forgejo/models/gitea_migrations/base/db.go
2025-10-14 14:40:49 -06:00

607 lines
22 KiB
Go

// Copyright 2022 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package base
import (
"errors"
"fmt"
"reflect"
"regexp"
"slices"
"strings"
"forgejo.org/models/db"
"forgejo.org/modules/log"
"forgejo.org/modules/setting"
"xorm.io/xorm"
"xorm.io/xorm/schemas"
)
// RecreateTables returns a function that will recreate the tables for the provided beans using the newly provided bean
// definition, move all data to the new tables, and then replace the original tables with a drop and rename.
//
// If any 'base' table is requested to be rebuilt where one-or-more 'satellite' tables exists that references it through
// a foreign key, you must rebuild the satellite tables as well or you will receive an error 'incomplete table set'.
//
// WARNING: YOU MUST PROVIDE THE FULL BEAN DEFINITION
func RecreateTables(beans ...any) func(*xorm.Engine) error {
return func(x *xorm.Engine) error {
sess := x.NewSession()
defer sess.Close()
if err := sess.Begin(); err != nil {
return err
}
sess = sess.StoreEngine("InnoDB")
tableNames := make(map[any]string, len(beans))
tempTableNames := make(map[any]string, len(beans))
tempTableNamesByOriginalName := make(map[string]string, len(beans))
for _, bean := range beans {
tableName := sess.Engine().TableName(bean)
tableNames[bean] = tableName
tempTableName := fmt.Sprintf("tmp_recreate__%s", tableName)
tempTableNames[bean] = tempTableName
tempTableNamesByOriginalName[tableName] = tempTableName
}
// Create a set of temp tables.
for _, bean := range beans {
log.Info("Creating temp table: %s for Bean: %s", tempTableNames[bean], reflect.Indirect(reflect.ValueOf(bean)).Type().Name())
if err := createTempTable(sess, bean, tempTableNames[bean]); err != nil {
return err
}
}
// Our new temp tables tables will have foreign keys that point to the original tables we are recreating.
// Before we put data into these tables, we need to drop those foreign keys and add new foreign keys that point
// to the temp tables.
tableSchemas := make(map[any]*schemas.Table, len(beans))
for _, bean := range beans {
tableSchema, err := sess.Engine().TableInfo(bean)
if err != nil {
log.Error("Unable to get table info. Error: %v", err)
return err
}
tableSchemas[bean] = tableSchema
modifications := make([]schemas.TableModification, 0, len(tableSchema.ForeignKeys)*2)
for _, fk := range tableSchema.ForeignKeys {
targetTempTableName, ok := tempTableNamesByOriginalName[fk.TargetTableName]
if !ok {
return fmt.Errorf("incomplete table set: Found a foreign key reference to table %s, but it is not included in RecreateTables", fk.TargetTableName)
}
fkName := fk.Name
if setting.Database.Type.IsMySQL() {
// See MySQL explanation in createTempTable.
fkName = "_" + fkName
}
modifications = append(modifications, schemas.DropForeignKey{ForeignKey: schemas.ForeignKey{
Name: fkName,
SourceFieldName: fk.SourceFieldName,
TargetTableName: fk.TargetTableName,
TargetFieldName: fk.TargetFieldName,
}})
modifications = append(modifications, schemas.AddForeignKey{ForeignKey: schemas.ForeignKey{
Name: fkName,
SourceFieldName: fk.SourceFieldName,
TargetTableName: targetTempTableName, // FK changed to new temp table
TargetFieldName: fk.TargetFieldName,
}})
}
if len(modifications) != 0 {
log.Info("Modifying temp table %s foreign keys to point to other temp tables", tempTableNames[bean])
if err := sess.Table(tempTableNames[bean]).AlterTable(bean, modifications...); err != nil {
return fmt.Errorf("alter table failed: while rewriting foreign keys to temp tables, error occurred: %w", err)
}
}
}
// Insert into the set of temp tables in the right order, starting with base tables, working outwards to
// satellite tables.
