConfiguration config)
{
// Web API routes
// This is the original Route
//config.MapHttpAttributeRoutes();
//config.Routes.MapHttpRoute(
// name: "DefaultApi",
// routeTemplate: "api/{Controller}/{id}",
// //routeTemplate: "api/{controller}/{action}/{id}",
// defaults: new { id = RouteParameter.Optional }
//);
// Custom Route
config.MapHttpAttributeRoutes();
// Define route
System.Web.Http.Routing.IHttpRoute rolesRoute = config.Routes.CreateRoute("custom-roles-api/{controller}/{id}",
new { id = RouteParameter.Optional }, null);
// Add route
config.Routes.Add("DefaultApi", rolesRoute);
}
Not sure where I have gone wrong and would be grateful for any pointers.
Many thanks in advance.
EDIT: As requested, please see below code when I used parameters;
[HttpGet]
public IHttpActionResult Get(string userName)
{
string connString;
SqlConnection con;
connString = #"XXXX";
DataTable _dt = new DataTable();
con = new SqlConnection(connString);
con.Open();
var sql = "select distinct .... where student_reference =#UserName " +
"and department ='LAW' " +;
SqlParameter param = new SqlParameter();
param.ParameterName = "#UserName";
param.Value = UserName;
SqlCommand CMD = new SqlCommand();
CMD.Connection = con;
CMD.CommandText = sql;
CMD.CommandType = System.Data.CommandType.Text;
SqlDataReader dr = CMD.ExecuteReader();
_adapter = new SqlDataAdapter
{
SelectCommand = new SqlCommand(sql, con)
};
_adapter.Fill(_dt);
List<Roles> roles = new List<Roles>(_dt.Rows.Count);
if (_dt.Rows.Count > 0)
{
foreach (DataRow studentrole in _dt.Rows)
{
roles.Add(new readRoles(studentrole));
}
}
var singlestu = roles.FirstOrDefault(e => e.UserName == userName);
return Ok(singlestu)
;
}
After much head-cracking, I go it to work by converting the UserName to type int in the Roles class and the source query.

Insert null datetime from sql table into datagridview silverlight

I have problem with null values, I want to insert from sql table nulls ( from datetime column) into datagridview, and datagridview return error.
Communication Exception was unhandled by user code
Code:
public class Pismo
{
public int Id { get; set; }
public string PW { get; set; }
public DateTime? Data_Wysylki { get; set; }
}
public ObservableCollection<Pismo> ReadPisma(int id_pismo)
{
ObservableCollection<Pismo> result = new ObservableCollection<Pismo>();
string nwConn = System.Configuration.ConfigurationManager.ConnectionStrings["MyConnectionString"].ConnectionString;
SqlDataReader dr;
SqlConnection conn = new SqlConnection(nwConn);
try
{
SqlCommand cmd = new SqlCommand();
cmd.CommandType = CommandType.StoredProcedure;
cmd.Connection = conn;
cmd.CommandText = "INSERT";
cmd.Parameters.AddWithValue("#id", id);
conn.Open();
dr = cmd.ExecuteReader();
while (dr.Read())
{
Pismo wiersz = new Pismo();
wi.Id = dr.GetInt32(0);
wi.PW = dr.GetString(1);
wi.Data_Wysylki = dr.GetDateTime(2);
result.Add(wi);
}
dr.Close();
return result;
}
catch (SqlException e)
{
Pismo wi = new Pismo();
wi.Id = e.Message;
result.Add(wi);
return result;
}
finally
{
conn.Close();
};
}
<sdk:DataGridTextColumn Header="Data WysyƂki" Binding="{Binding Data_Wysylki, StringFormat='yyyy/MM/dd'}"/>
I try to add this below
if (wi.Data_Wysylki.HasValue) wi.Data_Wysylki = dr.GetDateTime(16);
after that error didnt show but in datagridview all column (even with some dates) was null

