Send DataSet Sample

 

Applies To: SQL Server 2016 Preview

The Send DataSet sample demonstrates how to return an ADO.NET based DataSet within a server side common language runtime (CLR)-based stored procedure as a result set to the client. This is useful, for example, when such a stored procedure fills a DataSet using the results of a query, and then manipulates the data that is contained in that DataSet. Alternatively this is useful if the stored procedure creates and populates a DataSet from scratch.The sample is composed of two classes, DataSetUtilities and TestSendDataSet. The method SendDataSet on the DataSetUtilities class implements a general-purpose way to transmit the contents of a DataSet instance to the client. The DoTest method that is defined on the TestSendDataSet class verifies that the SendDataSet method works by creating a DataSet and filling it with data from the uspGetTwoBOMTestData Transact-SQL stored procedure. The uspGetTwoBOMTestData runs the Transact-SQL stored procedure uspGetBillOfMaterials twice to recursively query for the bill of materials for two products specified as parameters to the usp_GetTwoBOMTestData stored procedure. Ordinarily, after filling the data set, the data would be modified before invoking SendDataSet to deliver the data within the data set as a result set to the client. For simplicity, this sample returns the data without modification.

Prerequisites

To create and run this project the following the following software must be installed:

  • SQL Server or SQL Server Express. You can obtain SQL Server Express free of charge from the SQL Server Express Documentation and Samples Web site

  • The AdventureWorks database that is available at the SQL Server Developer Web site

  • .NET Framework SDK 2.0 or later or Microsoft Visual Studio 2005 or later. You can obtain .NET Framework SDK free of charge.

  • In addition, the following conditions must be met:

  • The SQL Server instance you are using must have CLR integration enabled.

  • In order to enable CLR integration, perform the following steps:

    Enabling CLR Integration

    • Execute the following Transact-SQL commands:

    sp_configure 'clr enabled', 1

    GO

    RECONFIGURE

    GO

    Note

    To enable CLR, you must have ALTER SETTINGS server level permission, which is implicitly held by members of the sysadmin and serveradmin fixed server roles.

  • The AdventureWorks database must be installed on the SQL Server instance you are using.

  • If you are not an administrator for the SQL Server instance you are using, you must have an administrator grant you CreateAssembly permission to complete the installation.

Building the Sample

Create and run the sample by using the following instructions:

  1. Open a Visual Studio or .NET Framework command prompt.

  2. If necessary, create a directory for your sample. For this example, we will use C:\MySample.

  3. In c:\MySample, create SendDataSet.vb (for the Visual Basic sample) or SendDataSet.cs (for the C# sample) and copy the appropriate Visual Basic or C# sample code (below) into the file.

  4. Compile the sample code into the required assembly from the command line prompt by executing one of the following, depending on your choice of language.

    • Vbc /reference:C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.Data.dll,C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.dll,C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.Xml.dll /target:library SendDataSet.vb

    • Csc /reference:C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.Data.dll /reference:C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.dll /reference:C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.Xml.dll /target:library SendDataSet.cs

  5. Copy the Transact-SQL installation code into a file and save it as Install.sql in the sample directory.

  6. If the sample is installed in a directory other then C:\MySample\, edit the file Install.sql as indicated to point to that location.

  7. Deploy the assembly, stored procedure and functions by executing

    • sqlcmd -E -I -i install.sql
  8. Copy the Transact-SQL test script into a file and save it as test.sql in the sample directory.

    • sqlcmd -E -I -i test.sql
  9. Copy the Transact-SQL cleanup script into a file and save it as cleanup.sql in the sample directory.

  10. Execute the script with the following command

    • sqlcmd -E -I -i cleanup.sql

Sample Code

The following are the code listings for this sample.