orderedBeans := slices.Clone(beans)
slices.SortFunc(orderedBeans, func(b1, b2 any) int {
return db.TableNameInsertionOrderSortFunc(tableNames[b1], tableNames[b2])
})
for _, bean := range orderedBeans {
log.Info("Copying table %s to temp table %s", tableNames[bean], tempTableNames[bean])
if err := copyData(sess, bean, tableNames[bean], tempTableNames[bean]); err != nil {
// copyData does its own logging
return err
}
}
// Drop all the old tables in the right order, starting with satellite tables working inwards to base tables,
// and rename all the temp tables to the final tables. The database will automatically update the foreign key
// references during the rename from temp to final tables.
for i := len(orderedBeans) - 1; i >= 0; i-- {
bean := orderedBeans[i]
log.Info("Dropping existing table %s, and renaming temp table %s in its place", tableNames[bean], tempTableNames[bean])
if err := renameTable(sess, bean, tableNames[bean], tempTableNames[bean], tableSchemas[bean]); err != nil {
// renameTable does its own logging
return err
}
}
return sess.Commit()
}
}
// LegacyRecreateTable 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
//
// Deprecated: LegacyRecreateTable exists for historical migrations and should not be used in current code -- tt does
// not support foreign key management. Use RecreateTables instead which provides foreign key support.
func LegacyRecreateTable(sess *xorm.Session, bean any) error {
tableName := sess.Engine().TableName(bean)
tempTableName := fmt.Sprintf("tmp_recreate__%s", tableName)
tableSchema, err := sess.Engine().TableInfo(bean)
if err != nil {
log.Error("Unable to get table info. Error: %v", err)
return err
}
// 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 := createTempTable(sess, bean, tempTableName); err != nil {
// createTempTable does its own logging
return err
}
if err := copyData(sess, bean, tableName, tempTableName); err != nil {
// copyData does its own logging
return err
}
if err := renameTable(sess, bean, tableName, tempTableName, tableSchema); err != nil {
// renameTable does its own logging
return err
}
return nil
}
func createTempTable(sess *xorm.Session, bean any, tempTableName string) error {
if setting.Database.Type.IsMySQL() {
// Can't have identical foreign key names in MySQL, and Table(tempTableName) only affects the table name and not
// the schema definition generated from the bean, so, we do a little adjusting by appending a `_` at the
// beginning of each foreign key name on the temp table. We'll remove this by renaming the constraint after we
// drop the original table, in renameTable.
originalTableSchema, err := sess.Engine().TableInfo(bean)
if err != nil {
log.Error("Unable to get table info. Error: %v", err)
return err
}
// `TableInfo()` will return a `*schema.Table` that is stored in a shared cache. We don't want to mutate that
// object as it will stick around and affect other things. Make a mostly-shallow clone, with a new slice for
// what we're changing.
tableSchema := *originalTableSchema
tableSchema.ForeignKeys = slices.Clone(originalTableSchema.ForeignKeys)
for i := range tableSchema.ForeignKeys {
tableSchema.ForeignKeys[i].Name = "_" + tableSchema.ForeignKeys[i].Name
}
sql, _, err := sess.Engine().Dialect().CreateTableSQL(&tableSchema, tempTableName)
if err != nil {
log.Error("Unable to generate CREATE TABLE query. Error: %v", err)
return err
}
_, err = sess.Exec(sql)
if err != nil {
log.Error("Unable to create table %s. Error: %v", tempTableName, err)
return err
}
} else {
if err := sess.Table(tempTableName).CreateTable(bean); err != nil {
log.Error("Unable to create table %s. Error: %v", tempTableName, err)
return err
}
}
if err := sess.Table(tempTableName).CreateUniques(bean); err != nil {
log.Error("Unable to create uniques for table %s. Error: %v", tempTableName, err)
return err
}
if err := sess.Table(tempTableName).CreateIndexes(bean); err != nil {
