Array Parameter Sample

 

Applies To: SQL Server 2016 Preview

Sometimes it is useful to create, update, or delete a set of rows in a database. There are several approaches you could use to achieve that goal. One of them is to pass an array of information from a client to a common language runtime (CLR) integration stored procedure on the server by using a CLR integration user-defined data type. The nature of such user-defined data types limits the size of the data provided to the server to 8000 bytes. Therefore, this approach is not satisfactory for large or complex data. If the data that is being manipulated is small and simple, this approach can be much more efficient than calling a stored procedure for each row. By passing an array, the order of data is preserved for those applications where the order is significant.This sample contains the following:

  1. The ContactTypeNames user-defined data type. This contains a list of desired contact type names.

  2. The usp_EnsureContactTypeNames stored procedure implemented as a Microsoft Visual C# or Microsoft Visual Basic method. This accepts an instance of the ContactTypeNames user-defined data type and inserts new rows in the Person.ContactType table for any contact names that are contained in the user-defined data type instance which are not already present in the table.

  3. The TestArrayParameter console application. This creates an instance of the ContactTypeNames user-defined data type based on the command line parameters passed in, and then invokes the usp_EnsureContactTypeNames stored procedure by passing the user-defined data type instance as a parameter.

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 ContactTypeNames.vb (for the Visual Basic sample) or ContactTypeNames.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 ContactTypeNames.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 ContactTypeNames.cs

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

  6. Locate the appropriate line in the file Program (around line 24) and replace XXX with the name of your instance of SQL Server

    • Dim connection As New SqlConnection("data source=XXX;initial catalog=AdventureWorks;Integrated Security=SSPI")

    • using (SqlConnection connection = new SqlConnection("data source=XXX;initial catalog=AdventureWorks;Integrated Security=SSPI"))

  7. Compile the sample code into the required executable 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.Deployment.dll,C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.dll,C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.Drawing.dll,C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.Windows.Forms.dll,C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.Xml.dll,C:\MySample\ContactTypeNames.dll /out:TestArrayParameter Program.vb

    • Csc /reference:ContactTypeNames.dll /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 /out:TestArrayParameter.exe Program.cs

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

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

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

    • sqlcmd -E -I -i install.sql
  11. Test the application by executing the following line at the command prompt:

    • TestArrayParameter "Executive Sales Representative" "Executive Sales Manager"
  12. Copy the Transact-SQL cleanup script into a file and save it as cleanup.sql in the sample directory.

  13. Execute the script with the following command

    • sqlcmd -E -I -i cleanup.sql

Sample Code

The following are the code listings for this sample.

This is the code for the Library ContactTypeNames.

C#

#region Using directives

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

#endregion

    // This class is used to demonstrate passing an array of a fairly small number of reasonably small strings
    // to a CLR integration based stored procedure on the server.  Because a UDT is limited to 8000 bytes
    // this approach will not work well for large numbers of strings or long strings.  See the contact
    // creation stored procedure in the AdventureWorks CLR integration sample for an alternative approach
    // using XML which does not have these limitations.
    [Serializable]
    [Microsoft.SqlServer.Server.SqlUserDefinedType(Microsoft.SqlServer.Server.Format.UserDefined, IsByteOrdered = true, MaxByteSize = 8000)]
    public class ContactTypeNames : INullable, Microsoft.SqlServer.Server.IBinarySerialize
    {

        #region Constructors
        private const int maxByteSize = 8000;

        public ContactTypeNames()
        {
        }

        public ContactTypeNames(string[] names)
        {
            int numberOfCharacters = 0;
            foreach (string name in names)
            {
                if (name.Length == 0) 
                    throw new ArgumentException("Zero length names are not allowed");
                numberOfCharacters += name.Length;
            }
            int dataByteSize = numberOfCharacters*2 //UTF-16 characters take 2 bytes
                + names.Length*4  //Four byte header for each string
                + 4                 //Four byte header for null string at end
                + 1;                //One byte boolean for null flag
            if (dataByteSize >= maxByteSize)
                throw new ArgumentException(string.Format(CultureInfo.InvariantCulture, "Data provided occupies {0} bytes but only {1} bytes "
                    + "are available", dataByteSize, maxByteSize));

            this._names = names;
        }
        #endregion

        #region Accessors
        public string[] GetTypeNameArray()
        {
            //Don't let caller modify our copy of the array
            return (string[])_names.Clone();
        }

