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Closed 10 years ago.
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SQL Server & .net support calling a stored procedure with param's values wihout providing param's names?
I want to call a command.ExecuteReader() of type Stored Procedure, however I do not want the parameter names that I pass to be identical to the ones in the SP. Below is a sample of what I'm trying to do
SP:
ALTER PROCEDURE SPName
#Id nvarchar(50)
AS
BEGIN
SET NOCOUNT ON;
SELECT * FROM TableName
WHERE ColumnName = #Id
END
GO
Code:
using (SqlCommand command = new SqlCommand(spName, connection) { CommandType = CommandType.StoredProcedure })
{
command.parameters.Add(new SqlParameter(*paramaeter name*, sqlDbType.nvarchar){ Value = "SomeValue"};
}
If you want a generic style function, without needing an extra round-trip, and you're happy to use reflection you could use something like this.
// Return an array of SqlParameter's by using reflection on ParamObject
private static SqlParameter[] GetParametersFromObject( object ParamObject )
{
var Params = new List<SqlParameter>();
foreach( var PropInfo in ParamObject.GetType().GetProperties() )
{
Params.Add( new SqlParameter( PropInfo.Name, PropInfo.GetValue( ParamObject, null ) ) );
}
return Params.ToArray();
}
public static void ExecuteSP( SqlConnection Connection, string SPName, object ParamObject )
{
using( var Command = new SqlCommand() )
{
Command.Connection = Connection;
Command.CommandType = CommandType.StoredProcedure;
Command.CommandText = SPName;
Command.Parameters.AddRange( GetParametersFromObject( ParamObject ) );
// Command.ExecuteReader()...
}
}
This uses reflection to get the property names and values out of the anonymous object to populate the SqlCommand. This can be used as such;
ExecuteSP( Conn, "GetStuff", new { Id = 7, Name = "Test" } );
This way ExecuteSP is 'generic' and you pick the parameter names and values when you call ExecuteSP.
Simple fact - you ultimately have to use the correct parameter name when calling a stored procedure because SQL server binds parameters by name (even when you use EXEC to call an SP without using named parameters, the parser binds them by name from left to right).
So if you want to use a different name you will need to introduce an intermediate layer between your SqlCommand and the target SP.
But if you just want to not care about the name and have it automatically discovered - then you can use the technique mentioned by Conrad Frix in his accepted answer on SQL Server & .net support calling a stored procedure with param's values wihout providing param's names? - which is why I've marked as a duplicate, because it is ultimately what you want to do, even if the reasons are different.
For SqlServer there is a DeriveParameters method that takes a command object and queries the database for the parameters (names and types) of the requested stored procedure.
You can then iterate over them and supply values.
Note: this means an extra trip to the database, so if you need this often, you might want to cache the results.
The method below allows you to write generic code for calling stored procedures, but also gives you the flexibility to perform specific actions for each different stored procedure
public delegate void SqlCOmmandDelegate(SqlCommand command);
public class Dal
{
public void ExecuteStoredProcedure(string procedureName,
SqlCommandDelgate commandDelegate)
{
using (SqlConnection connection = new SqlConnection())
{
connection.ConnectionString = GetConnectionString();
using (SqlCommand command = connection.CreateCommand())
{
command.CommandType = CommandType.StoredProcedure;
command.CommandText = procedureName;
connection.Open();
commandDelegate(command);
}
}
}
}
class UsesDal
{
public CallFirstProcedure(int value)
{
string userName;
ExecuteStoredProcedure("FIRST_PROCEDURE",
delegate(SqlCommand command)
{
command.Parameters.Add("UserID", value);
command.ExecuteReader();
//Do stuff with results e.g.
username = command.Parameters.Parameters["UserName"].ToString();
}
}
public CallOtherProcedure(string value)
{
int id;
ExecuteStoredProcedure("OTHER_PROCEDURE",
delegate(SqlCommand command)
{
command.Parameters.Add("ParameterName", value);
id = command.ExecuteScalar();
}
}
}
Related
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Pass Array Parameter in SqlCommand
(11 answers)
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For some reason the Sqlparameter for my IN() clause is not working. The code compiles fine, and the query works if I substitute the parameter with the actual values
StringBuilder sb = new StringBuilder();
foreach (User user in UserList)
{
sb.Append(user.UserId + ",");
}
string userIds = sb.ToString();
userIds = userIds.TrimEnd(new char[] { ',' });
SELECT userId, username
FROM Users
WHERE userId IN (#UserIds)
You have to create one parameter for each value that you want in the IN clause.
