What is the difference between ExecuteStoreQuery and ExecuteStoreCommand

Question

In entityframework, we can use ExecuteStoreQuery or ExecuteStoreCommand to execute sql queries. So what is the difference between the two (which scenario is different)?

Thank.

Answer 1

The difference is obvious from MSDN

ExecuteStoredQuery

Executes a query directly to a data source that returns a sequence of typed results.

and MSDN

ExecuteStoreCommand

Executes an arbitrary command directly against the data source using an existing connection.

Example for ExecuteStoreQuery :

using (SchoolEntities context =
    new SchoolEntities())
{
    // The following three queries demonstrate 
    // three different ways of passing a parameter.
    // The queries return a string result type.

    // Use the parameter substitution pattern.
    foreach (string name in context.ExecuteStoreQuery<string>
        ("Select Name from Department where DepartmentID < {0}", 5))
    {
        Console.WriteLine(name);
    }

    // Use parameter syntax with object values.
    foreach (string name in context.ExecuteStoreQuery<string>
        ("Select Name from Department where DepartmentID < @p0", 5))
    {
        Console.WriteLine(name);
    }
    // Use an explicit SqlParameter.
    foreach (string name in context.ExecuteStoreQuery<string>
        ("Select Name from Department where DepartmentID < @p0",
            new SqlParameter { ParameterName = "p0", Value = 5 }))
    {
        Console.WriteLine(name);
    }
}

Example for ExecuteStoreCommand

public class DepartmentInfo
{
    private DateTime _startDate;
    private String _name;
    private Int32 _departmentID;

    public Int32 DepartmentID
    {
        get
        {
            return _departmentID;
        }
        set
        {
            _departmentID = value;
        }
    }
    public String Name
    {
        get
        {
            return _name;
        }
        set
        {
            _name = value;
        }
    }
    public DateTime StartDate
    {
        get
        {
            return _startDate;
        }
        set
        {
            _startDate = value;
        }
    }
}

public static void ExecuteStoreCommands()
{
    using (SchoolEntities context =
        new SchoolEntities())
    {

        int DepartmentID = 21;
        // Insert the row in the Department table. Use the parameter substitution pattern.
        int rowsAffected = context.ExecuteStoreCommand("insert Department values ({0}, {1}, {2}, {3}, {4})",
                        DepartmentID, "Engineering", 350000.00, "2009-09-01", 2);
        Console.WriteLine("Number of affected rows: {0}", rowsAffected);

        // Get the DepartmentTest object. 
        DepartmentInfo department = context.ExecuteStoreQuery<DepartmentInfo>
            ("select * from Department where DepartmentID= {0}", DepartmentID).FirstOrDefault();

        Console.WriteLine("ID: {0}, Name: {1} ", department.DepartmentID, department.Name);

        rowsAffected = context.ExecuteStoreCommand("delete from Department where DepartmentID = {0}", DepartmentID);
        Console.WriteLine("Number of affected rows: {0}", rowsAffected);
    }
}