        //This has an odd API because we can only define Transact-SQL functions on static methods.
        [SqlFunctionAttribute(FillRowMethodName = "FillNameRow")]
        public static IEnumerable GetContactTypeNames(ContactTypeNames names)
        {
            if (names == null)
                throw new ArgumentNullException("names");

            return names.GetTypeNameArray();
        }

        public static void FillNameRow(object nameArrayElement, out string contactName)
        {
            contactName = (string)nameArrayElement;
        }

        #endregion

        #region String Conversions

        /// <summary>
        /// The string format for contact type names is a sequence of names separated by commas
        /// </summary>
        /// <param name="s">a string containing contact type names separated by commas</param>
        /// <returns>An instance of contact type name containing the specified names</returns>
        [Microsoft.SqlServer.Server.SqlMethod(DataAccess = Microsoft.SqlServer.Server.DataAccessKind.None, IsDeterministic = false, IsMutator = false, IsPrecise = false,
        SystemDataAccess = Microsoft.SqlServer.Server.SystemDataAccessKind.None)]
        public static ContactTypeNames Parse(SqlString s)
        {
            if (s.IsNull)
                return Null;
            return new ContactTypeNames(s.Value.Split(new char[] {','}));
        }

        /// <summary>
        /// Convert the contact type names to a string
        /// </summary>
        /// <returns>The contact type names separated by commas</returns>
        public override string ToString()
        {
            if (this.IsNull)
                return null;

            StringBuilder sb = new StringBuilder();
            foreach (string name in _names)
            {
                if (sb.Length > 0) sb.Append(", ");
                sb.Append(name);
            }

            return sb.ToString();
        }
        #endregion

        #region INullable Members

        public static ContactTypeNames Null
        {
            get
            {
                return new ContactTypeNames();
            }
        }
        public bool IsNull
        {
            get 
            { 
                return _names == null; 
            }
        }

        #endregion

        #region IBinarySerialize Members

        //Format: 
        //Byte 1: Null flag (boolean) (true = null)
        //Byte 2 - 7994: Strings with 4 byte length headers,
        //               last string is a zero length string.
        //This format is in part dictated by how the BinaryWriter serializes strings.  See
        //the Microsoft .NET Framework documentation on System.IO.BinaryWriter for more details.

        public void Read(System.IO.BinaryReader r)
        {
            if (r.ReadBoolean())
            {
                _names = null;
                return;
            }
            List<String> nameList = new List<String>();
            string name;
            while ((name = r.ReadString()).Length != 0)
            {
                nameList.Add(name);
            }
            _names = new string[nameList.Count];
            nameList.CopyTo(_names);
        }

        public void Write(System.IO.BinaryWriter w)
        {
            if (w == null)
                throw new ArgumentNullException("w");

            w.Write(this.IsNull);
            foreach (string name in _names)
            {
                w.Write(name);
            }
            w.Write(string.Empty);            
        }

        #endregion

        #region Private Implementation

        private string[] _names;
        #endregion
    }

Visual Basic

#Region "Using directives"
Imports System
Imports System.Data
Imports System.Data.Sql
Imports System.Data.SqlTypes
Imports System.Collections
Imports System.Collections.Generic
Imports System.Text
Imports System.Globalization
Imports Microsoft.SqlServer.Server
Imports System.Runtime.InteropServices
#End Region