The SQL needs to look like this:
SELECT userId, username
FROM Users
WHERE userId IN (#UserId1, #UserId2, #UserId3, ...)
So you need to create the parameters and the IN clause in the foreach loop.
Something like this (out of my head, untested):
StringBuilder sb = new StringBuilder();
int i = 1;
foreach (User user in UserList)
{
// IN clause
sb.Append("#UserId" + i.ToString() + ",");
// parameter
YourCommand.Parameters.AddWithValue("#UserId" + i.ToString(), user.UserId);
i++;
}
Possible "cleaner" version:
StringBuilder B = new StringBuilder();
for (int i = 0; i < UserList.Count; i++)
YourCommand.Parameters.AddWithValue($"#UserId{i}", UserList[i].UserId);
B.Append(String.Join(",", YourCommand.Parameters.Select(x => x.Name)));
If you are using SQL 2008, you can create a stored procedure which accepts a Table Valued Parameter (TVP) and use ADO.net to execute the stored procedure and pass a datatable to it:
First, you need to create the Type in SQL server:
CREATE TYPE [dbo].[udt_UserId] AS TABLE(
[UserId] [int] NULL
)
Then, you need to write a stored procedure which accepts this type as a parameter:
CREATE PROCEDURE [dbo].[usp_DoSomethingWithTableTypedParameter]
(
#UserIdList udt_UserId READONLY
)
AS
BEGIN
SELECT userId, username
FROM Users
WHERE userId IN (SELECT UserId FROM #UserIDList)
END
Now from .net, you cannot use LINQ since it does not support Table Valued Parameters yet; so you have to write a function which does plain old ADO.net, takes a DataTable, and passes it to the stored procedure: I've written a generic function I use which can do this for any stored procedure as long as it takes just the one table-typed parameter, regardless of what it is;
public static int ExecStoredProcWithTVP(DbConnection connection, string storedProcedureName, string tableName, string tableTypeName, DataTable dt)
{
using (SqlConnection conn = new SqlConnection(connection.ConnectionString))
{
SqlCommand cmd = new SqlCommand(storedProcedureName, conn);
cmd.CommandType = CommandType.StoredProcedure;
SqlParameter p = cmd.Parameters.AddWithValue(tableName, dt);
p.SqlDbType = SqlDbType.Structured;
p.TypeName = tableTypeName;
conn.Open();
int rowsAffected = cmd.ExecuteNonQuery(); // or could execute reader and pass a Func<T> to perform action on the datareader;
conn.Close();
return rowsAffected;
}
}
Then you can write DAL functions which use this utility function with actual names of stored procedures; to build on the example in your question, here is what the code would look like:
public int usp_DoSomethingWithTableTypedParameter(List<UserID> userIdList)
{
DataTable dt = new DataTable();
dt.Columns.Add("UserId", typeof(int));
foreach (var userId in updateList)
{
dt.Rows.Add(new object[] { userId });
}
int rowsAffected = ExecStoredProcWithTVP(Connection, "usp_DoSomethingWithTableTypedParameter", "#UserIdList", "udt_UserId", dt);
return rowsAffected;
}
Note the "connection" parameter above - I actually use this type of function in a partial DataContext class to extend LINQ DataContext with my TVP functionality, and still use the (using var context = new MyDataContext()) syntax with these methods.
This will only work if you are using SQL Server 2008 - hopefully you are and if not, this could be a great reason to upgrade! Of course in most cases and large production environments this is not that easy, but FWIW I think this is the best way of doing this if you have the technology available.
SQL Server sees your IN clause as:
IN ('a,b,c')
What it needs to look like is:
IN ('a','b','c')
There is a better way to do what you're trying to do.