log.Error("Unable to create indexes for table %s. Error: %v", tempTableName, err)
return err
}
return nil
}
func copyData(sess *xorm.Session, bean any, tableName, tempTableName string) error {
// 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 {
log.Error("Unable to get table info. Error: %v", err)
return err
}
newTableColumns := table.Columns()
if len(newTableColumns) == 0 {
return errors.New("no columns in new table")
}
hasID := false
for _, column := range newTableColumns {
hasID = hasID || (column.IsPrimaryKey && column.IsAutoIncrement)
}
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 {
log.Error("Unable to set copy data in to temp table %s. Error: %v", tempTableName, err)
return err
}
return nil
}
func renameTable(sess *xorm.Session, bean any, tableName, tempTableName string, tableSchema *schemas.Table) error {
switch {
case setting.Database.Type.IsSQLite3():
if _, err := sess.Exec(fmt.Sprintf("DROP TABLE `%s`", tableName)); err != nil {
log.Error("Unable to drop old table %s. Error: %v", tableName, err)
return err
}
if err := sess.Table(tempTableName).DropIndexes(bean); err != nil {
log.Error("Unable to drop indexes on temporary table %s. Error: %v", tempTableName, err)
return err
}
if _, err := sess.Exec(fmt.Sprintf("ALTER TABLE `%s` RENAME TO `%s`", tempTableName, tableName)); err != nil {
log.Error("Unable to rename %s to %s. Error: %v", tempTableName, tableName, err)
return err
}
if err := sess.Table(tableName).CreateIndexes(bean); err != nil {
log.Error("Unable to recreate indexes on table %s. Error: %v", tableName, err)
return err
}
if err := sess.Table(tableName).CreateUniques(bean); err != nil {
log.Error("Unable to recreate uniques on table %s. Error: %v", tableName, err)
return err
}
case setting.Database.Type.IsMySQL():
if _, err := sess.Exec(fmt.Sprintf("DROP TABLE `%s`", tableName)); err != nil {
log.Error("Unable to drop old table %s. Error: %v", tableName, err)
return err
}
// MySQL will move all the constraints that reference this table from the temporary table to the new table
if _, err := sess.Exec(fmt.Sprintf("ALTER TABLE `%s` RENAME TO `%s`", tempTableName, tableName)); err != nil {
log.Error("Unable to rename %s to %s. Error: %v", tempTableName, tableName, err)
return err
}
// In `RecreateTables` the foreign keys were renamed with a '_' prefix to avoid conflicting on the original
// table's constraint names. Now that table has been dropped, so we can rename them back to leave the table in
// the right state. Unfortunately this will cause a recheck of the constraint's validity against the target
// table which will be slow for large tables, but it's unavoidable without the ability to rename constraints
// in-place. Awkwardly these FKs are still a reference to the tmp_recreate target table since we drop in reverse
// FK order -- the ALTER TABLE ... RENAME .. on those tmp tables will correct the FKs later.
modifications := make([]schemas.TableModification, 0, len(tableSchema.ForeignKeys)*2)
for _, fk := range tableSchema.ForeignKeys {
modifications = append(modifications, schemas.DropForeignKey{ForeignKey: schemas.ForeignKey{
Name: "_" + fk.Name,
SourceFieldName: fk.SourceFieldName,
TargetTableName: fmt.Sprintf("tmp_recreate__%s", fk.TargetTableName),
TargetFieldName: fk.TargetFieldName,
}})
modifications = append(modifications, schemas.AddForeignKey{ForeignKey: schemas.ForeignKey{
Name: fk.Name,
SourceFieldName: fk.SourceFieldName,
TargetTableName: fmt.Sprintf("tmp_recreate__%s", fk.TargetTableName),
TargetFieldName: fk.TargetFieldName,
}})
}
if len(modifications) != 0 {
if err := sess.Table(tableName).AlterTable(bean, modifications...); err != nil {
return fmt.Errorf("alter table failed: while rewriting foreign keys to original names, error occurred: %w", err)
}
}
case setting.Database.Type.IsPostgreSQL():
var originalSequences []string
type sequenceData struct {
