connection func and example

database.go

@@ -12,6 +12,7 @@ import (
 var (
 	ErrNoResults        = errors.New("no results found") // ErrNoResults indicates query found no results
 	ErrInvalidTableName = errors.New("invalid table")    // ErrInvalidTableName indicates that specified table does not exist
+	ErrNoConnection     = errors.New("no db connection") //
 	db                  *bbolt.DB
 )
 
@@ -30,6 +31,11 @@ func Close() error {
 	return db.Close()
 }
 
+// Connection returns the connection to the store for more advanced queries by caller
+func Connection() *bbolt.DB {
+	return db
+}
+
 func createTables(tables []string) error {
 	var errs error
 	for _, table := range tables {

example_test.go

@@ -0,0 +1,54 @@
+package boltdb_test
+
+import (
+	"encoding/json"
+	"fmt"
+
+	"github.com/devilcove/boltdb"
+	"go.etcd.io/bbolt"
+)
+
+const UserTable = "users"
+
+type User struct {
+	UserName string
+	Password string
+	IsAdmin  bool
+}
+
+func ExampleConnection() {
+	if AdminExists() {
+		fmt.Println("admin exists")
+	} else {
+		fmt.Println("admin does not exist")
+	}
+	// Output: admin does not exist
+}
+
+func AdminExists() bool {
+	var user User
+	var found bool
+	db := boltdb.Connection()
+	if db == nil {
+		return found
+	}
+	if err := db.View(func(tx *bbolt.Tx) error {
+		b := tx.Bucket([]byte(UserTable))
+		if b == nil {
+			return boltdb.ErrNoResults
+		}
+		_ = b.ForEach(func(k, v []byte) error {
+			if err := json.Unmarshal(v, &user); err != nil {
+				return err
+			}
+			if user.IsAdmin {
+				found = true
+			}
+			return nil
+		})
+		return nil
+	}); err != nil {
+		return false
+	}
+	return found
+}