' This class is used to demonstrate passing an array of a fairly small number of reasonably small strings
' to a CLR integration based stored procedure on the server.  Because a UDT is limited to 8000 bytes
' this approach will not work well for large numbers of strings or long strings.  See the contact
' creation stored procedure in the AdventureWorks CLR integration sample for an alternative approach
' using XML which does not have these limitations.
<Serializable()> _
<SqlUserDefinedType(Format.UserDefined, IsByteOrdered:=True, maxByteSize:=8000), CLSCompliant(False)> _
Public Class ContactTypeNames
    Implements INullable, IBinarySerialize

#Region "Constructors"
    Private Const maxByteSize As Integer = 8000

    Public Sub New()
    End Sub

    Public Sub New(ByVal names() As String)
        Dim numberOfCharacters As Integer = 0

        For Each name As String In names
            If name.Length = 0 Then
                Throw New ArgumentException("Zero length names are not allowed")
            End If

            numberOfCharacters += name.Length
        Next

        'UTF-16 characters take 2 bytes
        'Four byte header for each string
        'Four byte header for null string at end
        'One byte boolean for null flag
        Dim dataByteSize As Integer = numberOfCharacters * 2 _
            + names.Length * 4 _
            + 4 _
            + 1

        If dataByteSize >= maxByteSize Then
            Throw New ArgumentException(String.Format(CultureInfo.InvariantCulture, _
                "Data provided occupies {0} bytes but only {1} bytes are available", _
                dataByteSize, maxByteSize))
        End If

        Me._names = names
    End Sub
#End Region

#Region "Accessors"

    Public Function GetTypeNameArray() As String()
        'Don't let caller modify our copy of the array
        Return CType(Me._names.Clone(), String())
    End Function

    'This has an odd API because we can only define Transact-SQL functions on static methods.
    <SqlFunction(FillRowMethodName:="FillNameRow", TableDefinition:="[Name] [Name]")> _
    Public Shared Function GetContactTypeNames(ByVal names As ContactTypeNames) As IEnumerable
        If names Is Nothing Then
            Throw New ArgumentNullException("names")
        End If

        Return names.GetTypeNameArray()
    End Function

    Public Shared Sub FillNameRow(ByVal nameArrayElement As Object, <Out()> ByRef contactName As String)
        contactName = CStr(nameArrayElement)
    End Sub

#End Region

#Region "String Conversions"

    ''' <summary>
    ''' The string format for contact type names is a sequence of names separated by commas
    ''' </summary>
    ''' <param name="s">a string containing contact type names separated by commas</param>
    ''' <returns>An instance of contact type name containing the specified names</returns>
    <Microsoft.SqlServer.Server.SqlMethod(DataAccess:=Microsoft.SqlServer.Server.DataAccessKind.None, IsDeterministic:=False, IsMutator:=False, IsPrecise:=False, SystemDataAccess:=Microsoft.SqlServer.Server.SystemDataAccessKind.None)> _
    Public Shared Function Parse(ByVal s As SqlString) As ContactTypeNames
        If s.IsNull Then
            Return Nothing
        End If

        Return New ContactTypeNames(s.Value.Split(New Char() {","c}))
    End Function

    ''' <summary>
    ''' Convert the contact type names to a string
    ''' </summary>
    ''' <returns>The contact type names separated by commas</returns>
    Public Overrides Function ToString() As String
        If Me.IsNull Then
            Return Nothing
        End If

        Dim sb As New StringBuilder()

        For Each name As String In Me._names
            If sb.Length > 0 Then
                sb.Append(", ")
            End If

            sb.Append(name)
        Next name

        Return sb.ToString()
    End Function
#End Region

#Region "INullable Members"

    Shared ReadOnly Property Null() As ContactTypeNames
        Get
            Return New ContactTypeNames()
        End Get
    End Property

    Public ReadOnly Property IsNull() As Boolean Implements INullable.IsNull
        Get
            Return Me._names Is Nothing
        End Get
    End Property

#End Region

#Region "IBinarySerialize Members"

