Create database package (refactoring)

database/migration.go

@@ -0,0 +1,55 @@
+// Copyright 2018 Frédéric Guillot. All rights reserved.
+// Use of this source code is governed by the Apache 2.0
+// license that can be found in the LICENSE file.
+
+package database
+
+import (
+	"database/sql"
+	"fmt"
+	"strconv"
+
+	"github.com/miniflux/miniflux/logger"
+)
+
+const schemaVersion = 20
+
+// Migrate executes database migrations.
+func Migrate(db *sql.DB) {
+	var currentVersion int
+	db.QueryRow(`select version from schema_version`).Scan(&currentVersion)
+
+	fmt.Println("Current schema version:", currentVersion)
+	fmt.Println("Latest schema version:", schemaVersion)
+
+	for version := currentVersion + 1; version <= schemaVersion; version++ {
+		fmt.Println("Migrating to version:", version)
+
+		tx, err := db.Begin()
+		if err != nil {
+			logger.Fatal("[Migrate] %v", err)
+		}
+
+		rawSQL := SqlMap["schema_version_"+strconv.Itoa(version)]
+		// fmt.Println(rawSQL)
+		_, err = tx.Exec(rawSQL)
+		if err != nil {
+			tx.Rollback()
+			logger.Fatal("[Migrate] %v", err)
+		}
+
+		if _, err := tx.Exec(`delete from schema_version`); err != nil {
+			tx.Rollback()
+			logger.Fatal("[Migrate] %v", err)
+		}
+
+		if _, err := tx.Exec(`insert into schema_version (version) values($1)`, version); err != nil {
+			tx.Rollback()
+			logger.Fatal("[Migrate] %v", err)
+		}
+
+		if err := tx.Commit(); err != nil {
+			logger.Fatal("[Migrate] %v", err)
+		}
+	}
+}