# MSSQL Reader

Reads database schema from Microsoft SQL Server databases using a live connection.

## Features

- **Live Connection**: Connects to MSSQL databases using the Microsoft ODBC driver
- **Multi-Schema Support**: Reads multiple schemas with full support for user-defined schemas
- **Comprehensive Metadata**: Reads tables, columns, constraints, indexes, and extended properties
- **Type Mapping**: Converts MSSQL types to canonical types for cross-database compatibility
- **Extended Properties**: Extracts table and column descriptions from MS_Description
- **Identity Columns**: Maps IDENTITY columns to AutoIncrement
- **Relationships**: Derives relationships from foreign key constraints

## Connection String Format

```
sqlserver://[user[:password]@][host][:port][?query]
```

Examples:
```
sqlserver://sa:password@localhost/dbname
sqlserver://user:pass@192.168.1.100:1433/production
sqlserver://localhost/testdb?encrypt=disable
```

## Supported Constraints

- Primary Keys
- Foreign Keys (with ON DELETE and ON UPDATE actions)
- Unique Constraints
- Check Constraints

## Type Mappings

| MSSQL Type | Canonical Type |
|------------|----------------|
| INT | int |
| BIGINT | int64 |
| SMALLINT | int16 |
| TINYINT | int8 |
| BIT | bool |
| REAL | float32 |
| FLOAT | float64 |
| NUMERIC, DECIMAL | decimal |
| NVARCHAR, VARCHAR | string |
| DATETIME2 | timestamp |
| DATETIMEOFFSET | timestamptz |
| UNIQUEIDENTIFIER | uuid |
| VARBINARY | bytea |
| DATE | date |
| TIME | time |

## Usage

```go
import "git.warky.dev/wdevs/relspecgo/pkg/readers/mssql"
import "git.warky.dev/wdevs/relspecgo/pkg/readers"

reader := mssql.NewReader(&readers.ReaderOptions{
    ConnectionString: "sqlserver://sa:password@localhost/mydb",
})

db, err := reader.ReadDatabase()
if err != nil {
    panic(err)
}

// Process schema...
for _, schema := range db.Schemas {
    fmt.Printf("Schema: %s\n", schema.Name)
    for _, table := range schema.Tables {
        fmt.Printf("  Table: %s\n", table.Name)
    }
}
```

## Testing

Run tests with:
```bash
go test ./pkg/readers/mssql/...
```

For integration testing with a live MSSQL database:
```bash
docker-compose up -d mssql
go test -tags=integration ./pkg/readers/mssql/...
docker-compose down
```