Merge pull request #21 from divoxx/mysql_version_table_issue

WIP: Prevents MySQL driver to failing when version table alredy exists

driver/mysql/mysql.go

@@ -50,9 +50,12 @@ func (driver *Driver) Close() error {
 }
 
 func (driver *Driver) ensureVersionTableExists() error {
-	if _, err := driver.db.Exec("CREATE TABLE IF NOT EXISTS " + tableName + " (version int not null primary key);"); err != nil {
+	_, err := driver.db.Exec("CREATE TABLE IF NOT EXISTS " + tableName + " (version int not null primary key);")
+
+	if _, isWarn := err.(mysql.MySQLWarnings); err != nil && !isWarn {
 		return err
 	}
+
 	return nil
 }
 
@@ -100,54 +103,58 @@ func (driver *Driver) Migrate(f file.File, pipe chan interface{}) {
 	sqlStmts := bytes.Split(f.Content, []byte(";"))
 
 	for _, sqlStmt := range sqlStmts {
-		if len(bytes.TrimSpace(sqlStmt)) > 0 {
+		sqlStmt = bytes.TrimSpace(sqlStmt)
+		if len(sqlStmt) > 0 {
 			if _, err := tx.Exec(string(sqlStmt)); err != nil {
-				mysqlErr := err.(*mysql.MySQLError)
+				mysqlErr, isErr := err.(*mysql.MySQLError)
+
+				if isErr {
+					re, err := regexp.Compile(`at line ([0-9]+)$`)
+					if err != nil {
+						pipe <- err
+						if err := tx.Rollback(); err != nil {
+							pipe <- err
+						}
+					}
+
+					var lineNo int
+					lineNoRe := re.FindStringSubmatch(mysqlErr.Message)
+					if len(lineNoRe) == 2 {
+						lineNo, err = strconv.Atoi(lineNoRe[1])
+					}
+					if err == nil {
+
+						// get white-space offset
+						// TODO this is broken, because we use sqlStmt instead of f.Content
+						wsLineOffset := 0
+						b := bufio.NewReader(bytes.NewBuffer(sqlStmt))
+						for {
+							line, _, err := b.ReadLine()
+							if err != nil {
+								break
+							}
+							if bytes.TrimSpace(line) == nil {
+								wsLineOffset += 1
+							} else {
+								break
+							}
+						}
+
+						message := mysqlErr.Error()
+						message = re.ReplaceAllString(message, fmt.Sprintf("at line %v", lineNo+wsLineOffset))
+
+						errorPart := file.LinesBeforeAndAfter(sqlStmt, lineNo, 5, 5, true)
+						pipe <- errors.New(fmt.Sprintf("%s\n\n%s", message, string(errorPart)))
+					} else {
+						pipe <- errors.New(mysqlErr.Error())
+					}
 
-				re, err := regexp.Compile(`at line ([0-9]+)$`)
-				if err != nil {
-					pipe <- err
 					if err := tx.Rollback(); err != nil {
 						pipe <- err
 					}
+
+					return
 				}
-
-				var lineNo int
-				lineNoRe := re.FindStringSubmatch(mysqlErr.Message)
-				if len(lineNoRe) == 2 {
-					lineNo, err = strconv.Atoi(lineNoRe[1])
-				}
-				if err == nil {
-
-					// get white-space offset
-					// TODO this is broken, because we use sqlStmt instead of f.Content
-					wsLineOffset := 0
-					b := bufio.NewReader(bytes.NewBuffer(sqlStmt))
-					for {
-						line, _, err := b.ReadLine()
-						if err != nil {
-							break
-						}
-						if bytes.TrimSpace(line) == nil {
-							wsLineOffset += 1
-						} else {
-							break
-						}
-					}
-
-					message := mysqlErr.Error()
-					message = re.ReplaceAllString(message, fmt.Sprintf("at line %v", lineNo+wsLineOffset))
-
-					errorPart := file.LinesBeforeAndAfter(sqlStmt, lineNo, 5, 5, true)
-					pipe <- errors.New(fmt.Sprintf("%s\n\n%s", message, string(errorPart)))
-				} else {
-					pipe <- errors.New(mysqlErr.Error())
-				}
-
-				if err := tx.Rollback(); err != nil {
-					pipe <- err
-				}
-				return
 			}
 		}
 	}