Develop Reference

Which method of the SqlCommand is more preferable when i need to get only out params?

I'm asking about only sync methods of the SqlCommand class.
There are three methods (as everyone know) - ExecuteReader(), ExecuteScalar() and ExecuteNonQuery().
Which kind of this methods is more suitable for stored procedure likes this :
CREATE PROCEDURE [dbo].[pr_test]
#partherId UNIQUEIDENTIFIER,
#lowerBound SMALLINT = -1 out,
#upperBound SMALLINT = -1 out
AS
BEGIN
SET NOCOUNT ON;
SELECT
#lowerBound = ISNULL(MIN(SrartDayNumber), -1)
,#upperBound = ISNULL(MAX(EndDayNumber), -1)
FROM [CpsOther].[dbo].[FinDocument] f
WHERE f.partherId = #partherId
END
I need only out params and nothing else. I don't know which method of the SqlCommand is more suitable in this situation? Or it's doesn't matter. (The results are same)
int lowerBound = -1;
int upperBound = -1;
using (SqlConnection connection = new SqlConnection(_connectionString))
{
using (SqlCommand command = new SqlCommand())
{
command.Connection = connection;
command.CommandType = CommandType.StoredProcedure;
command.CommandText = "[dbo].[pr_test]";
SqlParameter lowerBoundParam = new SqlParameter
{
ParameterName = "#lowerBound",
Value = lowerBound,
Direction = ParameterDirection.Output
};
SqlParameter upperBoundParam = new SqlParameter
{
ParameterName = "#upperBound",
Value = upperBound,
Direction = ParameterDirection.Output
};
command.Parameters.AddWithValue("#partnerId", Guid.Empty);
command.Parameters.Add(lowerBoundParam);
command.Parameters.Add(upperBoundParam);
connection.Open();
object result = command.ExecuteScalar();
//or object result = command.ExecuteNonQuery();
lowerBound = lowerBoundParam.Value as int? ?? -1;
lowerBound = lowerBoundParam.Value as int? ?? -1;
}
}

ExecuteNonQuery is the better solution for this. The other two are for commands that return a rowset.
To elaborate:
ExecuteReader is for situations where you want to iterate over a set of rows being returned by the command.
ExecuteScalar is for situations where you want to receive the first column of the first row being returned. It will automatically discard all other row data.
ExecuteNonQuery is for commands that do not return rowsets directly.
They all have the same abilities as regards parameters with directions of Output, InputOutput or ReturnValue. The only difference is how they deal with rowsets.

Conversion failed when converting the varchar value

When I try to run this, it gives me the following error message:
Conversion failed when converting the varchar value 'category_id' to data type int.
Here's my SQL and parameter code, I supposed it should work, but it doesn't.
mycmd.CommandText="SELECT * FROM categories WHERE #db_property = #property_id";
// This contains a string "category_id", which is correct.
mycmd.Parameters.Add("#db_property", SqlDbType.VarChar).Value=db_property_field;
// This contains an Int, referring to the category_id in database. As of now, this is 1
mycmd.Parameters.Add("#property_id", SqlDbType.Int).Value=property_id;
After I'm going through this code, I run it through a Reader, and that's where I get the error message above. Been asking teacher, and excellent students in my class, no one can find a clue on, where the problem is.

You shouldn't add field name as parameter. Try to change your script to include actual field id:
mycmd.CommandText = "SELECT * FROM categories WHERE category_id = #property_id";
mycmd.Parameters.Add("#property_id", SqlDbType.Int).Value = property_id;

I'm not sure about your structure, but try the following:
mycmd.CommandText = "SELECT * FROM categories WHERE Cast(#db_property as Int) = #property_id";

Your query is matching the two variables you are passing in so it will either return all the data or none of it! On top of that you are matching a char variable with an int. SQL will try to cast the char variable to an int.
#db_property = #property_id
should your query look like this?
SELECT * FROM categories WHERE db_property = #db_property AND property_id = #property_id

If you look at your statement you are comparing the two parameters. The WHERE clause is not on a table column ("categories") and the two parameters you are passing are different data types. VarChar and Int. When that command is executed the SQL engine is trying to compare two variables of different data types.
If you run the following SQL statements straight against SQL you will receive the same error.
DECLARE #Var1 VARCHAR(100)
DECLARE #Var2 INT
SELECT #Var1 = 'Test', #Var2 = 1
SELECT * FROM dbo.categories WHERE #Var1 = #Var2