If the user id's are in the DB, then the IN clause should be changed to a subquery, like so:
IN (SELECT UserID FROM someTable WHERE someConditions)
This is a hack -- it doesn't work well with indexes, and you have to be careful it works right with your data, but I've used it successfully in the past:
#UserIDs LIKE '%,' + UserID + ',%' -- also requires #UserID to begin and end with a comma
I have a stored procedure that has a parameter called UserName and in my code behind I have a SqlCommand object that I add the parameters to with the Add method. But for some reason when the command object tries to run the ExecuteReader method, it throws an exception. I am totally at a loss and have no idea why it's not recognizing the parameter. Before the ExecuteReader method is run I have a break point set so I can confirm the command object does contain the parameters being set, which is true. I know the stored procedure does return the correct data when the parameters are not added to the command object, but are hard coded in the actual stored procedure. Below is the exception message that is given in the catch block. I will also paste my code and first part of stored procedure. I would greatly appreciate any help in this issue, seeing that I have tried many different approaches to no avail. Thanks in advance.
Exception Message
Procedure or function 'someStoredProcedure' expects parameter '#UserName', which was not supplied.
Code Behind
private DataTable GetLossMitData(string code, DateTime? start, DateTime? end)
{
DataTable results = new DataTable();
string connectionString = ConfigurationManager.ConnectionStrings["asdf"].ConnectionString;
string userName = String.Empty;
try
{
using (SPSite site = new SPSite(ConfigurationManager.AppSettings["someName"]))
{
using (SPWeb web = site.OpenWeb())
{
userName = web.CurrentUser.Email.ToString();
}
}
using (SqlConnection connection1 = new SqlConnection(connectionString))
{
connection1.Open();
using (SqlCommand command1 = new SqlCommand("someStoredProcedure", connection1))
{
command1.Parameters.Add(new SqlParameter("#UserName", userName));
command1.Parameters.Add(new SqlParameter("#ProductCode", code));
SqlDataReader dr = command1.ExecuteReader(CommandBehavior.CloseConnection);
results.Load(dr);
}
connection1.Close();
}
}
catch (Exception ex)
{
}
return results;
}
Stored Procedure
#UserName nvarchar(256),
#ProductCode nvarchar(256),
#StartDate nvarchar(256) = '1/1/1900',
#EndDate nvarchar(256) = '12/30/2012'
AS
BEGIN
SET NOCOUNT ON;
Declare #UserID int
Select #UserID = Users.UserID
from Users
where Users.Email = #UserName
Try making sure that the command type is set to stored procedure.
mycommand.CommandType = System.Data.CommandType.StoredProcedure;
You will get this exception if the value of your 'userName' variable is null
If null is valid, then pass 'DBNull.Value' to the db instead:
command1.Parameters.Add(new SqlParameter("#UserName", (userName ?? DBNull.Value));
Command1.CommandType = System.Data.CommandType.StoredProcedure
This will force the ExecuteReader to perform the exec instead of just trying it as a flat command.
By default, the CommandText property needs to contain a complete SQL command, not just the name of the stored procedure.
You can change this by to set the SqlCommand's CommandType property to StoredProcedure.
Alternatively, you could explicitly pass the parameters, by changing the CommandText to "someStoredProcedure #UserName, #ProductCode"; this is a complete SQL statement and will work with the default CommandType of Text.
EDIT: I just tried it, and the only way to get that error message without setting CommandType to StoredProcedure (which he did not do) is if CommandText is EXEC someStoredProcedure. Passing a null parameter gives a different error.
I have a web service in C#, I use it to consults from tables, but I want to create a WebMethod to call a stored procedure and get back multiples output parameters. I can execute it with output parameters, it doesn't work when I try to call it whit outputs parameters.
This is a sample, I want to get back more that 2 parameters.
