Add command to recreate tables

cmd/doctor.go

@@ -61,6 +61,21 @@ var CmdDoctor = cli.Command{
 			Usage: `Name of the log file (default: "doctor.log"). Set to "-" to output to stdout, set to "" to disable`,
 		},
 	},
+	Subcommands: []cli.Command{
+		cmdRecreateTable,
+	},
+}
+
+var cmdRecreateTable = cli.Command{
+	Name:      "recreate-table",
+	Usage:     "Recreate tables from XORM definitions and copy the data.",
+	ArgsUsage: "[TABLE]... : (TABLEs to recreate - leave blank for all)",
+	Description: `The database definitions Gitea uses change across versions, sometimes changing default values and leaving old unused columns.
+
+This command will cause Xorm to recreate tables, copying over the data and deleting the old table.
+
+You should back-up your database before doing this and ensure that your database is up-to-date first.`,
+	Action: runRecreateTable,
 }
 
 type check struct {
@@ -129,6 +144,37 @@ var checklist = []check{
 	// more checks please append here
 }
 
+func runRecreateTable(ctx *cli.Context) error {
+	// Redirect the default golog to here
+	golog.SetFlags(0)
+	golog.SetPrefix("")
+	golog.SetOutput(log.NewLoggerAsWriter("INFO", log.GetLogger(log.DEFAULT)))
+
+	setting.EnableXORMLog = false
+	if err := initDBDisableConsole(true); err != nil {
+		fmt.Println(err)
+		fmt.Println("Check if you are using the right config file. You can use a --config directive to specify one.")
+		return nil
+	}
+
+	if err := models.NewEngine(context.Background(), migrations.EnsureUpToDate); err != nil {
+		return err
+	}
+
+	args := ctx.Args()
+	names := make([]string, 0, ctx.NArg())
+	for i := 0; i < ctx.NArg(); i++ {
+		names = append(names, args.Get(i))
+	}
+
+	beans, err := models.NamesToBean(names...)
+	if err != nil {
+		return err
+	}
+
+	return models.NewEngine(context.Background(), migrations.RecreateTables(beans...))
+}
+
 func runDoctor(ctx *cli.Context) error {
 
 	// Silence the default loggers

docs/content/doc/usage/command-line.en-us.md

@@ -319,6 +319,36 @@ var checklist = []check{
 
 This function will receive a command line context and return a list of details about the problems or error.
 
+##### doctor recreate-table
+
+Sometimes when there are migrations the old columns and default values may be left
+unchanged in the database schema. This may lead to warning such as:
+
+```
+2020/08/02 11:32:29 ...rm/session_schema.go:360:Sync2() [W] Table user Column keep_activity_private db default is , struct default is 0
+```
+
+You can cause Gitea to recreate these tables and copy the old data into the new table
+with the defaults set appropriately by using:
+
+```
+gitea doctor recreate-table user
+```
+
+You can ask gitea to recreate multiple tables using:
+
+```
+gitea doctor recreate-table table1 table2 ...
+```
+
+And if you would like Gitea to recreate all tables simply call:
+
+```
+gitea doctor recreate-table
+```
+
+It is highly recommended to back-up your database before running these commands.
+
 #### manager
 
 Manage running server operations:

integrations/migration-test/migration_test.go

@@ -257,6 +257,19 @@ func doMigrationTest(t *testing.T, version string) {
 	err = models.NewEngine(context.Background(), wrappedMigrate)
 	assert.NoError(t, err)
 	currentEngine.Close()
+
+	err = models.SetEngine()
+	assert.NoError(t, err)
+
+	beans, _ := models.NamesToBean()
+
+	err = models.NewEngine(context.Background(), func(x *xorm.Engine) error {
+		currentEngine = x
+		return migrations.RecreateTables(beans...)(x)
+	})
+	assert.NoError(t, err)
+
+	currentEngine.Close()
 }
 
 func TestMigrations(t *testing.T) {

models/migrations/migrations.go

@@ -7,6 +7,7 @@ package migrations
 
 import (
 	"fmt"
+	"reflect"
 	"regexp"
 	"strings"
 
@@ -317,6 +318,147 @@ Please try upgrading to a lower version first (suggested v1.6.4), then upgrade t
 	return nil
 }
 
