I dont want to do using a custom class.
var q = db.Query<dynamic>(query); //This does not work
query has joins and custom created columns from multiple tables.
You can check the PetaPoco.cs "ExecuteReader" method to see if it looks something like this(see code below):
my file did not have any code in the function so I model it after Execute scalar method.
this will return a generic DataTable that is perfectly bindable to datagrid.
however keep in mind that to make any changes to the data you will need to implement
your own CRUD methods as the resulting DataTable is readonly.
//Execute Reader
public DataTable ExecuteReader(string sql, params object[] args)
{
try
{
OpenSharedConnection();
try
{
using (var cmd = CreateCommand(_sharedConnection, sql, args))
{
var val = cmd.ExecuteReader();
OnExecutedCommand(cmd);
var dt = new DataTable();
dt.Load(val);
return dt; //(T)Convert.ChangeType(val, typeof(T));
}
}
finally
{
CloseSharedConnection();
}
}
catch (Exception x)
{
OnException(x);
throw;
}
}
public DataTable ExecuteReader(Sql sql)
{
return ExecuteReader(sql.SQL, sql.Arguments);
}
Create a class that contains the fields from the two tables you want to display in the grid.
Populate your query with a SQL statement that joins the tables and returns the columns you need.
Then
var q=db.Query<YourClassName>.Query(query)
should work.
You can create a database view, and then the T4 templates will automatically generate the class for that. You need to add
IncludeViews = true;
to Database.tt
Related
I have the following logic:
try
{
using (var contents = new StreamReader(file.InputStream).ReadToEnd())
{
var rows = contents.Split(new[] { Environment.NewLine }, StringSplitOptions.None);
rows.ForEach(r => mids.Add(r.Split(',')[0]));
}
}
catch(IOException e)
{}
finally
{
contents = null;
}
In the using statement I have an error in the question. It happened probably because I use .ReadToEnd() method.
Without the using statement I would need to use try/catch/finally for a clean up (to fix veracode resource clean up issue)
How can I fix that, so I don't need to use try\catch\finally and use only the using statement?
So, using should be used with object which implements IDisposable interface. You calling ReadToEnd method which returns string and contents is not a IDisposable (because string is not).
You should use it like this:
using (var streamReader = new StreamReader(file.InputStream))
{
var contents = streamReader.ReadToEnd();
// Some actions
}
You want to clean up StreamReader, contents will be collected by GC when method will finished because it has type string.
I'm trying to sort a Documents Collection using a java.util.ArrayList.
var myarraylist:java.util.ArrayList = new java.util.ArrayList()
var doc:NotesDocument = docs.getFirstDocument();
while (doc != null) {
myarraylist.add(doc)
doc = docs.getNextDocument(doc);
}
The reason I'm trying with ArrayList and not with TreeMaps or HashMaps is because the field I need for sorting is not unique; which is a limitation for those two objects (I can't create my own key).
The problem I'm facing is calling CustomComparator:
Here how I'm trying to sort my arraylist:
java.util.Collections.sort(myarraylist, new CustomComparator());
Here my class:
import java.util.Comparator;
import lotus.notes.NotesException;
public class CustomComparator implements Comparator<lotus.notes.Document>{
public int compare(lotus.notes.Document doc1, lotus.notes.Document doc2) {
try {
System.out.println("Here");
System.out.println(doc1.getItemValueString("Form"));
return doc1.getItemValueString("Ranking").compareTo(doc2.getItemValueString("Ranking"));
} catch (NotesException e) {
e.printStackTrace();
}
return 0;
}
}
Error:
Script interpreter error, line=44, col=23: Error calling method
'sort(java.util.ArrayList, com.myjavacode.CustomComparator)' on java
class 'java.util.Collections'
Any help will be appreciated.
I tried to run your SSJS code in a try-catch block, printing the error in exception in catch block and I got the following message - java.lang.ClassCastException: lotus.domino.local.Document incompatible with lotus.notes.Document
I think you have got incorrect fully qualified class names of Document and NotesException. They should be lotus.domino.Document and lotus.domino.NotesException respectively.
Here the SSJS from RepeatControl:
var docs:NotesDocumentCollection = database.search(query, null, 0);
var myarraylist:java.util.ArrayList = new java.util.ArrayList()
var doc:NotesDocument = docs.getFirstDocument();
while (doc != null) {
myarraylist.add(doc)
doc = docs.getNextDocument(doc);
}
java.util.Collections.sort(myarraylist, new com.mycode.CustomComparator());
return myarraylist;
Here my class:
package com.mycode;
import java.util.Comparator;
public class CustomComparator implements Comparator<lotus.domino.Document>{
public int compare(lotus.domino.Document doc1, lotus.domino.Document doc2) {
try {
// Numeric comparison
Double num1 = doc1.getItemValueDouble("Ranking");
Double num2 = doc2.getItemValueDouble("Ranking");
return num1.compareTo(num2);
// String comparison
// return doc1.getItemValueString("Description").compareTo(doc2.getItemValueString("Description"));
} catch (lotus.domino.NotesException e) {
e.printStackTrace();
}
return 0;
}
}
Not that this answer is necessarily the best practice for you, but the last time I tried to do the same thing, I realized I could instead grab the documents as a NotesViewEntryCollection, via SSJS:
var col:NotesViewEntryCollection = database.getView("myView").getAllEntriesByKey(mtgUnidVal)
instead of a NotesDocumentCollection. I just ran through each entry, grabbed the UNIDs for those that met my criteria, added to a java.util.ArrayList(), then sent onward to its destination. I was already sorting the documents for display elsewhere, using a categorized column by parent UNID, so this is probably what I should have done first; still on leading edge of the XPages/Notes learning curve, so every day brings something new.