    'Format: 
    'Byte 1: Null flag (boolean) (true = null)
    'Byte 2 - 7994: Strings with 4 byte length headers,
    '               last string is a zero length string.
    'This format is in part dictated by how the BinaryWriter serializes strings.  See
    'the Microsoft .NET Framework documentation on System.IO.BinaryWriter for more details.
    Public Sub Read(ByVal r As System.IO.BinaryReader) Implements IBinarySerialize.Read
        If r.ReadBoolean() Then
            Me._names = Nothing
            Return
        End If

        Dim nameList As New List(Of String)
        Dim name As String = r.ReadString()
        While name.Length <> 0
            nameList.Add(name)
            name = r.ReadString()
        End While

        Me._names = New String(nameList.Count - 1) {}
        nameList.CopyTo(Me._names)
    End Sub

    Public Sub Write(ByVal w As System.IO.BinaryWriter) Implements IBinarySerialize.Write
        If w Is Nothing Then
            Throw New ArgumentNullException("w")
        End If

        w.Write(Me.IsNull)

        For Each name As String In Me._names
            w.Write(name)
        Next

        w.Write(String.Empty)
    End Sub

#End Region

#Region "Private Implementation"
    Private _names() As String
#End Region

End Class

This is the code for the test executable.

C#

#region Using directives

using System;
using System.Collections.Generic;
using System.Text;
using System.IO;
using System.Data;
using System.Data.Sql;
using System.Data.SqlTypes;
using System.Data.SqlClient;
#endregion

    class Program
    {
        static void Main(string[] args)
        {
            if (args.Length == 0)
            {
                Console.WriteLine("Usage: TestArrayParameter contactTypeName1 "
                    + "contactTypeName2 ... contactTypeNamen");
                return;
            }
            using (SqlConnection connection = new SqlConnection("data source=XXX;initial catalog=AdventureWorks;Integrated Security=SSPI"))
            {
                connection.Open();
                ShowTypeNames(connection, "before any inserts");

                SqlCommand command = connection.CreateCommand();
                command.CommandText = "usp_EnsureContactTypeNames";
                command.CommandType = CommandType.StoredProcedure;
                SqlParameter namesParameter = new SqlParameter("@names", SqlDbType.Udt);
                namesParameter.UdtTypeName = "ContactTypeNames";
                namesParameter.Value = new ContactTypeNames(args);
                command.Parameters.Add(namesParameter);
                command.ExecuteNonQuery();

                ShowTypeNames(connection, "after any inserts");

            }

        }

        private static void ShowTypeNames(SqlConnection connection, string whenRan)
        {
            SqlCommand command = connection.CreateCommand();
            command.CommandText = "SELECT Name FROM Person.ContactType ORDER BY Name";
            using (SqlDataReader reader = command.ExecuteReader())
            {
                Console.BackgroundColor = ConsoleColor.Blue;
                Console.Write("Contact type names {0}: ", whenRan);
                Console.ResetColor();
                bool first = true;
                while (reader.Read())
                {
                    if (!first) Console.Write(", ");
                    Console.Write(reader[0].ToString());
                    first = false;
                }
                Console.WriteLine("");
                Console.WriteLine("");
            }

        }
    }

Visual Basic

#Region "Using directives"
Imports System
Imports System.Collections.Generic
Imports System.Text
Imports System.IO
Imports System.Data
Imports System.Data.Sql
Imports System.Data.SqlTypes
Imports System.Data.SqlClient
#End Region

Class Program

    Shared Sub Main(ByVal args() As String)
        If args.Length = 0 Then
            Console.WriteLine("Usage: TestArrayParameter contactTypeName1 " _
                + "contactTypeName2 ... contactTypeNamen")
            Return
        End If

        Dim connection As New SqlConnection("data source=XXX;initial catalog=AdventureWorks;Integrated Security=SSPI")
        Try
            connection.Open()
            ShowTypeNames(connection, "Before any inserts")