Stored procedure:
CREATE OR REPLACE PROCEDURE O_CAPEREZ.GIO_SP (
VNOMBRE IN VARCHAR2,
SALUDO OUT VARCHAR2 )
AS
BEGIN
INSERT INTO G_PRUEBA_SP(NOMBRE)
VALUES (vNOMBRE);
SALUDO:= ('Hello: ' || vNOMBRE);
END;
And this is my code in the web service, when I execute it using output variables I get this error
[HYC00] [Oracle][ODBC]Optional feature not implemented
C# code:
[WebMethod]
public string AP_Data(string curp)
{
string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
using (OdbcConnection con = new OdbcConnection(constr))
{
OdbcCommand cmd = new OdbcCommand("{CALL GIO_SP(?,?)}", con);
cmd.CommandType = System.Data.CommandType.StoredProcedure;
cmd.Parameters.AddWithValue("#vNOMBRE", (curp));
cmd.Parameters.Add("#vNOMBRE", OdbcType.VarChar, 18);
cmd.Connection.Open();
cmd.ExecuteNonQuery();
cmd.Parameters["#SALUDO"].Direction = ParameterDirection.ReturnValue;
cmd.Connection.Close();
string ret = Convert.ToString(cmd.Parameters["#SALUDO"].Value);
return ret;
}
}
You have to add the parameter to the list even if you're not going to set a value there:
cmd.Parameters.Add("#SALUDO", OdbcType.VarChar, 18).Direction = ParameterDirection.Output;
I don't know the the Oracle flavor is different, but in SQL I use ParameterDirection.ReturnValue rather than ParameterDirection.Output.
here's how i do it in MS SQL server 2008 But notice the data type and the lenth of the variables your create must be the same in your table
the stored proc create code
USE DATABASE DATABASE_NAME
GO
CREATE PROC SP_METHOD
#ID_CATIGORY INT,
#NAME VARCHAR (50),
#DESCRIPTION VARCHAR (50)
AS
INSERT INTO TABLE_NAME
([ID_CAT]
,[NAME_PRODUCT]
,[DESC_PRODUCT]
)
VALUES
( #ID_CATIGORY
,#NAME
,#DESCRIPTION )
GO
in the c# code
// Create SqlConnection
SqlConnection conn= new SqlConnection(#"Server=server_name;
DataBase=your_data_base_name;Integrated Security=false;User
Id=user_id;Password=password");
// Open the Connection
if (sqlconnection.State != ConnectionState.Open)
{
conn= .Open();
}
// execute stored_procedure method don't change this
public void ExecuteCommand(string stored_procedure, SqlParameter[] param)
{
SqlCommand sqlcomd = new SqlCommand();
sqlcomd.CommandType = CommandType.StoredProcedure;
sqlcomd.CommandText = stored_procedure;
sqlcomd.Connection = sqlconnection;
if (param !=null)
{
sqlcomd.Parameters.AddRange(param);
}
sqlcomd.ExecuteNonQuery();
}
// close connection method
public void close_conn()
{
if (sqlconnection.State == ConnectionState.Open)
{
sqlconnection.Close();
}
}
// execute and retrieving data Method
public void Add_product(int ID_cat ,string Name_Product,string
Des_Product)
{
SqlParameter[] param = new SqlParameter[3];
param[0] = new SqlParameter("#ID_CAT", SqlDbType.Int);
param[0].Value = ID_cat;
param[1] = new SqlParameter("#NAME_PRODUCT", SqlDbType.VarChar, 50);
param[1].Value = Name_Product;
param[2] = new SqlParameter("#DESC_PRODUCT", SqlDbType.VarChar, 50);
param[2].Value = Des_Product;
ExecuteCommand("StoredProcedure_name", param);
close_conn();
}
and finally you can call this function
Add_product(Convert.ToInt32(ComboBox.SelectedValue),txt_name.Text,
txt_desc.Text);
if there is any part you don't understand lemme know
I've seen many ways to accomplish this.
One way is to Pipe Delimit your select statement in your stored procedure and then use "Value1|Value2".Split('|')[0] to get Value1.
You could also return a table instead of using multiple parameters
DataTable table = new DataTable();
DataAdapter adapter = new DataAdapter(cmd);
adapter.fill(table);
return table.Rows[0]["Greeting"] + table.Rows[0]["Name"];
In the second example you can return as many 'Parameters' as you want, but you will have to assign them to their rightful spots later in your code.
I've also seen an XML way to do this same feature but I won't provide the code here since I don't personally think it is a very good way to do it. The way I've seen done was adding a bunch of XML attributes to a parent tag, and then coming back later and finding the value of each tag later in the code.