You can get solution from the following address:
http://net-informations.com/csprj/data-providers/cs-procedure-parameter.htm
For your information I Just reshape the code and use it to my needs.
Code of Stored Procedure is as follow:
Create PROCEDURE [dbo].[PmSPValidate]
#a varchar(10)
AS
BEGIN
(SELECT AcctDsc,AcctAge
FROM dbo.tblCoa
WHERE AcctNo >= #a)
END
Code of C# :
private void btnThirdTrial_Click(object sender, EventArgs e)
{
string connetionString = null;
SqlConnection connection;
SqlDataAdapter adapter;
SqlCommand command = new SqlCommand();
SqlParameter param;
DataSet ds = new DataSet();
int i = 0;
connetionString = "Data Source=FIN03;Initial Catalog=CmsTest;Integrated Security=True";
connection = new SqlConnection(connetionString);
connection.Open();
command.Connection = connection;
command.CommandType = CommandType.StoredProcedure;
command.CommandText = "dbo.PmSPValidate";
param = new SqlParameter("#a",Account.Text.ToString ());
param.Direction = ParameterDirection.Input;
param.DbType = DbType.String;
command.Parameters.Add(param);
adapter = new SqlDataAdapter(command);
adapter.Fill(ds);
for (i = 0; i <= ds.Tables[0].Rows.Count - 1; i++)
{
MessageBox.Show(" Name " + ds.Tables[0].Rows[i][0].ToString() + " Age " + ds.Tables[0].Rows[i][1].ToString());
}
connection.Close();
}

Return an sql variable's value from within an Oracle Sql Query back to .NET code

For the past few hours I am trying to do the simplest of the simple things (at least for SQL SERVER) in an Oracle Data Base, through a .NET application using ADO.NET. It seems impossible.
For SQL SERVER I would do this simple task, supposing I have an SqlCommand object
comm.CommandText = #"
DECLARE #next_id INT
SET #next_id = (SELECT ISNULL(MAX(id_col),0) FROM TABLE_1) + 1
INSERT INTO TABLE_1 (id_col, col1, ...) VALUES (#next_id, val1, ...)
SELECT #next_id";
int id = Convert.ToInt32(comm.ExecuteScalar());
That would insert a new record to table TABLE_1 and I would take back the new id in the "id" variable in c# code.
Four simple steps
Declare a variable
Set it to the next available id
Insert the record with the new variable
Return the variable's value
Ok I managed to declare the variable in Oracle query. Also I (think) I managed to give it a value (With SELECT INTO)
How can I get back this variable's value back in c#? How can i SELECT a variable's value to the output stream in Oracle SQL?
I know that there are better ways to achieve getting back an identity column, but that's not the question here. It could be a totally different example. The question is simple.: I have declared a variable inside an oracle sql script that will be executed from within .net app. How can i get the variable's value back to c#, from an oracle query? What is the above code's equivalent with Oracle ADO.NET query?

