---
source_files:
  - DataPRO/UnitTest/DatabaseUnitTesting/Utilities/ObjectsToCompare.cs
  - DataPRO/UnitTest/DatabaseUnitTesting/Utilities/DatabaseAdapter.cs
  - DataPRO/UnitTest/DatabaseUnitTesting/Utilities/DatabaseComparer.cs
generated_at: "2026-04-17T15:54:33.868933+00:00"
model: "zai-org/GLM-5-FP8"
schema_version: 1
sha256: "f31068a46fa2e835"
---

# Database Unit Testing Utilities Documentation

## 1. Purpose

This module provides internal utilities for comparing database objects between two databases, primarily designed to support database unit testing scenarios. It enables snapshot creation/management, object-level data comparison, and difference reporting. The three classes work together: `ObjectsToCompare` serves as a configuration container for comparison pairs, `DatabaseAdapter` provides low-level database operations (including snapshot management), and `DatabaseComparer` orchestrates the actual data comparison logic using set-based SQL operations.

---

## 2. Public Interface

### ObjectsToCompare (internal class)

A configuration container that holds metadata about two database objects to be compared.

**Constructor:**
```csharp
public ObjectsToCompare(string schema1Name, string object1Name, string schema2Name, string object2Name)
```
Initializes a new comparison pair with schema and object names for both sides.

**Properties:**
| Property | Type | Description |
|----------|------|-------------|
| `Schema1Name` | `string` | Schema name of the first object |
| `Object1Name` | `string` | Name of the first object |
| `Schema2Name` | `string` | Schema name of the second object |
| `Object2Name` | `string` | Name of the second object |
| `Qualified1` | `string` | Returns `_schema1Name + "." + _object1Name` |
| `Qualified2` | `string` | Returns `_schema2Name + "." + _object2Name` |
| `ColumnsToIgnore` | `IEnumerable<string>` | Returns the list of columns to exclude from comparison |

**Methods:**
```csharp
public void AddColumnToIgnore(string columnName)
```
Adds a column name to the internal `_columnsToIgnore` list.

---

### DatabaseAdapter (internal class)

Provides low-level database operations including snapshot management.

**Constructor:**
```csharp
internal DatabaseAdapter(SqlConnection connection)
```
Stores the connection and opens it if currently closed.

**Methods:**
```csharp
internal bool IsSnapshot(string name)
```
Queries `sys.databases` to check if the named database is a snapshot (checks if `source_database_id` is not null/DBNull).

```csharp
internal void UseDatabase(string databaseName)
```
Executes `USE [databaseName]` to switch the connection context.

```csharp
internal void CreateSnapshot(string databaseName, string snapshotName)
```
Creates a database snapshot with the file stored at `C:\Temp\[snapshotName]`.

```csharp
internal void DropSnapshot(string snapshotName)
```
Drops the specified snapshot. Throws `ArgumentException` if the named database is not a snapshot.

---

### DatabaseComparer (internal class)

Orchestrates comparison