In MYSQL it would go like this
CREATE PROCEDURE O_CAPEREZ.GIO_SP (
#vNOMBRE VARCHAR(50))
AS
BEGIN
INSERT INTO G_PRUEBA_SP(NOMBRE)
VALUES (#vNOMBRE);
select 'Hola' as Greeting, #vNOMBRE as Name
END
Also note what Marc_s commented
You need to set the .Direction of the parameter BEFORE making the call to .ExecuteNonQuery()
Attempted (non-working) solution included below.
I have an sql function called get_parameter which looks in a table for a given string and returns the associated string:
declare #str varchar(20);
set #str = dbo.get_parameter('filecount')
print #str
It works! I run this and it prints out exactly what it should print. In this case, the parameter is the string '44'.
Now I want to run a C# CLR. But I want the CLR to be able to look up the parameter that it needs.
[SqlFunction(DataAccess = DataAccessKind.Read)]
public static string Import_TestFunc()
{
using (SqlConnection conn = new SqlConnection("context connection=true"))
{
SqlCommand command = new SqlCommand();
command.Connection = conn;
conn.Open();
// Find out how many files DSAMS processing requires.
command.CommandText = #"EXEC get_parameter 'filecount' ";
string cnt = (string)command.ExecuteScalar();
if (String.IsNullOrEmpty(cnt))
{
return "'cnt' not found."; // error return code. can't find this parameter.
}
return cnt;
}
}
However, this does not work. It constantly thinks the value for cnt is null (or empty) when it returns from get_parameter.
As requested, the code for get_parameter
ALTER FUNCTION [dbo].[get_parameter]
(
#SelectedParameterName nvarchar(max)
)
RETURNS nvarchar(max)
AS
BEGIN
DECLARE #result nvarchar(max);
SET #result = (SELECT ParameterValue from Parameters WHERE ParameterName = #SelectedParameterName);
RETURN isnull(#result,'');
END
I have tried the solution as per Mike Dinescu below, but it problem is that the call to ExecuteScalar() still returns a null. I did try to change to CommandType.Text and in that case I get the following interesting message:
A .NET Framework error occurred during execution of user-defined routine or aggregate "Import_TestFunc":
System.Data.SqlClient.SqlException: Procedure or function 'get_parameter' expects parameter '#SelectedParameterName', which was not supplied.
This is interesting, because I'm looking right at where it adds the parameter #SelectedParameterName.
command.Parameters.Add(new SqlParameter("#SelectedParameterName", SqlDbType.NVarChar )).Value = "filecount";
If you want to execute a user-defined function, or stored procedure from .NET, you should set the CommandType to CommandType.StoredProcedure, and add the needed parameters to the command object before executing the command.
command.CommandType = CommandType.StoredProcedure;
command.CommandText = #"dbo.get_parameter";
// here you add the paramters needed for your procedure/function
// in your case it will be just one (make sure you add the correct name for you function)
command.Parameters.Add(new SqlParamter("SelectedParameterName", SqlDbType.NVarChar));
command.Prepare();
command.Parameters[0].Value = "filecount";
string cnt = (string)command.ExecuteScalar();
How do i pass a stored procedure with parameters to a function.
I actually have a function to insert data into database..
im looking for a way where i could pass the SP with parameters to that
insert function so as to reuse the insert data code.
Put the call to the stored procedure in a method and call this method from anywhere you want to call it. Pass parameters (strings, ints, doubles, ...) to this method and put these values in the stored procedure's parameters.
This way you keep all the SP code in one place.
public class CustomerProvider
{
public int UpdateCustomer(int id, string name, string address)
{
using(connection = new
SqlConnection("Server=localhost;DataBase=Northwind;Integrated Security=SSPI"))
{
connection.Open();
var command = new SQLCommand("csp_updatecustomer", connection);
command.CommandType = CommandType.StoredProcedure;
command.Parameters.Add(
new SqlParameter("#CustomerID", id));
command.Parameters.Add(
new SqlParameter("#CustomerName", name));
command.Parameters.Add(
new SqlParameter("#CustomerAddress", address));
var result = command.ExecuteNonQuery();
return result;
}
}
}