Again, if your collection is not equatable to a piece of a Notes View, sorry, but for those with an available simple approach, KISS. I remind myself frequently.
I have this class using linq to sql, how do I implement the same by using normal sql in ASP.NET MVC 3 without use EF?
public ActionResult Index()
{
var List = (from c in db.OFFICE
join s in db.CAMPUS_UNIVERSITY on c.IdCampus equals s.IdCampus
join u in db.UNIVERSITY on s.IdUniversity equals u.IdUniversity
select u).ToList();
return View(List);
}
This is just a sample.(Tested & working ).That is y i am keeping the GetUniversities method inside the controller class . I suggest you to move the GetUniversities method to some service layer so that many UI/Controllers can use that.
public ActionResult Index()
{
var items= GetUniversities();
return View(items);
}
private List<DataRow> GetUniversities()
{
List<DataRow> list=null;
string srtQry = "SELECT U.* FROM Office O INNER JOIN
CampusUniversity CU ON O.IdCampus equals CU.IdCampus
INNER JOIN UNIVERSITY U ON U.IdUniversity=CU.IdUniversity";
string connString = "Database=yourDB;Server=yourServer;UID=user;PWD=password;";
using (SqlConnection conn = new SqlConnection(connString))
{
string strQry = "";
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)
{
list = dt.AsEnumerable().ToList();
}
}
}
return list;
}
Keep in mind that the GetCustomers method returns a List of DataRows. Not your custom domain entities. Entity framework is giving you the list of Domain Entities. So in the custom SQL case, you need to map the Data Row to an instance of your custom object yourself.
With LINQ, You can convert the List of DataRow to your custom objects like this
public ActionResult Index()
{
var items= GetCustomers();
var newItems = (from p in items
select new
{
Name= p.Field<String>("Name"),
CampusName= p.Field<String>("CampusName")
}).ToList();
return View(newItems);
}
This will give you a list of anonymous type which has 2 properties, Name and CampusName. Assuming Name and CampusName are 2 columns present in the result of your query.
EDIT2 : As per the Comment, To List these data in a view, Create a view called Index inside your controller( where we wrote this action methods) folder under Views Folder.We need to make it a strongly typed view. But Wait! What type are we going to pass to the view ?
Our result is annonymous type. So We will create a ViewModel in this case and instead of annonymous, We will return a List of the ViewModel.
public class UniversityViewModel
{
public string UniversityName { set;get;}
public string CampusName { set;get;}
}
Now we will update the code in our Index action like this.
var newItems = (from p in items
select new UserViewModel
{
UniversityName = p.Field<String>("Name"),
CampusName = p.Field<String>("CampusName")
}).ToList();
The only change is we now mentioned a type here. So the output is no more annonymous type. But known type.
Let us go back to our View and write code like this.
#model IEnumerable<SO_MVC.Models.UserViewModel>
#foreach (var item in Model)
{
<p>#item .UniversityName #item.CampusName</p>
}
This view is strongly typed to a collection of our ViewModel. As usual we are looping thru that and displaying. This should work fine. It is Tested.
This is not necessarily MVC specific. You could do the same thing in Webforms or Windows Forms, etc. Take a look at using ADO.NET for your queries or Dapper.
SELECT
u.*
FROM
OFFICE c
INNER JOIN CAMPUS_UNIVERSITY s ON c.IdCampus = s.IdCampus
INNER JOIN UNIVERSITY u ON s.IdUniversity = u.IdUniversity
I am trying to load a sortable jqgrid 3.5 from a query with multiple joins in it and having much difficulty as I am a novice with both Linq and jqgrid. In order to allow for sorting I first was attempting to load it using dynamic SQL.
Since I am pulling columns from multiple tables I assume my return will be a class object which I will populate (or will it be a table). How can I return a IQueryable custom class object when using dynamic SQL with multiple .JOIN clauses. If this is impossible how do I return IQueryable data from a stored procedure call. It is easy to create dynamic SQL in the stored procedure - I am unsure how to load my grid with it however.
Sorry if this is all over the place but I can't seem to find a way. If you can recommend the most straight forward way to load my sortable grid from a query which has multiple joins in I am much appreciated.
