🧮What is SSDT?

SQL Server Data Tools: The real purpose of SSDT

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What is SSDT? SQL Server Data Tools: The real purpose of SSDT. Where SSDT fits in your architecture

It is not SQL Server itself.

It is not SQL Server Management Studio (SSMS).

It is a development framework inside Visual Studio for treating a database like source code.

Think of it this way:

C# Project (.csproj)
        │
        ▼
Compiles into an EXE/DLL

────────────────────────────

SQL Database Project (.sqlproj)
        │
        ▼
Compiles into a Database Model (.dacpac)

The real purpose of SSDT

Without SSDT, developers often work like this:

SSMS
   │
   ├── Create Table
   ├── Modify Procedure
   ├── Create View
   ├── Backup SQL Script

Problems:

• No version control
  

• Hard to compare changes
  

• Difficult team collaboration
  

• Manual deployments
  

• Easy to overwrite someone else’s work
  

---

With SSDT:

Visual Studio
       │
       ▼
Database Project
       │
       ▼
Source Control (Git)
       │
       ▼
Build
       │
       ▼
Publish
       │
       ▼
SQL Server

Everything becomes repeatable and version-controlled.

---

What SSDT actually builds

Many people think SSDT builds a database.

Not exactly.

It builds a database model.

SQL Files
│
├── Table.sql
├── View.sql
├── Procedure.sql
├── Function.sql
└── Type.sql

↓

SQL Database Project

↓

DACPAC
(Database Model)

A DACPAC (Data-tier Application Package) is a compiled representation of your database schema.

It contains:

• Tables
  

• Views
  

• Functions
  

• Procedures
  

• Keys
  

• Constraints
  

• Types
  

• Sequences
  

It does not contain your application data.

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Publish Process

When you click Publish, SSDT does something very clever.

Suppose your project contains:

Vehicle

with 8 columns.

The production database contains:

Vehicle

with only 7 columns.

SSDT compares them:

Project

Vehicle
    DoorNumber
    PlateNumber
    Capacity

↓

Database

Vehicle
    DoorNumber
    PlateNumber

It automatically generates:

ALTER TABLE dbo.Vehicle
ADD Capacity DECIMAL(18,2);

You don’t write migration scripts yourself.

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Hi, I’m Wajid Khan. I am trying to explain computer stuff in a simple and engaging manner, so that even non-techies can easily understand, and delivered to your inbox biweekly.

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