Made the db connection check the migration version and fail on mismatch

db/connection.go

@@ -3,6 +3,7 @@ package db
 import (
 	"database/sql"
 	"fmt"
+	"strconv"
 
 	"github.com/pkg/errors"
 	"github.com/rs/zerolog"
@@ -11,12 +12,46 @@ import (
 )
 
 // Returns a database connection handle for the DB
-func ConnectToDatabase(dbName string, logger *zerolog.Logger) (*SafeConn, error) {
+func ConnectToDatabase(
+	dbName string,
+	logger *zerolog.Logger,
+) (*SafeConn, error) {
 	file := fmt.Sprintf("file:%s.db", dbName)
 	db, err := sql.Open("sqlite", file)
 	if err != nil {
 		return nil, errors.Wrap(err, "sql.Open")
 	}
+	version, err := strconv.Atoi(dbName)
+	if err != nil {
+		return nil, errors.Wrap(err, "strconv.Atoi")
+	}
+	err = checkDBVersion(db, version)
+	if err != nil {
+		return nil, errors.Wrap(err, "checkDBVersion")
+	}
 	conn := MakeSafe(db, logger)
 	return conn, nil
 }
+
+// Check the database version
+func checkDBVersion(db *sql.DB, expectVer int) error {
+	query := `SELECT version_id FROM goose_db_version WHERE is_applied = 1
+    ORDER BY version_id DESC LIMIT 1`
+	rows, err := db.Query(query)
+	if err != nil {
+		return errors.Wrap(err, "checkDBVersion")
+	}
+	if rows.Next() {
+		var version int
+		err = rows.Scan(&version)
+		if err != nil {
+			return errors.Wrap(err, "rows.Scan")
+		}
+		if version != expectVer {
+			return errors.New("Version mismatch")
+		}
+	} else {
+		return errors.New("No version found")
+	}
+	return nil
+}