My controller code:
public ActionResult GridData(string sidx, string sord, int page, int rows)
{
EquipTrak eqt = new EquipTrak();
var equipment = eqt.GetGridEquipment(sidx, sord);
var dataJson = new
{
total = 10000,
page = 1,
records = 10000,
rows = (from e in equipment
select new
{
equip_id = e.equip_id,
cell = new string[] {
e.equip_id,
e.equipType,
e.makeType,
String.Format("{0:MM/dd/yyyy}", e.serv_due_dt)
}
}).ToArray()
};
return Json(dataJson);
}
}
my class code (incomplete):
namespace ULS_Site.Models
{
public class EquipTrak
{
uls_dbDataContext ulsDB = new uls_dbDataContext();
public IQueryable<equipmentCls> GetGridEquipment(string sidx, string sord)
{
try
{
return
Not sure if this is the best or worst solution but I used SQL Server views to handle all the joining required. I could then use .Orderby and .Where against the view which was in my data context.
I was wondering if there is any way to intercept and modify the sql generated from linq to Sql before the query is sent off?
Basically, we have a record security layer, that given a query like 'select * from records' it will modify the query to be something like 'select * from records WHERE [somesecurityfilter]'
I am trying to find the best way to intercept and modify the sql before its executed by the linq to sql provider.
Ok, first to directly answer your question (but read on for words of caution ;)), there is a way, albeit a finicky one, to do what you want.
// IQueryable<Customer> L2S query definition, db is DataContext (AdventureWorks)
var cs = from c in db.Customers
select c;
// extract command and append your stuff
DbCommand dbc = db.GetCommand(cs);
dbc.CommandText += " WHERE MiddleName = 'M.'";
// modify command and execute letting data context map it to IEnumerable<T>
var result = db.ExecuteQuery<Customer>(dbc.CommandText, new object[] { });
Now, the caveats.
You have to know which query is generated so you would know how to modify it, this prolongs development.
It falls out of L2S framework and thus creates a possible gaping hole for sustainable development, if anyone modifies a Linq it will hurt.
If your Linq causes parameters (has a where or other extension causing a WHERE section to appear with constants) it complicates things, you'll have to extract and pass those parameters to ExecuteQuery
All in all, possible but very troublesome. That being said you should consider using .Where() extension as Yaakov suggested. If you want to centrally controll security on object level using this approach you can create an extension to handle it for you
static class MySecurityExtensions
{
public static IQueryable<Customer> ApplySecurity(this IQueryable<Customer> source)
{
return source.Where(x => x.MiddleName == "M.");
}
}
//...
// now apply it to any Customer query
var cs = (from c in db.Customers select c).ApplySecurity();
so if you modify ApplySecurity it will automatically be applied to all linq queries on Customer object.
If you want to intercept the SQL generated by L2S and fiddle with that, your best option is to create a wrapper classes for SqlConnection, SqlCommand, DbProviderFactory etc. Give a wrapped instance of SqlConnection to the L2S datacontext constructor overload that takes a db connection. In the wrapped connection you can replace the DbProviderFactory with your own custom DbProviderFactory-derived class that returns wrapped versions of SqlCommand etc.
E.g.:
//sample wrapped SqlConnection:
public class MySqlConnectionWrapper : SqlConnection
{
private SqlConnecction _sqlConn = null;
public MySqlConnectionWrapper(string connectString)
{
_sqlConn = new SqlConnection(connectString);
}
public override void Open()
{
_sqlConn.Open();
}
//TODO: override everything else and pass on to _sqlConn...
protected override DbProviderFactory DbProviderFactory
{
//todo: return wrapped provider factory...
}
}
When using:
using (SomeDataContext dc = new SomeDataContext(new MySqlConnectionWrapper("connect strng"))
{
var q = from x in dc.SomeTable select x;
//...etc...
}
That said, do you really want to go down that road? You'll need to be able to parse the SQL statements and queries generated by L2S in order to modify them properly. If you can instead modify the linq queries to append whatever you want to add to them, that is probably a better alternative.
Remember that Linq queries are composable, so you can add 'extras' in a separate method if you have something that you want to add to many queries.
first thing come to my mind is to modify the query and return the result in Non-LINQ format
//Get linq-query as datatable-schema
public DataTable ToDataTable(System.Data.Linq.DataContext ctx, object query)
{
if (query == null)
{
throw new ArgumentNullException("query");
}
IDbCommand cmd = ctx.GetCommand((IQueryable)query);
System.Data.SqlClient.SqlDataAdapter adapter = new System.Data.SqlClient.SqlDataAdapter();
adapter.SelectCommand = (System.Data.SqlClient.SqlCommand)cmd;
DataTable dt = new DataTable("sd");
try
{
cmd.Connection.Open();
adapter.FillSchema(dt, SchemaType.Source);
adapter.Fill(dt);
}
finally
{
cmd.Connection.Close();
}
return dt;
}
try to add your condition to the selectCommand and see if it helps.
Try setting up a view in the DB that applies the security filter to the records as needed, and then when retrieving records through L2S. This will ensure that the records that you need will not be returned.
Alternatively, add a .Where() to the query before it is submitted that will apply the security filter. This will allow you to apply the filter programmatically (in case it needs to change based on the scenario).