You'll want to use ODP.NET (Oracle's Oracle Data Access Components):
An example of this is below. Note that in ODP.NET, you can establish a parameters direction (input, inputoutput, output, returnvalue) to correspond with the parameters of the procedure or statement you're running. In this example, I'm grabbing a returnvalue, which is an ID that is generated by the db via a sequence and trigger (its created automagically as far as the .NET app is concerned):
int event_id = 0;
using (OracleConnection oraConn = new OracleConnection(connStr))
{
string cmdText = #"insert into EVENT
(EVENT_NAME, EVENT_DESC)
values
(:EVENT_NAME, :EVENT_DESC)
RETURNING EVENT_ID INTO :EVENT_ID
";
using (OracleCommand cmd = new OracleCommand(cmdText, oraConn))
{
oraConn.Open();
OracleTransaction trans = oraConn.BeginTransaction();
try
{
OracleParameter prm = new OracleParameter();
cmd.BindByName = true;
prm = new OracleParameter("EVENT_NAME", OracleDbType.Varchar2);
prm.Value = "SOME NAME"; cmd.Parameters.Add(prm);
prm = new OracleParameter("EVENT_DESC", OracleDbType.Varchar2);
prm.Value = "SOME DESC"; cmd.Parameters.Add(prm);
prm = new OracleParameter( "EVENT_ID"
, OracleDbType.Int32
, ParameterDirection.ReturnValue);
cmd.Parameters.Add(prm);
cmd.ExecuteNonQuery();
trans.Commit();
// return value
event_id = ConvertFromDB<int>(cmd.Parameters["EVENT_ID"].Value);
}
catch
{
trans.Rollback();
throw;
}
finally
{
trans.Dispose();
}
oraConn.Close();
}
}
The ConvertFromDB is just a generic to cast the return value to its .NET equivalent (an int in this case).
Hope that helps.
EDIT:
You can easily bind an array of values (and retrieve an array of return values) in ODP.NET:
using (OracleConnection oraConn = new OracleConnection(connStr))
{
string cmdText = #"insert into TEST_EVENT
(EVENT_NAME, EVENT_DESC)
values
(:EVENT_NAME, :EVENT_DESC)
RETURNING EVENT_ID INTO :EVENT_ID
";
using (OracleCommand cmd = new OracleCommand(cmdText, oraConn))
{
oraConn.Open();
OracleTransaction trans = oraConn.BeginTransaction();
try
{
string[] event_names = new string[2];
string[] event_descs = new string[2];
int[] event_ids = new int[2];
event_names[0] = "Event1";
event_descs[0] = "Desc1";
event_names[1] = "Event2";
event_descs[1] = "Desc2";
OracleParameter prm = new OracleParameter();
cmd.Parameters.Clear();
cmd.ArrayBindCount = 2;
cmd.BindByName = true;
prm = new OracleParameter("EVENT_NAME", OracleDbType.Varchar2);
prm.Value = event_names; cmd.Parameters.Add(prm);
prm = new OracleParameter("EVENT_DESC", OracleDbType.Varchar2);
prm.Value = event_descs; cmd.Parameters.Add(prm);
prm = new OracleParameter( "EVENT_ID"
, OracleDbType.Int32
, ParameterDirection.ReturnValue);
cmd.Parameters.Add(prm);
cmd.ExecuteNonQuery();
trans.Commit();
// get return values
event_ids = (int[])(cmd.Parameters["EVENT_ID"].Value);
}
catch
{
trans.Rollback();
throw;
}
finally
{
trans.Dispose();
}
oraConn.Close();
}
}