            Dim command As SqlCommand = connection.CreateCommand()
            command.CommandText = "usp_EnsureContactTypeNames"
            command.CommandType = CommandType.StoredProcedure
            Dim namesParameter As New SqlParameter("@names", SqlDbType.Udt)
            namesParameter.UdtTypeName = "ContactTypeNames"
            namesParameter.Value = New ContactTypeNames(args)
            command.Parameters.Add(namesParameter)
            command.ExecuteNonQuery()

            ShowTypeNames(connection, "After any inserts")
        Finally
            connection.Dispose()
        End Try
    End Sub

    Private Shared Sub ShowTypeNames(ByVal connection As SqlConnection, ByVal whenRan As String)
        Dim command As SqlCommand = connection.CreateCommand()
        command.CommandText = "SELECT [Name] FROM [Person].[ContactType] ORDER BY Name"
        Dim reader As SqlDataReader = command.ExecuteReader()
        Try
            Console.BackgroundColor = ConsoleColor.Blue
            Console.Write("Contact type names {0}: ", whenRan)
            Console.ResetColor()
            Dim first As Boolean = True
            While reader.Read()
                If Not first Then
                    Console.Write(", ")
                End If

                Console.Write(reader(0).ToString())
                first = False
            End While

            Console.WriteLine("")
            Console.WriteLine("")
        Finally
            reader.Dispose()
        End Try

    End Sub
End Class

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

USE AdventureWorks
GO

-- Drop existing sprocs, type, and assemblies if any.

IF EXISTS (SELECT * FROM sys.procedures WHERE [name] = 'usp_EnsureContactTypeNames')
DROP PROCEDURE usp_EnsureContactTypeNames;
GO


IF EXISTS (SELECT * FROM sys.objects WHERE [name] = N'GetContactTypeNames' and (type = 'FS' or type = 'FT'))  
DROP FUNCTION [GetContactTypeNames];
GO


IF EXISTS (SELECT * FROM sys.types WHERE [name] = 'ContactTypeNames')
DROP TYPE ContactTypeNames;
GO

IF EXISTS (SELECT * FROM sys.assemblies WHERE [name] = 'ContactTypeNames')
DROP ASSEMBLY ContactTypeNames;
GO

-- Add assemblies, type, and sproc

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= 'C:\MySample\'
CREATE ASSEMBLY ContactTypeNames 
FROM @SamplesPath + 'ContactTypeNames.dll'
WITH permission_set = Safe;

CREATE TYPE ContactTypeNames
EXTERNAL NAME ContactTypeNames.ContactTypeNames;
GO


CREATE FUNCTION GetContactTypeNames
(
@names dbo.ContactTypeNames
)
RETURNS TABLE
(
[Name] [Name]
)
AS EXTERNAL NAME [ContactTypeNames].[ContactTypeNames].[GetContactTypeNames];
GO


CREATE PROCEDURE usp_EnsureContactTypeNames
(
@names dbo.ContactTypeNames
)
AS
SET NOCOUNT ON;

INSERT Person.ContactType ([Name])
SELECT [Name] FROM GetContactTypeNames(@names) AS PotentialNames
WHERE [Name] NOT IN (SELECT [Name] FROM Person.ContactType); 
GO

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

USE AdventureWorks
GO

DELETE Person.ContactType WHERE ContactTypeID > 20;
GO

-- Drop existing sprocs, type, and assemblies if any.

IF EXISTS (SELECT * FROM sys.procedures WHERE [name] = 'usp_EnsureContactTypeNames')
DROP PROCEDURE usp_EnsureContactTypeNames;
GO

IF EXISTS (SELECT * FROM sys.objects WHERE [name] = N'GetContactTypeNames' and (type = 'FS' or type = 'FT'))  
DROP FUNCTION [GetContactTypeNames];
GO

IF EXISTS (SELECT * FROM sys.types WHERE [name] = 'ContactTypeNames')
DROP TYPE ContactTypeNames;
GO

IF EXISTS (SELECT * FROM sys.assemblies WHERE [name] = 'ContactTypeNames')
DROP ASSEMBLY ContactTypeNames;
GO

See Also

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