+// RecreateTables will recreate the tables for the provided beans using the newly provided bean definition and move all data to that new table
+// WARNING: YOU MUST PROVIDE THE FULL BEAN DEFINITION
+func RecreateTables(beans ...interface{}) func(*xorm.Engine) error {
+	return func(x *xorm.Engine) error {
+		sess := x.NewSession()
+		defer sess.Close()
+		if err := sess.Begin(); err != nil {
+			return err
+		}
+		for _, bean := range beans {
+			log.Info("Recreating Table: %s for Bean: %s", x.TableName(bean), reflect.Indirect(reflect.ValueOf(bean)).Type().Name())
+			if err := recreateTable(sess, bean); err != nil {
+				return err
+			}
+		}
+		return sess.Commit()
+	}
+}
+
+// recreateTable will recreate the table using the newly provided bean definition and move all data to that new table
+// WARNING: YOU MUST PROVIDE THE FULL BEAN DEFINITION
+// WARNING: YOU MUST COMMIT THE SESSION AT THE END
+func recreateTable(sess *xorm.Session, bean interface{}) error {
+	// TODO: This will not work if there are foreign keys
+
+	tableName := sess.Engine().TableName(bean)
+	tempTableName := fmt.Sprintf("tempzzz_%s_zzztemp", tableName)
+
+	// We need to move the old table away and create a new one with the correct columns
+	// We will need to do this in stages to prevent data loss
+	//
+	// First create the temporary table
+	if err := sess.Table(tempTableName).CreateTable(bean); err != nil {
+		return err
+	}
+
+	// Work out the column names from the bean - these are the columns to select from the old table and install into the new table
+	table, err := sess.Engine().TableInfo(bean)
+	if err != nil {
+		return err
+	}
+	newTableColumns := table.Columns()
+	if len(newTableColumns) == 0 {
+		return fmt.Errorf("no columns in new table")
+	}
+
+	if setting.Database.UseMSSQL {
+		sess.Exec(fmt.Sprintf("SET IDENTITY_INSERT %s ON", tempTableName))
+	}
+
+	sqlStringBuilder := &strings.Builder{}
+	_, _ = sqlStringBuilder.WriteString("INSERT INTO ")
+	_, _ = sqlStringBuilder.WriteString(tempTableName)
+	_, _ = sqlStringBuilder.WriteString(" (`")
+	_, _ = sqlStringBuilder.WriteString(newTableColumns[0].Name)
+	_, _ = sqlStringBuilder.WriteString("`")
+	for _, column := range newTableColumns[1:] {
+		_, _ = sqlStringBuilder.WriteString(", `")
+		_, _ = sqlStringBuilder.WriteString(column.Name)
+		_, _ = sqlStringBuilder.WriteString("`")
+	}
+	_, _ = sqlStringBuilder.WriteString(")")
+	_, _ = sqlStringBuilder.WriteString(" SELECT ")
+	if newTableColumns[0].Default != "" {
+		_, _ = sqlStringBuilder.WriteString("COALESCE(`")
+		_, _ = sqlStringBuilder.WriteString(newTableColumns[0].Name)
+		_, _ = sqlStringBuilder.WriteString("`, ")
+		_, _ = sqlStringBuilder.WriteString(newTableColumns[0].Default)
+		_, _ = sqlStringBuilder.WriteString(")")
+	} else {
+		_, _ = sqlStringBuilder.WriteString("`")
+		_, _ = sqlStringBuilder.WriteString(newTableColumns[0].Name)
+		_, _ = sqlStringBuilder.WriteString("`")
+	}
+
+	for _, column := range newTableColumns[1:] {
+		if column.Default != "" {
+			_, _ = sqlStringBuilder.WriteString(", COALESCE(`")
+			_, _ = sqlStringBuilder.WriteString(column.Name)
+			_, _ = sqlStringBuilder.WriteString("`, ")
+			_, _ = sqlStringBuilder.WriteString(column.Default)
+			_, _ = sqlStringBuilder.WriteString(")")
+		} else {
+			_, _ = sqlStringBuilder.WriteString(", `")
+			_, _ = sqlStringBuilder.WriteString(column.Name)
+			_, _ = sqlStringBuilder.WriteString("`")
+		}
+	}
+	_, _ = sqlStringBuilder.WriteString(" FROM `")
+	_, _ = sqlStringBuilder.WriteString(tableName)
+	_, _ = sqlStringBuilder.WriteString("`")
+
+	if _, err := sess.Exec(sqlStringBuilder.String()); err != nil {
+		return err
+	}
+
+	if setting.Database.UseMSSQL {
+		sess.Exec(fmt.Sprintf("SET IDENTITY_INSERT %s OFF", tempTableName))
+	}
+
+	switch {
+	case setting.Database.UseSQLite3:
+		fallthrough
+	case setting.Database.UseMySQL:
+		// SQLite and MySQL will drop all the constraints on the old table
+		if _, err := sess.Exec(fmt.Sprintf("DROP TABLE `%s`", tableName)); err != nil {
+			return err
+		}
+
+		// SQLite and MySQL will move all the constraints from the temporary table to the new table
+		if _, err := sess.Exec(fmt.Sprintf("ALTER TABLE `%s` RENAME TO `%s`", tempTableName, tableName)); err != nil {
+			return err
+		}
+	case setting.Database.UsePostgreSQL:
+		// CASCADE causes postgres to drop all the constraints on the old table
+		if _, err := sess.Exec(fmt.Sprintf("DROP TABLE `%s` CASCADE", tableName)); err != nil {
+			return err
+		}
+
+		// CASCADE causes postgres to move all the constraints from the temporary table to the new table
+		if _, err := sess.Exec(fmt.Sprintf("ALTER TABLE `%s` RENAME TO `%s`", tempTableName, tableName)); err != nil {
+			return err
+		}
+	case setting.Database.UseMSSQL:
+		// MSSQL will drop all the constraints on the old table
+		if _, err := sess.Exec(fmt.Sprintf("DROP TABLE `%s`", tableName)); err != nil {
+			return err
+		}
+
+		// MSSQL sp_rename will move all the constraints from the temporary table to the new table
+		if _, err := sess.Exec(fmt.Sprintf("sp_rename '[%s]','[%s]'", tempTableName, tableName)); err != nil {
+			return err
+		}
+
+	default:
+		log.Fatal("Unrecognized DB")
+	}
+	return nil
+}
+
+// WARNING: YOU MUST COMMIT THE SESSION AT THE END
 func dropTableColumns(sess *xorm.Session, tableName string, columnNames ...string) (err error) {
 	if tableName == "" || len(columnNames) == 0 {
 		return nil
@@ -465,7 +607,6 @@ func dropTableColumns(sess *xorm.Session, tableName string, columnNames ...strin
 			return fmt.Errorf("Drop table `%s` columns %v: %v", tableName, columnNames, err)
 		}
 