When is a String not a String

From the "Things that go bump in the database engine" department:
This function returns what looks like a valid value, but the record is not posted (no err msg):
private String GetInterpreterTicketIDSequenceVal()
{
con = new OracleConnection(oradb);
con.Open();
String query = "SELECT TO_CHAR(SYSDATE,'YYYYMMDD-') || LTRIM(TO_CHAR(ABC.SOMETABLEID.NEXTVAL, '000000')) FROM DUAL";
cmd = new OracleCommand(query, con);
cmd.CommandType = CommandType.Text;
//MessageBox.Show(cmd.ExecuteScalar().ToString());
return cmd.ExecuteScalar().ToString();
}
...SEEMS to work (returns a value, and the insertion is (seemingly) made without squawking)... yet, no record is inserted into the database.
This kludgy (sp?) function, OTOH:
private String GetSomeTableIDSequenceVal_Fake()
{
int iYear = DateTime.Now.Year;
int iMonth = DateTime.Now.Month;
int iDay = DateTime.Now.Day;
int iHour = DateTime.Now.Hour;
int iSecond = DateTime.Now.Second;
String sYear = iYear.ToString();
String sMonth = iMonth.ToString();
String sDay = iDay.ToString();
String sHour = iHour.ToString();
String sSecond = iSecond.ToString();
if (iMonth < 10)
{
sMonth = String.Format("0{0}", sMonth);
}
if (iDay < 10)
{
sDay = String.Format("0{0}", sDay);
}
if (iHour < 10)
{
sHour = String.Format("0{0}", sHour);
}
if (iSecond < 10)
{
sSecond = String.Format("0{0}", sSecond);
}
return String.Format("{0}{1}{2}-{3}{4}", sYear, sMonth, sDay, sHour, sSecond);
}
...works fine - the record is inserted into the database (the code that calls these functions follows).
It seems odd that they both return a string, yet one works, and one doesn't... that column doesn't have a constraint on it that is rejecting the value from the former function, so…???
Anyway, here’s the code that calls either of those functions, in context:
try
{
con = new OracleConnection(oradb);
con.Open();
String query = "INSERT INTO ABC.SOMETABLE (TICKETID, TICKETSOURCE, ABOUTSOMEID, CATEGORYID, CONTACTEMAIL) VALUES (:p_TICKETID, :p_TICKETSOURCE, :p_ABOUTSOMEID, :p_CATEGORYID, :p_CONTACTEMAIL)";
cmd = new OracleCommand(query, con);
cmd.CommandType = CommandType.Text;
// Params = TICKETID, TICKETSOURCE, ABOUTSOMEID, CATEGORYID, CONTACTEMAIL
OracleParameter p_TICKETID = new OracleParameter();
p_TICKETID.Direction = ParameterDirection.Input;
p_TICKETID.OracleDbType = OracleDbType.NVarchar2;
p_TICKETID.Size = 20;
// This doesn't allow the record to be inserted...???
//p_TICKETID.Value = GetSomeTableIDSequenceVal();
// ...but when I "fake it" below, the record IS inserted
//p_TICKETID.Value = GetSomeTableIDSequenceVal_Fake(); cmd.Parameters.Add(p_TICKETID);
OracleParameter p_TICKETSOURCE = new OracleParameter();
p_TICKETSOURCE.Direction = ParameterDirection.Input;
p_TICKETSOURCE.OracleDbType = OracleDbType.NVarchar2;
p_TICKETSOURCE.Size = 20;
p_TICKETSOURCE.Value = textBoxTicketSource.Text;
cmd.Parameters.Add(p_TICKETSOURCE);
OracleParameter p_ABOUTSOMEID = new OracleParameter();
p_ABOUTSOMEID.Direction = ParameterDirection.Input;
p_ABOUTSOMEID.OracleDbType = OracleDbType.Int32;
p_ABOUTSOMEID.Value = textBoxAboutSOMEID.Text;
cmd.Parameters.Add(p_ABOUTSOMEID);
OracleParameter p_CATEGORYID = new OracleParameter();
p_CATEGORYID.Direction = ParameterDirection.Input;
p_CATEGORYID.OracleDbType = OracleDbType.Int32;
p_CATEGORYID.Value = textBoxCategoryID.Text;
cmd.Parameters.Add(p_CATEGORYID);
OracleParameter p_CONTACTEMAIL = new OracleParameter();
p_CONTACTEMAIL.Direction = ParameterDirection.Input;
p_CONTACTEMAIL.OracleDbType = OracleDbType.NVarchar2;
p_CONTACTEMAIL.Size = 100;
p_CONTACTEMAIL.Value = textBoxContactEmail.Text;
cmd.Parameters.Add(p_CONTACTEMAIL);
try
{
cmd.ExecuteNonQuery();
}
catch (OracleException ex)
{
MessageBox.Show(ex.Message);
}
MessageBox.Show("Apparent success");
}
finally
{
con.Close();
con.Dispose();
}
Update:
I added Xaction support, and it seems to make no difference whatsoever:
I encased it in a Transaction, and it makes no difference:
OracleTransaction ot;
. . .
try
{
ot = con.BeginTransaction();
cmd.Transaction = ot;
cmd.ExecuteNonQuery();
ot.Commit();
}
catch (Exception ex)
{
ot.Rollback();
}
Update redux:
Luke made a good point about using two simultaneous connections; so, I changed that code to this:
private String GetInterpreterTicketIDSequenceVal()
{
String query = "SELECT TO_CHAR(SYSDATE,'YYYYMMDD-') || LTRIM(TO_CHAR(ABC.SOMETABLEID.NEXTVAL, '000000')) FROM DUAL";
OracleCommand oc = new OracleCommand(query, con);
oc.CommandType = CommandType.Text;
String s = oc.ExecuteScalar().ToString();
try
{
return s;
}
catch (OracleException ex)
{
MessageBox.Show(ex.Message);
return string.Empty;
}
}
...but still no joy in Mudville.
Update redux revisited:
I got it working; thanks everybody for your help and insight.
Actually, it had been working for awhile – my stupid query in Toad was the problem – I forgot that I was adding a slightly different value in new records than what I was querying for … so it looked like the records weren’t being added, but they really were.
tgif!