C#

using System;
using System.Collections.Generic;
using System.Text;
using System.Data;
using System.Data.SqlClient;
using System.Data.SqlTypes;
using Microsoft.SqlServer.Server;


    public static class DataSetUtilities
    {

        public static void SendDataSet(DataSet ds)
        {
            if (ds == null)
            {
                throw new ArgumentException("SendDataSet requires a non-null data set.");
            }
            else
            {
                foreach (DataTable dt in ds.Tables)
                {
                    SendDataTable(dt);
                }
            }
        }


        public static void SendDataTable(DataTable dt)
        {
            bool[] coerceToString;  // Do we need to coerce this column to string?
            SqlMetaData[] metaData = ExtractDataTableColumnMetaData(dt, out coerceToString);

            SqlDataRecord record = new SqlDataRecord(metaData);
            SqlPipe pipe = SqlContext.Pipe;
            pipe.SendResultsStart(record);
            try
            {
                foreach (DataRow row in dt.Rows)
                {
                    for (int index = 0; index < record.FieldCount; index++)
                    {
                        object value = row[index];
                        if (null != value && coerceToString[index])
                            value = value.ToString();
                        record.SetValue(index, value);
                    }

                    pipe.SendResultsRow(record);
                }
            }
            finally
            {
                pipe.SendResultsEnd();
            }
        }

        private static SqlMetaData[] ExtractDataTableColumnMetaData(DataTable dt, out bool[] coerceToString)
        {
            SqlMetaData[] metaDataResult = new SqlMetaData[dt.Columns.Count];
            coerceToString = new bool[dt.Columns.Count];
            for (int index = 0; index < dt.Columns.Count; index++)
            {
                DataColumn column = dt.Columns[index];
                metaDataResult[index] = SqlMetaDataFromColumn(column, out coerceToString[index]);
            }

            return metaDataResult;
        }

        private static Exception InvalidDataTypeCode(TypeCode code)
        {
            return new ArgumentException("Invalid type: " + code);
        }

        private static Exception UnknownDataType(Type clrType)
        {
            return new ArgumentException("Unknown type: " + clrType);
        }

        private static SqlMetaData SqlMetaDataFromColumn(DataColumn column, out bool coerceToString)
        {
            coerceToString = false;
            SqlMetaData sql_md = null;
            Type clrType = column.DataType;
            string name = column.ColumnName;
            switch (Type.GetTypeCode(clrType))
            {
                case TypeCode.Boolean: sql_md = new SqlMetaData(name, SqlDbType.Bit); break;
                case TypeCode.Byte: sql_md = new SqlMetaData(name, SqlDbType.TinyInt); break;
                case TypeCode.Char: sql_md = new SqlMetaData(name, SqlDbType.NVarChar, 1); break;
                case TypeCode.DateTime: sql_md = new SqlMetaData(name, SqlDbType.DateTime); break;
                case TypeCode.DBNull: throw InvalidDataTypeCode(TypeCode.DBNull);
                case TypeCode.Decimal: sql_md = new SqlMetaData(name, SqlDbType.Decimal, 18, 0); break;
                case TypeCode.Double: sql_md = new SqlMetaData(name, SqlDbType.Float); break;
                case TypeCode.Empty: throw InvalidDataTypeCode(TypeCode.Empty);
                case TypeCode.Int16: sql_md = new SqlMetaData(name, SqlDbType.SmallInt); break;
                case TypeCode.Int32: sql_md = new SqlMetaData(name, SqlDbType.Int); break;
                case TypeCode.Int64: sql_md = new SqlMetaData(name, SqlDbType.BigInt); break;
                case TypeCode.SByte: throw InvalidDataTypeCode(TypeCode.SByte);
                case TypeCode.Single: sql_md = new SqlMetaData(name, SqlDbType.Real); break;
                case TypeCode.String: sql_md = new SqlMetaData(name, SqlDbType.NVarChar, column.MaxLength);
                    break;
                case TypeCode.UInt16: throw InvalidDataTypeCode(TypeCode.UInt16);
                case TypeCode.UInt32: throw InvalidDataTypeCode(TypeCode.UInt32);
                case TypeCode.UInt64: throw InvalidDataTypeCode(TypeCode.UInt64);
                case TypeCode.Object:
                    sql_md = SqlMetaDataFromObjectColumn(name, column, clrType);
                    if (sql_md == null)
                    {
                        // Unknown type, try to treat it as string;
                        sql_md = new SqlMetaData(name, SqlDbType.NVarChar, column.MaxLength);
                        coerceToString = true;
                    }
                    break;

