Add command to convert mysql database from utf8 to utf8mb4 (#7144)

* add command to convert mysql database from utf8 to utf8mb4

* Update cmd/convert.go

Co-Authored-By: John Olheiser <42128690+jolheiser@users.noreply.github.com>

* Update cmd/convert.go

Co-Authored-By: John Olheiser <42128690+jolheiser@users.noreply.github.com>

* Update cmd/convert.go

Co-Authored-By: John Olheiser <42128690+jolheiser@users.noreply.github.com>

* Update models/convert.go

Co-Authored-By: John Olheiser <42128690+jolheiser@users.noreply.github.com>

* Update models/convert.go

Co-Authored-By: John Olheiser <42128690+jolheiser@users.noreply.github.com>

* Update cmd/convert.go

Co-Authored-By: John Olheiser <42128690+jolheiser@users.noreply.github.com>

* Update cmd/convert.go

Co-Authored-By: John Olheiser <42128690+jolheiser@users.noreply.github.com>

cmd/convert.go

@@ -0,0 +1,49 @@
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package cmd
+
+import (
+	"fmt"
+
+	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/setting"
+
+	"github.com/urfave/cli"
+)
+
+// CmdConvert represents the available convert sub-command.
+var CmdConvert = cli.Command{
+	Name:        "convert",
+	Usage:       "Convert the database",
+	Description: "A command to convert an existing MySQL database from utf8 to utf8mb4",
+	Action:      runConvert,
+}
+
+func runConvert(ctx *cli.Context) error {
+	if err := initDB(); err != nil {
+		return err
+	}
+
+	log.Trace("AppPath: %s", setting.AppPath)
+	log.Trace("AppWorkPath: %s", setting.AppWorkPath)
+	log.Trace("Custom path: %s", setting.CustomPath)
+	log.Trace("Log path: %s", setting.LogRootPath)
+	models.LoadConfigs()
+
+	if models.DbCfg.Type != "mysql" {
+		fmt.Println("This command can only be used with a MySQL database")
+		return nil
+	}
+
+	if err := models.ConvertUtf8ToUtf8mb4(); err != nil {
+		log.Fatal("Failed to convert database from utf8 to utf8mb4: %v", err)
+		return err
+	}
+
+	fmt.Println("Converted successfully, please confirm your database's character set is now utf8mb4")
+
+	return nil
+}

main.go

@@ -67,6 +67,7 @@ arguments - which can alternatively be run by running the subcommand web.`
 		cmd.CmdGenerate,
 		cmd.CmdMigrate,
 		cmd.CmdKeys,
+		cmd.CmdConvert,
 	}
 	// Now adjust these commands to add our global configuration options
 

models/convert.go

@@ -0,0 +1,27 @@
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package models
+
+import "fmt"
+
+// ConvertUtf8ToUtf8mb4 converts database and tables from utf8 to utf8mb4 if it's mysql
+func ConvertUtf8ToUtf8mb4() error {
+	_, err := x.Exec(fmt.Sprintf("ALTER DATABASE `%s` CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci", DbCfg.Name))
+	if err != nil {
+		return err
+	}
+
+	tables, err := x.DBMetas()
+	if err != nil {
+		return err
+	}
+	for _, table := range tables {
+		if _, err := x.Exec(fmt.Sprintf("ALTER TABLE `%s` CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci;", table.Name)); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}