I tried running your code above and I was only able to reproduce problems with it if the INTERPRETERTICKETID sequence had gone beyond 999999. If you are having problems then there must be something that you are not telling us. For example, how is your table INTERPRETERTICKET defined? What constraints are on it? How is the sequence defined? Are there any triggers on the table?
Is there any need for your GetInterpreterTicketIDSequenceVal() method to use its own connection to the database? Can it not just use the same connection that the rest of your code does?
If your sequence INTERPRETERTICKETID has gone beyond 999999 then the TO_CHAR call will return a string of hashes:
SQL> select ltrim(to_char(999999, '000000')) from dual;
LTRIM(T
-------
999999
SQL> select ltrim(to_char(1000000, '000000')) from dual;
LTRIM(T
-------
#######
I put a PK constraint on the TICKETID column and after running your code twice, I got a constraint violation error.
EDIT:
In response to your comment, it is possible to use a trigger to populate the TICKETID column. You mentioned that your database apparently contains one such trigger, but without seeing how the trigger is defined, it's difficult to know what the problem with it could be.
I added the following trigger, and modified the C# code so that it didn't attempt to insert a value for TICKETID. I ran the C# code a few times and it seemed to work.
CREATE OR REPLACE TRIGGER INTERPRETERTICKETS_BI
BEFORE INSERT ON INTERPRETERTICKETS
FOR EACH ROW
BEGIN
SELECT TO_CHAR(SYSDATE,'YYYYMMDD-') || LTRIM(TO_CHAR(INTERPRETERTICKETID.NEXTVAL, '000000'))
INTO :new.TICKETID
FROM DUAL;
END;
/

the way you setup the parameters seems very strange since your parameter object end up without a name - try changing your code similar to this:
OracleParameter p_TICKETID = new OracleParameter("p_TICKETID", OracleDbType.NVarchar2, ParameterDirection.Input);
p_TICKETID.Size = 20;

The SqlParameter is already contained by another SqlParameterCollection - Does using() {} cheat?

While using the using() {} (sic) blocks as shown below, and assuming that cmd1 does not live beyond the scope of the first using() {} block, why should the second block throw an exception with the message
The SqlParameter is already contained by another SqlParameterCollection
Does it mean that resources and/or handles - including the parameters (SqlParameterCollection) - attached to cmd1 are not released when its destroyed at the end of the block?
using (var conn = new SqlConnection("Data Source=.;Initial Catalog=Test;Integrated Security=True"))
{
var parameters = new SqlParameter[] { new SqlParameter("#ProductId", SqlDbType.Int ) };
using(var cmd1 = new SqlCommand("SELECT ProductName FROM Products WHERE ProductId = #ProductId"))
{
foreach (var parameter in parameters)
{
cmd1.Parameters.Add(parameter);
}
// cmd1.Parameters.Clear(); // uncomment to save your skin!
}
using (var cmd2 = new SqlCommand("SELECT Review FROM ProductReviews WHERE ProductId = #ProductId"))
{
foreach (var parameter in parameters)
{
cmd2.Parameters.Add(parameter);
}
}
}
NOTE: Doing cmd1.Parameters.Clear() just before the last brace of the first using() {} block will save you from the exception (and possible embarrassment).
If you need to reproduce you can use the following scripts to create the objects:
CREATE TABLE Products
(
ProductId int IDENTITY(1,1) NOT NULL PRIMARY KEY CLUSTERED,
ProductName nvarchar(32) NOT NULL
)
GO
CREATE TABLE ProductReviews
(
ReviewId int IDENTITY(1,1) NOT NULL PRIMARY KEY CLUSTERED,
ProductId int NOT NULL,
Review nvarchar(128) NOT NULL
)
GO

I suspect that SqlParameter "knows" which command it's part of, and that that information isn't cleared when the command is disposed, but is cleared when you call command.Parameters.Clear().
Personally I think I'd avoid reusing the objects in the first place, but it's up to you :)

Adding cmd.Parameters.Clear(); after execution should be fine.

