1# SQL Database - SDK Patterns
2 
3## Node.js (mssql)
4 
5```javascript
6const sql = require('mssql');
7 
8const config = {
9  server: process.env.SQL_SERVER,
10  database: process.env.SQL_DATABASE,
11  authentication: {
12    type: 'azure-active-directory-default'
13  },
14  options: {
15    encrypt: true
16  }
17};
18 
19const pool = await sql.connect(config);
20```
21 
22## Python (pyodbc)
23 
24> **Auth:** `DefaultAzureCredential` is for local development. See [auth-best-practices.md](../../auth-best-practices.md) for production patterns.
25 
26```python
27import pyodbc
28from azure.identity import DefaultAzureCredential
29 
30credential = DefaultAzureCredential()
31token = credential.get_token("https://database.windows.net/.default")
32 
33conn = pyodbc.connect(
34    f"Driver={{ODBC Driver 18 for SQL Server}};"
35    f"Server={os.environ['SQL_SERVER']};"
36    f"Database={os.environ['SQL_DATABASE']};"
37    f"Authentication=ActiveDirectoryMsi"
38)
39```
40 
41## .NET (Entity Framework Core)
42 
43**Required NuGet Packages:**
44```bash
45dotnet add package Microsoft.EntityFrameworkCore.SqlServer
46dotnet add package Microsoft.Data.SqlClient --version 5.1.0
47dotnet add package Azure.Identity
48```
49 
50**Connection string (Entra ID):**
51```
52Server=tcp:{server}.database.windows.net,1433;Database={database};Authentication=Active Directory Default;Encrypt=True;
53```
54 
55**Configuration:**
56```csharp
57services.AddDbContext<AppDbContext>(options =>
58    options.UseSqlServer(
59        Configuration.GetConnectionString("DefaultConnection"),
60        sqlOptions => sqlOptions.EnableRetryOnFailure()
61    ));
62```
63 
64**appsettings.json:**
65```json
66{
67  "ConnectionStrings": {
68    "DefaultConnection": "Server=tcp:myserver.database.windows.net,1433;Database=mydb;Authentication=Active Directory Default;Encrypt=True;"
69  }
70}
71```
72 
73## Connection String Format
74 
75```
76Server=tcp:{server}.database.windows.net,1433;Database={database};Authentication=Active Directory Default;Encrypt=True;
77```
78