-		return sess.Commit()
 	default:
 		log.Fatal("Unrecognized DB")
 	}

models/migrations/v102.go

@@ -11,5 +11,8 @@ import (
 func dropColumnHeadUserNameOnPullRequest(x *xorm.Engine) error {
 	sess := x.NewSession()
 	defer sess.Close()
-	return dropTableColumns(sess, "pull_request", "head_user_name")
+	if err := dropTableColumns(sess, "pull_request", "head_user_name"); err != nil {
+		return err
+	}
+	return sess.Commit()
 }

models/models.go

@@ -10,6 +10,8 @@ import (
 	"database/sql"
 	"errors"
 	"fmt"
+	"reflect"
+	"strings"
 
 	"code.gitea.io/gitea/modules/setting"
 
@@ -210,6 +212,36 @@ func NewEngine(ctx context.Context, migrateFunc func(*xorm.Engine) error) (err e
 	return nil
 }
 
+// NamesToBean return a list of beans or an error
+func NamesToBean(names ...string) ([]interface{}, error) {
+	beans := []interface{}{}
+	if len(names) == 0 {
+		beans = append(beans, tables...)
+		return beans, nil
+	}
+	// Need to map provided names to beans...
+	beanMap := make(map[string]interface{})
+	for _, bean := range tables {
+
+		beanMap[strings.ToLower(reflect.Indirect(reflect.ValueOf(bean)).Type().Name())] = bean
+		beanMap[strings.ToLower(x.TableName(bean))] = bean
+		beanMap[strings.ToLower(x.TableName(bean, true))] = bean
+	}
+
+	gotBean := make(map[interface{}]bool)
+	for _, name := range names {
+		bean, ok := beanMap[strings.ToLower(strings.TrimSpace(name))]
+		if !ok {
+			return nil, fmt.Errorf("No table found that matches: %s", name)
+		}
+		if !gotBean[bean] {
+			beans = append(beans, bean)
+			gotBean[bean] = true
+		}
+	}
+	return beans, nil
+}
+
 // Statistic contains the database statistics
 type Statistic struct {
 	Counter struct {