Using blocks do not ensure that an object is "destroyed", simply that the Dispose() method is called. What that actually does is up to the specific implementation and in this case it clearly does not empty the collection. The idea is to ensure that unmanaged resources that would not be cleaned up by the garbage collector are correctly disposed. As the Parameters collection is not an unmanaged resource it is not entirely suprising it is not cleared by the dispose method.

I faced this particular error because I was using the same SqlParameter objects as part of a SqlParameter collection for calling a procedure multiple times. The reason for this error IMHO is that the SqlParameter objects are associated to a particular SqlParameter Collection and you can't use the same SqlParameter objects to create a new SqlParameter collection.
So, instead of this:
var param1 = new SqlParameter{ DbType = DbType.String, ParameterName = param1,Direction = ParameterDirection.Input , Value = "" };
var param2 = new SqlParameter{ DbType = DbType.Int64, ParameterName = param2, Direction = ParameterDirection.Input , Value = 100};
SqlParameter[] sqlParameter1 = new[] { param1, param2 };
ExecuteProc(sp_name, sqlParameter1);
/*ERROR :
SqlParameter[] sqlParameter2 = new[] { param1, param2 };
ExecuteProc(sp_name, sqlParameter2);
*/
Do this:
var param3 = new SqlParameter{ DbType = DbType.String, ParameterName = param1, Direction = ParameterDirection.Input , Value = param1.Value };
var param4 = new SqlParameter{ DbType = DbType.Int64, ParameterName = param2, Direction = ParameterDirection.Input , Value = param2.Value};
SqlParameter[] sqlParameter3 = new[] { param3, param4 };
ExecuteProc(sp_name, sqlParameter3);

using defines a scope, and does the automatic call of Dispose() for which we love it.
A reference falling out of scope will not make the object itself "disappear" if another object has a reference to it, which in this case will be the case for parameters having a reference to cmd1.

I have Also got the same issue Thanks #Jon, based on that I gave example.
When I called the below function in which 2 times same sqlparameter passed. In the first database call, it was called properly, but in the second time, it was give the above error.
public Claim GetClaim(long ClaimId)
{
string command = "SELECT * FROM tblClaim "
+ " WHERE RecordStatus = 1 and ClaimId = #ClaimId and ClientId =#ClientId";
List<SqlParameter> objLSP_Proc = new List<SqlParameter>(){
new SqlParameter("#ClientId", SessionModel.ClientId),
new SqlParameter("#ClaimId", ClaimId)
};
DataTable dt = GetDataTable(command, objLSP_Proc);
if (dt.Rows.Count == 0)
{
return null;
}
List<Claim> list = TableToList(dt);
command = "SELECT * FROM tblClaimAttachment WHERE RecordStatus = 1 and ClaimId = #ClaimId and ClientId =#ClientId";
DataTable dt = GetDataTable(command, objLSP_Proc); //gives error here, after add `sqlComm.Parameters.Clear();` in GetDataTable (below) function, the error resolved.
retClaim.Attachments = new ClaimAttachs().SelectMany(command, objLSP_Proc);
return retClaim;
}
This is the common DAL function
public DataTable GetDataTable(string strSql, List<SqlParameter> parameters)
{
DataTable dt = new DataTable();
try
{
using (SqlConnection connection = this.GetConnection())
{
SqlCommand sqlComm = new SqlCommand(strSql, connection);
if (parameters != null && parameters.Count > 0)
{
sqlComm.Parameters.AddRange(parameters.ToArray());
}
using (SqlDataAdapter da = new SqlDataAdapter())
{
da.SelectCommand = sqlComm;
da.Fill(dt);
}
sqlComm.Parameters.Clear(); //this added and error resolved
}
}
catch (Exception ex)
{
throw;
}
return dt;
}