                default: throw UnknownDataType(clrType);
            }

            return sql_md;
        }

        private static SqlMetaData SqlMetaDataFromObjectColumn(string name, DataColumn column, Type clrType)
        {
            SqlMetaData sql_md = null;
            if (clrType == typeof(System.Byte[]) || clrType == typeof(SqlBinary) || clrType == typeof(SqlBytes) ||
        clrType == typeof(System.Char[]) || clrType == typeof(SqlString) || clrType == typeof(SqlChars))
                sql_md = new SqlMetaData(name, SqlDbType.VarBinary, column.MaxLength);
            else if (clrType == typeof(System.Guid))
                sql_md = new SqlMetaData(name, SqlDbType.UniqueIdentifier);
            else if (clrType == typeof(System.Object))
                sql_md = new SqlMetaData(name, SqlDbType.Variant);
            else if (clrType == typeof(SqlBoolean))
                sql_md = new SqlMetaData(name, SqlDbType.Bit);
            else if (clrType == typeof(SqlByte))
                sql_md = new SqlMetaData(name, SqlDbType.TinyInt);
            else if (clrType == typeof(SqlDateTime))
                sql_md = new SqlMetaData(name, SqlDbType.DateTime);
            else if (clrType == typeof(SqlDouble))
                sql_md = new SqlMetaData(name, SqlDbType.Float);
            else if (clrType == typeof(SqlGuid))
                sql_md = new SqlMetaData(name, SqlDbType.UniqueIdentifier);
            else if (clrType == typeof(SqlInt16))
                sql_md = new SqlMetaData(name, SqlDbType.SmallInt);
            else if (clrType == typeof(SqlInt32))
                sql_md = new SqlMetaData(name, SqlDbType.Int);
            else if (clrType == typeof(SqlInt64))
                sql_md = new SqlMetaData(name, SqlDbType.BigInt);
            else if (clrType == typeof(SqlMoney))
                sql_md = new SqlMetaData(name, SqlDbType.Money);
            else if (clrType == typeof(SqlDecimal))
                sql_md = new SqlMetaData(name, SqlDbType.Decimal, SqlDecimal.MaxPrecision, 0);
            else if (clrType == typeof(SqlSingle))
                sql_md = new SqlMetaData(name, SqlDbType.Real);
            else if (clrType == typeof(SqlXml))
                sql_md = new SqlMetaData(name, SqlDbType.Xml);
            else
                sql_md = null;

            return sql_md;
        }
                  
    }
 public static class TestSendDataSet
    {
        private const string TestConnectionString = "context connection=true";
        const int prod1ID = 750; //Product ID of Road-150 Red, 44 bicycle
        const int prod2ID = 751; //Product ID of Road-150 Red, 48 bicycle

        /// <summary>
        /// Invoke a stored procedure to get some bill of material information and 
        /// fill a data set with the two result sets.  Return the data set to the client.
        /// </summary>
        public static void DoTest()
        {
            using (SqlConnection conn = new SqlConnection(TestConnectionString))
            {
                SqlCommand cmd = conn.CreateCommand();
                cmd.CommandText = "usp_GetTwoBOMTestData";
                cmd.CommandType = CommandType.StoredProcedure;

                SqlParameter prod1Param = new SqlParameter("@ProductID1", SqlDbType.Int);
                prod1Param.Value = prod1ID;
                cmd.Parameters.Add(prod1Param);

                SqlParameter prod2Param = new SqlParameter("@ProductID2", SqlDbType.Int);
                prod2Param.Value = prod2ID;
                cmd.Parameters.Add(prod2Param);

                SqlParameter asOfDateParam = new SqlParameter("@AsOfDate", SqlDbType.DateTime);
                asOfDateParam.Value = DateTime.Now;
                cmd.Parameters.Add(asOfDateParam);

                DataSet ds = new DataSet("TestData");
                SqlDataAdapter sda = new SqlDataAdapter(cmd);
                conn.Open();
                sda.Fill(ds);

// Normally, after filling the data set, rather than immediately returning it, 
// the data would be modified before invoking SendDataSet to deliver 
// the data within the data set as a result set to the client.  For simplicity 
// this sample simply returns the data.

