La majorité des applications actuelles ont besoin d’enregistrer des informations dans une base de données locale ou serveur. Plusieurs outils existent dont Entity Framework, le plus fréquemment proposés par Microsoft, ou ADO.NET, le plus performant mais le plus complexe à exploiter. Depuis plusieurs années, nous avons construit un ensemble d’outils simples afin de nous aider dans la fabrication de la DAL de nos projets, et plus particulièrement dans la recherche de données en les transformant facilement en objets .NET. Lors de cette session, nous expliquerons l’historique de ce toolkit en le comparant à quelques outils existants sur le marché, dont ADO.NET, Entity Framework ou Dapper.NET. Ensuite, via des démos Live, je présenterai les fonctionnalités principales de SqlDatabaseCommand pour réaliser et optimiser les opérations courantes d’accès aux bases de données : récupérations de données typées, gestion des transactions, intégration de traces, gestion des exceptions, génération automatique de classe et l’injection de données pour les tests unitaires. Ces démos seront l’occasion de parler des bonnes pratiques d’accès aux bases de données de type SQL (SQL Server, SQLite, SQL Azure, etc). Finalement, je montrerai comment utiliser ce toolkit dans des procédures CLR, intégrées à SQL Server. Ces procédures accroissent de manière phénoménale les performances de gestion des données.

1. 1

2. 2
Denis Voituron
Civil engineer (Mons)
Company founder
Developer: VB3, VB.Net, C#
.Net Software Architect (NRB)
Blogger
Speaker (DevApps.be)

3. 3
• Background
• Simple Object Mapping
• SQL Server CLR Stored Procedures

4. 4

5. 5

6. 6
EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO
7839 KING PRESIDENT 17-NOV-81 5000 10
7698 BLAKE MANAGER 7839 01-MAY-81 2850 30
7756 CLARK MANAGER 7839 09-JUN-81 1500 10
... ...
... ...
7456 JONES MANAGER 7839 02-APR-81 2975 20
DEPTNO DNAME LOC
10 ACCOUNTING NEW YORK
20 RESEARCH DALLAS
30 SALES CHICAGO
40 OPERATIOS BOSTON

7. 7
using (var connection = new SqlConnection(CONNECTION_STRING))
{
connection.Open();
connection.Close();
}
SELECT ENAME FROM EMP WHERE EMPNO = 7369
using (var cmd = connection.CreateCommand())
{
cmd.CommandText = "SELECT ENAME " +
" FROM EMP " +
" WHERE EMPNO = 7369 ";
}
using (var adapter = new SqlDataAdapter(cmd))
{
DataTable table = new DataTable();
adapter.Fill(table);
string name = table.Rows[0].Field<string>("ENAME");
}

8. 8
var db = new SCOTTEntities();
var query = from e in db.EMPs
where e.EMPNO == 7369
select e.ENAME;
var name = query.First();
var db = new SCOTTEntities();
var query = from e in db.EMPs
where e.EMPNO == 7369
select e;
var name = query.First().DEPT.DNAME; SELECT TOP (1)
[Extent1].[ENAME] AS [ENAME]
FROM [dbo].[EMP] AS [Extent1]
WHERE 7369 = [Extent1].[EMPNO]
SELECT TOP (1)
[Extent1].[EMPNO] AS [EMPNO],
[Extent1].[ENAME] AS [ENAME],
[Extent1].[JOB] AS [JOB],
[Extent1].[MGR] AS [MGR],
[Extent1].[HIREDATE] AS [HIREDATE],
[Extent1].[SAL] AS [SAL],
[Extent1].[COMM] AS [COMM],
[Extent1].[DEPTNO] AS [DEPTNO]
FROM [dbo].[EMP] AS [Extent1]
WHERE 7369 = [Extent1].[EMPNO]
SELECT
[Extent1].[DEPTNO] AS [DEPTNO],
[Extent1].[DNAME] AS [DNAME],
[Extent1].[LOC] AS [LOC]
FROM [dbo].[DEPT] AS [Extent1]
WHERE [Extent1].[DEPTNO] = @V1

9. 9http://stackoverflow.com/questions/2698151/entity-framework-vs-linq-to-sql-vs-ado-net-with-stored-procedures
Performance
Speed of Development
Maintainable code (neat)
Flexibility
Scalability

10. 10http://blogs.msdn.com/b/adonet/archive/2012/02/14/sneak-preview-entity-framework-5-0-performance-improvements.aspx

11. 11

12. 12
• Library that will extend IDbConnection
• Need an opened connection
using (var connection = new SqlConnection(CONNECTION_STRING))
{
connection.Open();
string sql = "SELECT * FROM EMP WHERE EMPNO = @Id";
var emp = connection.Query<EMP>(sql, new { Id = 7369 });
}

13. 13
string sql = "SELECT * FROM EMP WHERE EMPNO = @Id";
var emp = connection.Query<EMP>(sql, new { Id = 7369 });
string sql = "SELECT * FROM EMP WHERE EMPNO = @Id";
var emp = connection.Query(sql, new { Id = 7369 });
string sql = "SELECT ENAME FROM EMP WHERE EMPNO = @Id";
var emp = connection.ExecuteScalar<string>(sql, new { Id = 7369 });
var n = connection.Execute(“DELETE FROM EMP");
var emp = connection.Query(sql, buffered: false);