I get the error 'not all code paths return a value' in a try catch block

Please see the code below, it is MVC, I'm trying to create a IEnumerable view. The error I'm getting is'not all code path return a value' how can I correct the error?
public class CustomerSummary
{
public string ContactName { get; set; } // Customer table
public string City { get; set; } // Customer table
public string PostalCode { get; set; } // Order table
public string ShipName { get; set; } // Order table
public string ProductName { get; set; } // Product table
public bool Discontinued { get; set; } // product table
}
Controller
public class CustomerSummaryController : Controller
{
//
// GET: /CustomerSummary/
private CustomerSummaries _customerSummaries = new CustomerSummaries();
public ViewResult Index()
{
IEnumerable<CustomerSummary> summaries = _customerSummaries.GetAll();
return View(summaries);
}
}
Data layer
public IEnumerable<CustomerSummaries> GetAll(/* to do put connection string here */)
{
try
{
SqlCommand cmd = new SqlCommand("GetAll", conn);
cmd.CommandType = CommandType.StoredProcedure;
SqlDataAdapter da = new SqlDataAdapter(cmd);
SqlDataReader sdr;
conn.Open();
sdr = cmd.ExecuteReader();
while (sdr.Read())
{
if (sdr.IsDBNull(sdr.GetOrdinal("ContactName")) != true)
{
sdr["ContactName"].ToString();
}
}
}
catch (Exception)
{
throw;
}
finally
{
conn.Close();
}
}
I'm making a fair amount of assumptions here, but I think this is what you want:
public IEnumerable<CustomerSummary> GetAll(SqlConnection conn)
{
var result = new List<CustomerSummary>();
try
{
SqlCommand cmd = new SqlCommand("GetAll", conn);
cmd.CommandType = CommandType.StoredProcedure;
SqlDataAdapter da = new SqlDataAdapter(cmd);
SqlDataReader sdr;
conn.Open();
sdr = cmd.ExecuteReader();
while (sdr.Read())
{
var cs = new CustomerSummary();
if (sdr.IsDBNull(sdr.GetOrdinal("ContactName")) != true)
{
cs.ContactName = sdr["ContactName"].ToString();
}
// repeat the above if-block to add more info if needed...
// add the CustomerSummary to the result
result.Add(cs);
}
}
catch (Exception)
{
throw;
}
finally
{
conn.Close();
}
return result;
}

Generic List linked with Database using Reflection

I have a class
public class UserInfo
{
public int ID { get; set; }
public string Name { get; set; }
public string Address { get; set; }
}
And I need to make a link between the database, with this code:
using (SqlDataReader reader = cmd.ExecuteReader())
{
while (reader.HasRows)
{
}
}
Using Reflection on all the lines of the database.
And store them into a generic List:
List<UserInfo> users = new List<UserInfo>();
I GOT IT !!
I GOT IT !!
This is the result, maybe someone needs it !!
public List<UserInfo> GetAllUsers()
{
List<UserInfo> users = new List<UserInfo>();
try
{
using (SqlConnection sqlConnection = connectionString)
{
using (SqlCommand cmd = new SqlCommand())
{
cmd.CommandText = "dbo.GetAllUsers";
cmd.CommandType = CommandType.StoredProcedure;
cmd.Connection = sqlConnection;
sqlConnection.Open();
using (SqlDataReader dataReader = cmd.ExecuteReader())
{
if (dataReader.HasRows)
{
while (dataReader.Read())
{
UserInfo user = new UserInfo();
PropertyInfo[] pList = typeof(UserInfo).GetProperties();
foreach (PropertyInfo pi in pList)
{
object value = dataReader[pi.Name];
if (!value.GetType().Equals(typeof(DBNull)))
{
users.GetType().GetProperty(pi.Name, BindingFlags.Public | BindingFlags.Instance).SetValue(user, value, null);
}
}
users.Add(user);
}
}
else
{
users = null;
}
}
}
sqlConnection.Close();
}
}
catch (Exception)
{
return null;
}
return users;
}

