# go-mssqldb - Microsoft's Official Go Driver for SQL Server

> Microsoft's official Go driver for SQL Server and Azure SQL Database
> For complete reference, see: llms-full.txt

## Quick Start

```go
import (
    "database/sql"
    "log"
    
    _ "github.com/microsoft/go-mssqldb"
)

func main() {
    db, err := sql.Open("sqlserver", "sqlserver://user:password@localhost:1433?database=mydb")
    if err != nil {
        log.Fatal(err)
    }
    defer db.Close()
    
    // Query example using positional parameters (@p1, @p2, etc.)
    rows, err := db.Query("SELECT @p1 AS Value", 42)
    if err != nil {
        log.Fatal(err)
    }
    defer rows.Close()
}
```

## Installation

```bash
go get github.com/microsoft/go-mssqldb
```

## Key Features

- Works with SQL Server 2005+, SQL database in Microsoft Fabric, and Azure SQL Database
- Supports Windows Authentication, SQL Authentication, Azure AD, Entra, and Kerberos
- Always Encrypted support
- Bulk copy operations
- Named pipes and shared memory connections on Windows
- Table-valued parameters
- Stored procedure support with output parameters

## Connection String Formats

### URL Format (Recommended)
```
sqlserver://username:password@host:port?database=mydb
sqlserver://username:password@host/instance?database=mydb
```

### ADO Format
```
server=localhost;user id=sa;password=secret;database=mydb
```

### ODBC Format
```
odbc:server=localhost;user id=sa;password=secret;database=mydb
```

## Azure SQL Database with Azure AD

```go
import (
    "database/sql"
    "github.com/microsoft/go-mssqldb/azuread"
)

func main() {
    // Enable TLS with certificate validation for Azure SQL
    db, err := sql.Open(azuread.DriverName, 
        "sqlserver://myserver.database.windows.net?database=mydb&fedauth=ActiveDirectoryDefault&encrypt=true&TrustServerCertificate=false")
}
```

## Driver Names

- `sqlserver` - Standard driver, use `@name` or `@p1` parameter syntax
- `azuresql` - Azure AD authentication support (import `azuread` package)
- `mssql` - Deprecated, uses `?` parameter syntax

## Common Patterns

### Query with Named Parameters
```go
db.QueryContext(ctx, "SELECT * FROM users WHERE id = @ID", sql.Named("ID", 123))
```

### Execute Stored Procedure
```go
var result int
db.ExecContext(ctx, "sp_MyProc", sql.Named("Input", "value"), sql.Named("Output", sql.Out{Dest: &result}))
```

### Bulk Insert
```go
import mssql "github.com/microsoft/go-mssqldb"

stmt, _ := db.Prepare(mssql.CopyIn("tablename", mssql.BulkOptions{}, "col1", "col2"))
stmt.Exec(val1, val2)
stmt.Exec() // Flush
```

## Documentation

- Full documentation: https://pkg.go.dev/github.com/microsoft/go-mssqldb
- README: https://github.com/microsoft/go-mssqldb/blob/main/README.md
- Examples: https://github.com/microsoft/go-mssqldb/tree/main/examples