Microsoft SQL Server driver and prep

vendor/github.com/denisenkom/go-mssqldb/uniqueidentifier.go

@@ -0,0 +1,74 @@
+package mssql
+
+import (
+	"database/sql/driver"
+	"encoding/hex"
+	"errors"
+	"fmt"
+)
+
+type UniqueIdentifier [16]byte
+
+func (u *UniqueIdentifier) Scan(v interface{}) error {
+	reverse := func(b []byte) {
+		for i, j := 0, len(b)-1; i < j; i, j = i+1, j-1 {
+			b[i], b[j] = b[j], b[i]
+		}
+	}
+
+	switch vt := v.(type) {
+	case []byte:
+		if len(vt) != 16 {
+			return errors.New("mssql: invalid UniqueIdentifier length")
+		}
+
+		var raw UniqueIdentifier
+
+		copy(raw[:], vt)
+
+		reverse(raw[0:4])
+		reverse(raw[4:6])
+		reverse(raw[6:8])
+		*u = raw
+
+		return nil
+	case string:
+		if len(vt) != 36 {
+			return errors.New("mssql: invalid UniqueIdentifier string length")
+		}
+
+		b := []byte(vt)
+		for i, c := range b {
+			switch c {
+			case '-':
+				b = append(b[:i], b[i+1:]...)
+			}
+		}
+
+		_, err := hex.Decode(u[:], []byte(b))
+		return err
+	default:
+		return fmt.Errorf("mssql: cannot convert %T to UniqueIdentifier", v)
+	}
+}
+
+func (u UniqueIdentifier) Value() (driver.Value, error) {
+	reverse := func(b []byte) {
+		for i, j := 0, len(b)-1; i < j; i, j = i+1, j-1 {
+			b[i], b[j] = b[j], b[i]
+		}
+	}
+
+	raw := make([]byte, len(u))
+	copy(raw, u[:])
+
+	reverse(raw[0:4])
+	reverse(raw[4:6])
+	reverse(raw[6:8])
+
+	return raw, nil
+}
+
+func (u UniqueIdentifier) String() string {
+	return fmt.Sprintf("%X-%X-%X-%X-%X", u[0:4], u[4:6], u[6:8], u[8:10], u[10:])
+}