                DataSetUtilities.SendDataSet(ds);

            }
        }

    }

Visual Basic

Imports Microsoft.VisualBasic
Imports System
Imports System.Collections
Imports System.Data
Imports System.Diagnostics
Imports System.Collections.Generic
Imports System.Text
Imports System.Data.SqlClient
Imports System.Data.SqlTypes
Imports Microsoft.SqlServer.Server
Imports System.Runtime.InteropServices

Public Class DataSetUtilities

    Public Shared Sub SendDataSet(ByVal ds As DataSet)
        If ds Is Nothing Then
            Throw New ArgumentException("SendDataSet requires a non-null data set.")
        Else
            For Each dt As DataTable In ds.Tables
                SendDataTable(dt)
            Next
        End If
    End Sub

    Public Shared Sub SendDataTable(ByVal dt As DataTable)
        Dim coerceToString() As Boolean = Nothing ' Do we need to coerce this column to string?
        Dim metaData As SqlMetaData() = ExtractDataTableColumnMetaData(dt, coerceToString)

        Dim record As New SqlDataRecord(metaData)
        Dim pipe As SqlPipe = SqlContext.Pipe
        pipe.SendResultsStart(record)

        Try
            For Each row As DataRow In dt.Rows
                For index As Integer = 0 To record.FieldCount - 1
                    Dim value As Object = row(index)
                    If Nothing Is value AndAlso coerceToString(index) Then
                        value = value.ToString()
                    End If

                    record.SetValue(index, value)
                Next

                pipe.SendResultsRow(record)
            Next
        Finally
            pipe.SendResultsEnd()
        End Try
    End Sub

    Private Shared Function ExtractDataTableColumnMetaData(ByVal dt As DataTable, <Out()> ByRef coerceToString() As Boolean) As SqlMetaData()
        Dim metaDataResult(dt.Columns.Count - 1) As SqlMetaData
        coerceToString = New Boolean(dt.Columns.Count - 1) {}
        For index As Integer = 0 To dt.Columns.Count - 1
            Dim column As DataColumn = dt.Columns(index)
            metaDataResult(index) = SqlMetaDataFromColumn(column, coerceToString(index))
        Next

        Return metaDataResult
    End Function
    Private Shared Function InvalidDataTypeCode(ByVal code As TypeCode) As Exception
        Return New ArgumentException("Invalid type: " & code.ToString())
    End Function

    Private Shared Function UnknownDataType(ByVal clrType As Type) As Exception
        Return New ArgumentException("Unknown type: " & clrType.ToString())
    End Function

    Private Shared Function SqlMetaDataFromColumn(ByVal column As DataColumn, ByRef coerceToString As Boolean) As SqlMetaData
        coerceToString = False
        Dim sql_md As SqlMetaData = Nothing
        Dim clrType As Type = column.DataType
        Dim name As String = column.ColumnName
        Select Case Type.GetTypeCode(clrType)
            Case TypeCode.Boolean
                sql_md = New SqlMetaData(name, SqlDbType.Bit)
            Case TypeCode.Byte
                sql_md = New SqlMetaData(name, SqlDbType.TinyInt)
            Case TypeCode.Char
                sql_md = New SqlMetaData(name, SqlDbType.NVarChar, 1)
            Case TypeCode.DateTime
                sql_md = New SqlMetaData(name, SqlDbType.DateTime)
            Case TypeCode.DBNull
                Throw InvalidDataTypeCode(TypeCode.DBNull)
            Case TypeCode.Decimal
                sql_md = New SqlMetaData(name, SqlDbType.Decimal)
            Case TypeCode.Double
                sql_md = New SqlMetaData(name, SqlDbType.Float)
            Case TypeCode.Empty
                Throw InvalidDataTypeCode(TypeCode.Empty)
            Case TypeCode.Int16
                sql_md = New SqlMetaData(name, SqlDbType.SmallInt)
            Case TypeCode.Int32
                sql_md = New SqlMetaData(name, SqlDbType.Int)
            Case TypeCode.Int64
                sql_md = New SqlMetaData(name, SqlDbType.BigInt)
            Case TypeCode.SByte
                Throw InvalidDataTypeCode(TypeCode.SByte)
            Case TypeCode.Single
                sql_md = New SqlMetaData(name, SqlDbType.Real)
            Case TypeCode.String
                sql_md = New SqlMetaData(name, SqlDbType.NVarChar, column.MaxLength)
            Case TypeCode.UInt16
                Throw InvalidDataTypeCode(TypeCode.UInt16)
            Case TypeCode.UInt32
                Throw InvalidDataTypeCode(TypeCode.UInt32)
            Case TypeCode.UInt64
                Throw InvalidDataTypeCode(TypeCode.UInt64)
            Case TypeCode.Object
                sql_md = SqlMetaDataFromObjectColumn(name, column, clrType)
                If sql_md Is Nothing Then
                    ' Unknown type, try to treat it as string
                    sql_md = New SqlMetaData(name, SqlDbType.NVarChar, column.MaxLength)
                    coerceToString = True
                End If
            Case Else
                Throw UnknownDataType(clrType)
        End Select