I encountered this exception because I had failed to instantiate a parameter object. I thought it was complaining about two procedures having parameters with the same name. It was complaining about the same parameter being added twice.
Dim aParm As New SqlParameter()
aParm.ParameterName = "NAR_ID" : aParm.Value = hfCurrentNAR_ID.Value
m_daNetworkAccess.UpdateCommand.Parameters.Add(aParm)
aParm = New SqlParameter
Dim tbxDriveFile As TextBox = gvNetworkFileAccess.Rows(index).FindControl("tbxDriveFolderFile")
aParm.ParameterName = "DriveFolderFile" : aParm.Value = tbxDriveFile.Text
m_daNetworkAccess.UpdateCommand.Parameters.Add(aParm)
**aParm = New SqlParameter()** <--This line was missing.
Dim aDDL As DropDownList = gvNetworkFileAccess.Rows(index).FindControl("ddlFileAccess")
aParm.ParameterName = "AccessGranted" : aParm.Value = aDDL.Text
**m_daNetworkAccess.UpdateCommand.Parameters.Add(aParm)** <-- The error occurred here.

Issue
I was executing a SQL Server stored procedure from C# when I encountered this issue:
Exception message [The SqlParameter is already contained by another SqlParameterCollection.]
Cause
I was passing 3 parameters to my stored procedure. I added the
param = command.CreateParameter();
only once altogether. I should have added this line for each parameter, it means 3 times altogether.
DbCommand command = CreateCommand(ct.SourceServer, ct.SourceInstance, ct.SourceDatabase);
command.CommandType = CommandType.StoredProcedure;
command.CommandText = "[ETL].[pGenerateScriptToCreateIndex]";
DbParameter param = command.CreateParameter();
param.ParameterName = "#IndexTypeID";
param.DbType = DbType.Int16;
param.Value = 1;
command.Parameters.Add(param);
param = command.CreateParameter(); --This is the line I was missing
param.ParameterName = "#SchemaName";
param.DbType = DbType.String;
param.Value = ct.SourceSchema;
command.Parameters.Add(param);
param = command.CreateParameter(); --This is the line I was missing
param.ParameterName = "#TableName";
param.DbType = DbType.String;
param.Value = ct.SourceDataObjectName;
command.Parameters.Add(param);
dt = ExecuteSelectCommand(command);
Solution
Adding the following line of code for each parameter
param = command.CreateParameter();

This is how I have done it!
ILease lease = (ILease)_SqlParameterCollection.InitializeLifetimeService();
if (lease.CurrentState == LeaseState.Initial)
{
lease.InitialLeaseTime = TimeSpan.FromMinutes(5);
lease.SponsorshipTimeout = TimeSpan.FromMinutes(2);
lease.RenewOnCallTime = TimeSpan.FromMinutes(2);
lease.Renew(new TimeSpan(0, 5, 0));
}

If you're using EntityFramework
I also had this same exception. In my case, I was calling SQL via a EntityFramework DBContext. The following is my code, and how I fixed it.
Broken Code
string sql = "UserReport #userID, #startDate, #endDate";
var sqlParams = new Object[]
{
new SqlParameter { ParameterName= "#userID", Value = p.UserID, SqlDbType = SqlDbType.Int, IsNullable = true }
,new SqlParameter { ParameterName= "#startDate", Value = p.StartDate, SqlDbType = SqlDbType.DateTime, IsNullable = true }
,new SqlParameter { ParameterName= "#endDate", Value = p.EndDate, SqlDbType = SqlDbType.DateTime, IsNullable = true }
};
IEnumerable<T> rows = ctx.Database.SqlQuery<T>(sql,parameters);
foreach(var row in rows) {
// do something
}
// the following call to .Count() is what triggers the exception
if (rows.Count() == 0) {
// tell user there are no rows
}
Note: the above call to SqlQuery<T>() actually returns a DbRawSqlQuery<T>, which implements IEnumerable
Why does calling .Count() throw the exception?
I haven't fired up SQL Profiler to confirm, but I suspect that .Count() is triggering another call to SQL Server, and internally it is reusing the same SQLCommand object and trying to re-add the duplicate parameters.
Solution / Working Code
I added a counter inside my foreach, so that I could keep a row count without having to call .Count()
int rowCount = 0;
foreach(var row in rows) {
rowCount++
// do something
}
if (rowCount == 0) {
// tell user there are no rows
}
Afterthough
My project is probably using an old version of EF. The newer version may have fixed this internal bug by clearing the parameters, or disposing of the SqlCommand object.
Or maybe, there are explicit instructions that tell developers not to call .Count() after iterating a DbRawSqlQuery, and I'm coding it wrong.