How to use SqlCeParameterCollection?

问题

I wanna to know exactly how we do these thing on C# .NET 4.0 Form Application:

Declaring SqlCeParameterCollection Object
Adding Parameters to the collection
Add the Collection to the Command

Here are samples of my current code:

Declaring & Adding

SqlCeParameterCollection Parameters = new SqlCeCommand().Parameters;
Parameters.Add("username", Username);
Parameters.Add("password", Password);

Now how to add this collection at once to the command?

Thanks

回答1:

Try this:

string query = "...(whatever you need).....";

using(SqlCeConnection conn = new SqlCeConnection(connectionString))
using(SqlCeCommand cmd = new SqlCeCommand(query, conn))
{ 
    // just add parameters directly to SqlCeCommand object .... 
    cmd.Parameters.Add("username", Username);
    cmd.Parameters.Add("password", Password);

    conn.Open();
    cmd.ExecuteNonQuery();  // or whatever you need to do 
    conn.Close();
}

If you must set up your parameters separately, up front, then you need to do something like this (since you cannot directly use SqlCeParameterCollection):

List<SqlCeParameters> parameters = new List<SqlCeParameters>();

parameters.Add(new SqlCeParameter(.....));
parameters.Add(new SqlCeParameter(.....));

string query = "...(whatever you need).....";

using(SqlCeConnection conn = new SqlCeConnection(connectionString))
using(SqlCeCommand cmd = new SqlCeCommand(query, conn))
{ 
    // add all parameters from the list - casting to an array
    cmd.Parameters.AddRange(parameters.ToArray());

    conn.Open();
    cmd.ExecuteNonQuery();  // or whatever you need to do 
    conn.Close();
}

回答2:

SqlCeCommand.Parameters is read only, so you won't be able to assign a new SqlParametersCollection directly to this property.

You typically want to use the CreateCommand factory method on SqlCeConnection to create the command (as it will link the connection for you).

Then you use the command.Parameters directly:

SqlCeCommand cmd = con.CreateCommand();
// cmd.CommandType = ...; cmd.CommandText = ...
cmd.Parameters.Add("username", Username);
cmd.Parameters.Add("password", Password);

来源：https://stackoverflow.com/questions/13062162/how-to-use-sqlceparametercollection

标签

.net

sql-server-ce