SQLCLR TIPS&TRICKS

Daniel Joskovski

Owner Omnis llc, Principal Developer Daenet,

MCT Semos Educationjoskovski@t-home.mk

About me

Agenda

Why SQL CLR?

What Is Assembly and How To Get Info About?

Demo1

Create CLR Functions

Demo 2

Discussion

Encrypt/Decrypt

Why SQL CLR?

A better programming model

Improved safety and security

Ability to define data types and aggregate functions

Streamlined development through a standardized environment

Potential for improved performance and scalability

What Is Assembly

Assemblies are DLL files used in an instance of SQL Server to deploy:

Functions

Stored procedures

Triggers

User-defined aggregates

User-defined types

Getting Info About Assemblies ASSEMBLYPROPERTY('assembly_name', 'property_name')

• sys.assemblies

• sys.assembly_files

• sys.assembly_modules

Demo 1

Getting Info About Assemblies

SQL Server In-Process Specific Extensions to ADO.NET

SqlContext Object This class provides access to the other extensions by abstracting the context of a caller of a SQL Server routine that executes managed code in-process.

SqlPipe Object This class contains routines to send tabular results and messages to the client.

SqlDataRecord Object The SqlDataRecord class represents a single row of data, along with its related metadata, and allows stored procedures to return custom result sets to the client.

• SqlTriggerContext Object This class provides information on the context in which a trigger is run.

using System; using System.Data; using System.Data.Sql; using Microsoft.SqlServer.Server; using System.Data.SqlClient; using System.Data.SqlTypes; using System.Xml; using System.Text.RegularExpressions;

public class CLRTriggers{ public static void DropTableTrigger()

{ SqlTriggerContext triggContext = SqlContext.TriggerContext;switch(triggContext.TriggerAction)

{ case TriggerAction.DropTable:SqlContext.Pipe.Send("Table dropped! Here's the EventData:"); SqlContext.Pipe.Send(triggContext.EventData.Value); break; default: SqlContext.Pipe.Send("Something happened! Here's the EventData:"); SqlContext.Pipe.Send(triggContext.EventData.Value);break;}

}}

Returning Custom Result Set

Managed stored procedures can send result sets that do not come from a SqlDataReader. The SendResultsStart method, along with SendResultsRow and SendResultsEnd, allows stored procedures to send custom result sets to the client.

SendResultsStart takes a SqlDataRecord as an input. It marks the beginning of a result set and uses the record metadata to construct the metadata that describes the result set. It does not send the value of the record with SendResultsStart. All the subsequent rows, sent using SendResultsRow, must match that metadata definition.

DEMO 2

Creating Managed Objects with Visual Studio

public static void TransactionHistoryRunningSum()

{

using (SqlConnection conn = new SqlConnection("context connection=true;"))

{

SqlCommand comm = new SqlCommand();

comm.Connection = conn;

comm.CommandText = @"" +

"SELECT TransactionID, ActualCost " +

"FROM Production.TransactionHistory " +

"ORDER BY TransactionID";

SqlMetaData[] columns = new SqlMetaData[3];

columns[0] = new SqlMetaData("TransactionID", SqlDbType.Int);

columns[1] = new SqlMetaData("ActualCost", SqlDbType.Money);

columns[2] = new SqlMetaData("RunningTotal", SqlDbType.Money);

decimal RunningSum = 0;

SqlDataRecord record = new SqlDataRecord(columns);

SqlContext.Pipe.SendResultsStart(record);

conn.Open();

SqlDataReader reader = comm.ExecuteReader();

while (reader.Read())

{

decimal ActualCost = (decimal)reader[1];

RunningSum += ActualCost;

record.SetInt32(0, (int)reader[0]);

record.SetDecimal(1, ActualCost);

record.SetDecimal(2, RunningSum);

SqlContext.Pipe.SendResultsRow(record);

}

SqlContext.Pipe.SendResultsEnd();

}

}

Discusion

Other way?

Ideas?

Supported Assemblies

Microsoft.Visualbasic.dll

Mscorlib.dll

System.Data.dll

System.dll

System.Xml.dll

Microsoft.Visualc.dll

Custommarshallers.dll

System.Security.dll

System.Web.Services.dll

System.Data.SqlXml.dll.

Demo

Creating PDF document in SQLCLR using IText

Documentation used

http://msdn.microsoft.com/en-us/library/ms131102.aspx

http://msdn.microsoft.com/en-us/library/ms131075.aspx

http://msdn.microsoft.com/en-us/library/ms131070.aspx

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