14. 14
• Object and Commands
• Extension method of System.Data

15. 15
• Sample
using (var cmd = new SqlDatabaseCommand(CONNECTION_STRING))
{
}
cmd.CommandText.AppendLine(" SELECT * ");
cmd.CommandText.AppendLine(" FROM EMP ");
var emps = cmd.ExecuteTable<Employee>();
cmd.CommandText.AppendLine(" WHERE HIREDATE = @HireDate ");
cmd.Parameters.AddValues(new
{
HireDate = new DateTime(1980, 12, 17)
});

16. 16
9876 NEW
• Main methods
EMPNO ENAME
7839 KING
7698 BLAKE
7756 CLARK
...
...
7456 JONES
var emps = cmd.ExecuteTable<Employee>();
• ExecuteTable
var smith = cmd.ExecuteRow<Employee>();
• ExecuteRow
var name = cmd.ExecuteScalar<String>();
• ExecuteScalar
var n = cmd.ExecuteNonQuery();
• ExecuteQuery

17. 17
• Parameters
cmd.CommandText.AppendLine(" SELECT ENAME ")
.AppendLine(" FROM EMP ")
.AppendLine(" WHERE EMPNO = @EmpNo ")
.AppendLine(" AND HIREDATE = @HireDate ");
cmd.Parameters.AddWithValue("@EmpNo", 7369);
cmd.Parameters.AddWithValue("@HireDate", new DateTime(1980, 12, 17));
var name = cmd.ExecuteScalar();
cmd.CommandText.AppendLine(" SELECT ENAME ")
.AppendLine(" FROM EMP ")
.AppendLine(" WHERE EMPNO = @EmpNo ")
.AppendLine(" AND HIREDATE = @HireDate ");
cmd.Parameters.AddValues(new
{
EmpNo = 7369,
HireDate = new DateTime(1980, 12, 17)
});
var name = cmd.ExecuteScalar();

18. 18
• Traces
cmd.Log = Console.WriteLine;
cmd.Log = (message) =>
{
Console.WriteLine(message);
};
string formatted = cmd.GetCommandTextFormatted(QueryFormat.Text);
SELECT ENAME
FROM EMP
WHERE EMPNO = 7369
AND HIREDATE = '1970-05-04 14:15:16'
string formatted = cmd.GetCommandTextFormatted(QueryFormat.Html);
SELECT ENAME
FROM EMP
WHERE EMPNO = 7369
AND HIREDATE = '1970-05-04 14:15:16'

19. 19
• Entities Generator
// *********************************************
// Code Generated with Apps72.Dev.Data.Generator
// *********************************************
using System;
namespace Data.Tests.Entities
{
/// <summary />
public partial class BONUS
{
/// <summary />
public virtual String ENAME { get; set; }
/// <summary />
public virtual String JOB { get; set; }
/// <summary />
public virtual Int32? SAL { get; set; }
/// <summary />
public virtual Int32? COMM { get; set; }
}
/// <summary />
public partial class DEPT
{
/// <summary />
public virtual Int32 DEPTNO { get; set; }
/// <summary />
public virtual String DNAME { get; set; }
/// <summary />
public virtual String LOC { get; set; }
}
var entitiesGenerator = new SqlEntitiesGenerator(CONNECTION_STRING);
foreach (var table in entitiesGenerator.Tables)
{
...
}

20. 20
• Best Practice
public class DataService : IDataService
{
public SqlDatabaseCommand GetDatabaseCommand()
{
return new SqlDatabaseCommand(CONNECTION_STRING);
}
public SqlDatabaseCommand GetDatabaseCommand(SqlTransaction trans)
{
return new SqlDatabaseCommand(trans.Connection, trans);
}
}
using (var cmd = service.GetDatabaseCommand())
{
...
}

21. 21
• Microsoft.Data.Sqlite
• SqliteDatabaseCommand
public SqliteDatabaseCommand GetDatabaseCommand()
{
return new SqliteDatabaseCommand("Filename=Scott.db");
}
public IEnumerable<Scott.EMP> GetAllEmployees()
{
using (var cmd = this.GetDatabaseCommand())
{
cmd.CommandText.AppendLine(" SELECT * FROM EMP ");
return cmd.ExecuteTable<Scott.EMP>();
}
}

22. 22

23. 23
• What?
• Why?

24. 24
• Create a Class Library
• CLR Nuget Package

25. 25
[SqlFunction(DataAccess = DataAccessKind.Read)]
public static int GetMaximumAge()
{
using (var cmd = new SqlDatabaseCommand("context connection=true"))
{
...
}
}
CREATE FUNCTION GetMaximumAge()
RETURNS INT
AS EXTERNAL NAME SampleSqlDatabaseCommandClr.SampleCLR.GetMaximumAge

26. 26
[SqlFunction()]
public static bool IsComparableTo(string text1, string text2)
{
return text1.ComparableTo(text2) == 0;
}
SELECT dbo.IsComparableTo('Maison', 'House') -- FALSE
SELECT dbo.IsComparableTo('St Ecole', 'Saint''école&') -- TRUE
SELECT dbo.IsComparableTo('A''&é', 'aE') -- TRUE

27. 27
ADO.NET
EntityFramework
SQLite
Dapper.NET
SqlDatabaseCommand
CLR Stored Procedure
SQL Databases
Conclusion