Using Dapper with Oracle stored procedures which return cursors

How would one go about using Dapper with Oracle stored procedures which return cursors?
var p = new DynamicParameters();
p.Add("foo", "bar");
p.Add("baz_cursor", dbType: DbType.? , direction: ParameterDirection.Output);
Here, the DbType is System.Data.DbType which does not have a Cursor member. I've tried using DbType.Object but that does not work with both OracleClient and OracleDataAcess.
What would be a possible way to use OracleType or OracleDbType instead?
Thanks for the solution here. I achieved the same thing with a little less code using a simple DynamicParameter decorator:
public class OracleDynamicParameters : SqlMapper.IDynamicParameters
{
private readonly DynamicParameters dynamicParameters = new DynamicParameters();
private readonly List<OracleParameter> oracleParameters = new List<OracleParameter>();
public void Add(string name, object value = null, DbType? dbType = null, ParameterDirection? direction = null, int? size = null)
{
dynamicParameters.Add(name, value, dbType, direction, size);
}
public void Add(string name, OracleDbType oracleDbType, ParameterDirection direction)
{
var oracleParameter = new OracleParameter(name, oracleDbType, direction);
oracleParameters.Add(oracleParameter);
}
public void AddParameters(IDbCommand command, SqlMapper.Identity identity)
{
((SqlMapper.IDynamicParameters)dynamicParameters).AddParameters(command, identity);
var oracleCommand = command as OracleCommand;
if (oracleCommand != null)
{
oracleCommand.Parameters.AddRange(oracleParameters.ToArray());
}
}
}
You would have to implement:
public interface IDynamicParameters
{
void AddParameters(IDbCommand command, Identity identity);
}
Then in the AddParameters callback you would cast the IDbCommand to an OracleCommand and add the DB specific params.
Add this class to your project
and your code should like below :-
var p = new OracleDynamicParameters();
p.Add("param1", pAuditType);
p.Add("param2", pCommnId);
p.Add("outCursor", dbType: OracleDbType.RefCursor, direction: ParameterDirection.Output);
using (var multi = cnn.QueryMultiple("procedure_name", param: p, commandType: CommandType.StoredProcedure))
{
var data = multi.Read();
return data;
}
Just to elaborate on Sams suggestion here's what I came up with. Note that this code is brittle and is now just for Oracle.
Modified Dapper 1.7
void SqlMapper.IDynamicParameters.AddParameters(IDbCommand command, SqlMapper.Identity identity)
{
if (templates != null)
{
foreach (var template in templates)
{
var newIdent = identity.ForDynamicParameters(template.GetType());
Action<IDbCommand, object> appender;
lock (paramReaderCache)
{
if (!paramReaderCache.TryGetValue(newIdent, out appender))
{
appender = SqlMapper.CreateParamInfoGenerator(newIdent);
paramReaderCache[newIdent] = appender;
}
}
appender(command, template);
}
}
foreach (var param in parameters.Values)
{
string name = Clean(param.Name);
bool add = !((Oracle.DataAccess.Client.OracleCommand)command).Parameters.Contains(name);
Oracle.DataAccess.Client.OracleParameter p;
if(add)
{
p = ((Oracle.DataAccess.Client.OracleCommand)command).CreateParameter();
p.ParameterName = name;
} else
{
p = ((Oracle.DataAccess.Client.OracleCommand)command).Parameters[name];
}
var val = param.Value;
p.Value = val ?? DBNull.Value;
p.Direction = param.ParameterDirection;
var s = val as string;
if (s != null)
{
if (s.Length <= 4000)
{
p.Size = 4000;
}
}
if (param.Size != null)
{
p.Size = param.Size.Value;
}
if (param.DbType != null)
{
p.DbType = param.DbType.Value;
}
if (add)
{
if (param.DbType != null && param.DbType == DbType.Object)
{
p.OracleDbType = Oracle.DataAccess.Client.OracleDbType.RefCursor;
((Oracle.DataAccess.Client.OracleCommand)command).Parameters.Add(p);
}
else
{
((Oracle.DataAccess.Client.OracleCommand)command).Parameters.Add(p);
}
}
param.AttachedParam = p;
}
}
Test code
class Program
{
static void Main(string[] args)
{
OracleConnection conn = null;
try
{
const string connString = "DATA SOURCE=XE;PERSIST SECURITY INFO=True;USER ID=HR;PASSWORD=Adv41722";
conn = new OracleConnection(connString);
conn.Open();
var p = new DynamicParameters();
p.Add(":dep_id", 60);
p.Add(":employees_c", dbType: DbType.Object, direction: ParameterDirection.Output);
p.Add(":departments_c", dbType: DbType.Object, direction: ParameterDirection.Output);
// This will return an IEnumerable<Employee> // How do I return both result?
var results = conn.Query<Employee>("HR_DATA.GETCURSORS", p, commandType: CommandType.StoredProcedure);
}
catch (Exception exception)
{
Console.WriteLine(exception);
throw;
}
finally
{
if (conn != null && conn.State == ConnectionState.Open)
{
conn.Close();
}
}
Console.WriteLine("Fininhed!");
Console.ReadLine();
}
}
class Employee
{
public int Employee_ID { get; set; }
public string FIRST_NAME { get; set; }
public string LAST_NAME { get; set; }
public string EMAIL { get; set; }
public string PHONE_NUMBER { get; set; }
}

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