        Return sql_md
    End Function

    Private Shared Function SqlMetaDataFromObjectColumn(ByVal name As String, ByVal column As DataColumn, ByVal clrType As Type) As SqlMetaData
        Dim sql_md As SqlMetaData = Nothing

        If (clrType Is GetType(System.Byte()) OrElse clrType Is GetType(SqlBinary) OrElse clrType Is GetType(SqlBytes) _
            OrElse clrType Is GetType(System.Char()) OrElse clrType Is GetType(SqlString) OrElse clrType Is GetType(SqlChars)) Then
            sql_md = New SqlMetaData(name, SqlDbType.VarBinary, column.MaxLength)
        ElseIf (clrType Is GetType(System.Guid)) Then
            sql_md = New SqlMetaData(name, SqlDbType.UniqueIdentifier)
        ElseIf (clrType Is GetType(System.Object)) Then
            sql_md = New SqlMetaData(name, SqlDbType.Variant)
        ElseIf (clrType Is GetType(SqlBoolean)) Then
            sql_md = New SqlMetaData(name, SqlDbType.Bit)
        ElseIf (clrType Is GetType(SqlByte)) Then
            sql_md = New SqlMetaData(name, SqlDbType.TinyInt)
        ElseIf (clrType Is GetType(SqlDateTime)) Then
            sql_md = New SqlMetaData(name, SqlDbType.DateTime)
        ElseIf (clrType Is GetType(SqlDouble)) Then
            sql_md = New SqlMetaData(name, SqlDbType.Float)
        ElseIf (clrType Is GetType(SqlGuid)) Then
            sql_md = New SqlMetaData(name, SqlDbType.UniqueIdentifier)
        ElseIf (clrType Is GetType(SqlInt16)) Then
            sql_md = New SqlMetaData(name, SqlDbType.SmallInt)
        ElseIf (clrType Is GetType(SqlInt32)) Then
            sql_md = New SqlMetaData(name, SqlDbType.Int)
        ElseIf (clrType Is GetType(SqlInt64)) Then
            sql_md = New SqlMetaData(name, SqlDbType.BigInt)
        ElseIf (clrType Is GetType(SqlMoney)) Then
            sql_md = New SqlMetaData(name, SqlDbType.Money)
        ElseIf (clrType Is GetType(SqlDecimal)) Then
            sql_md = New SqlMetaData(name, SqlDbType.Decimal, SqlDecimal.MaxPrecision, 0)
        ElseIf (clrType Is GetType(SqlSingle)) Then
            sql_md = New SqlMetaData(name, SqlDbType.Real)
        ElseIf (clrType Is GetType(SqlXml)) Then
            sql_md = New SqlMetaData(name, SqlDbType.Xml)
        Else
            sql_md = Nothing
        End If

        Return sql_md
    End Function
End Class

Public Class TestSendDataSet
    Private Const TestConnectionString As String = "context connection=true"
    Private Const prod1ID As Integer = 750  'Product ID of Road-150 Red, 44 bicycle
    Private Const prod2ID As Integer = 751  'Product ID of Road-150 Red, 48 bicycle

    ''' <summary>
    ''' Invoke a stored procedure to get some bill of material information and 
    ''' fill a data set with the two result sets.  Return the data set to the client.

    <SqlProcedure(Name:="usp_TestSendDataSet")> _
    Public Shared Sub DoTest()
        Dim conn As New SqlConnection(TestConnectionString)
        Try
            Dim cmd As SqlCommand = conn.CreateCommand()
            cmd.CommandText = "usp_GetTwoBOMTestData"
            cmd.CommandType = CommandType.StoredProcedure

            Dim prod1Param As New SqlParameter("@ProductID1", SqlDbType.Int)
            prod1Param.Value = prod1ID
            cmd.Parameters.Add(prod1Param)

            Dim prod2Param As New SqlParameter("@ProductID2", SqlDbType.Int)
            prod2Param.Value = prod2ID
            cmd.Parameters.Add(prod2Param)

            Dim asOfDateParam As New SqlParameter("@AsOfDate", SqlDbType.DateTime)
            asOfDateParam.Value = DateTime.Now
            cmd.Parameters.Add(asOfDateParam)

            Dim ds As New DataSet("TestData")
            Dim sda As New SqlDataAdapter(cmd)
            conn.Open()
            sda.Fill(ds)

            ' Normally, after filling the data set, rather than immediately returning it, 
            ' the data would be modified before invoking SendDataSet to deliver 
            ' the data within the data set as a result set to the client.  For simplicity 
            ' this sample simply returns the data.
            DataSetUtilities.SendDataSet(ds)
        Finally
            conn.Dispose()
        End Try
    End Sub
End Class

This is the Transact-SQL installation script (Install.sql), which deploys the assembly and creates the stored procedures.

USE AdventureWorks;
GO

IF EXISTS (SELECT * FROM sys.procedures WHERE name = N'usp_GetTwoBOMTestData')
DROP PROCEDURE usp_GetTwoBOMTestData;
GO

IF EXISTS (SELECT * FROM sys.procedures WHERE name = N'usp_TestSendDataSet')
DROP PROCEDURE usp_TestSendDataSet;
GO

IF EXISTS (SELECT * FROM sys.assemblies WHERE name = N'SendDataSet') 
DROP ASSEMBLY SendDataSet;
GO

-- Procedure used to generate test data to fill the data set being returned to the client
CREATE PROCEDURE usp_GetTwoBOMTestData
(
@ProductID1 int,
@ProductID2 int,
@AsOfDate DateTime
)
AS
BEGIN
EXEC uspGetBillOfMaterials @ProductID1, @AsOfDate;
EXEC uspGetBillOfMaterials @ProductID2, @AsOfDate;
END;
GO


DECLARE @SamplesPath nvarchar(1024)
-- You may need to modify the value of the this variable if you have installed the sample someplace other than the default location.
Set @SamplesPath = N'C:\MySample\'

CREATE ASSEMBLY SendDataSet from @SamplesPath +'SendDataSet.dll'
WITH PERMISSION_SET = Safe;
GO

CREATE PROCEDURE usp_TestSendDataSet
AS
EXTERNAL NAME [SendDataSet].[TestSendDataSet].[DoTest];
GO

This is the Transact-SQL test script (test.sql), which tests the sample.

USE AdventureWorks
GO

EXEC usp_TestSendDataSet
GO

The following Transact-SQL removes the assembly and stored procedure from the database.

USE AdventureWorks
GO

IF EXISTS (SELECT * FROM sys.procedures WHERE name = N'usp_GetTwoBOMTestData')
DROP PROCEDURE usp_GetTwoBOMTestData;
GO

IF EXISTS (SELECT * FROM sys.procedures WHERE name = N'usp_TestSendDataSet')
DROP PROCEDURE usp_TestSendDataSet;
GO

IF EXISTS (SELECT * FROM sys.assemblies WHERE name = N'SendDataSet') 
DROP ASSEMBLY SendDataSet;
GO

See Also

Usage Scenarios and Examples for Common Language Runtime (CLR) Integration