LastValue int `xorm:"'last_value'"`
IsCalled bool `xorm:"'is_called'"`
}
sequenceMap := map[string]sequenceData{}
schema := sess.Engine().Dialect().URI().Schema
sess.Engine().SetSchema("")
if err := sess.Table("information_schema.sequences").Cols("sequence_name").Where("sequence_name LIKE ? || '_id_seq' AND sequence_catalog = ?", tableName, setting.Database.Name).Find(&originalSequences); err != nil {
log.Error("Unable to rename %s to %s. Error: %v", tempTableName, tableName, err)
return err
}
sess.Engine().SetSchema(schema)
for _, sequence := range originalSequences {
sequenceData := sequenceData{}
if _, err := sess.Table(sequence).Cols("last_value", "is_called").Get(&sequenceData); err != nil {
log.Error("Unable to get last_value and is_called from %s. Error: %v", sequence, err)
return err
}
sequenceMap[sequence] = sequenceData
}
// 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 {
log.Error("Unable to drop old table %s. Error: %v", tableName, err)
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 {
log.Error("Unable to rename %s to %s. Error: %v", tempTableName, tableName, err)
return err
}
var indices []string
sess.Engine().SetSchema("")
if err := sess.Table("pg_indexes").Cols("indexname").Where("tablename = ? ", tableName).Find(&indices); err != nil {
log.Error("Unable to rename %s to %s. Error: %v", tempTableName, tableName, err)
return err
}
sess.Engine().SetSchema(schema)
for _, index := range indices {
newIndexName := strings.Replace(index, "tmp_recreate__", "", 1)
if _, err := sess.Exec(fmt.Sprintf("ALTER INDEX `%s` RENAME TO `%s`", index, newIndexName)); err != nil {
log.Error("Unable to rename %s to %s. Error: %v", index, newIndexName, err)
return err
}
}
var sequences []string
sess.Engine().SetSchema("")
if err := sess.Table("information_schema.sequences").Cols("sequence_name").Where("sequence_name LIKE 'tmp_recreate__' || ? || '_id_seq' AND sequence_catalog = ?", tableName, setting.Database.Name).Find(&sequences); err != nil {
log.Error("Unable to rename %s to %s. Error: %v", tempTableName, tableName, err)
return err
}
sess.Engine().SetSchema(schema)
for _, sequence := range sequences {
newSequenceName := strings.Replace(sequence, "tmp_recreate__", "", 1)
if _, err := sess.Exec(fmt.Sprintf("ALTER SEQUENCE `%s` RENAME TO `%s`", sequence, newSequenceName)); err != nil {
log.Error("Unable to rename %s sequence to %s. Error: %v", sequence, newSequenceName, err)
return err
}
val, ok := sequenceMap[newSequenceName]
if newSequenceName == tableName+"_id_seq" {
if ok && val.LastValue != 0 {
if _, err := sess.Exec(fmt.Sprintf("SELECT setval('%s', %d, %t)", newSequenceName, val.LastValue, val.IsCalled)); err != nil {
log.Error("Unable to reset %s to %d. Error: %v", newSequenceName, val, err)
return err
}
} else {
// We're going to try to guess this
if _, err := sess.Exec(fmt.Sprintf("SELECT setval('%s', COALESCE((SELECT MAX(id)+1 FROM `%s`), 1), false)", newSequenceName, tableName)); err != nil {
log.Error("Unable to reset %s. Error: %v", newSequenceName, err)
return err
}
}
} else if ok {
if _, err := sess.Exec(fmt.Sprintf("SELECT setval('%s', %d, %t)", newSequenceName, val.LastValue, val.IsCalled)); err != nil {
log.Error("Unable to reset %s to %d. Error: %v", newSequenceName, val, err)
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
}
// TODO: This will not work if there are foreign keys
switch {
case setting.Database.Type.IsSQLite3():
// First drop the indexes on the columns
res, errIndex := sess.Query(fmt.Sprintf("PRAGMA index_list(`%s`)", tableName))
if errIndex != nil {
return errIndex
}
for _, row := range res {
indexName := row["name"]
indexRes, err := sess.Query(fmt.Sprintf("PRAGMA index_info(`%s`)", indexName))
if err != nil {
return err
}
if len(indexRes) != 1 {
continue
}
indexColumn := string(indexRes[0]["name"])
for _, name := range columnNames {
if name == indexColumn {
_, err := sess.Exec(fmt.Sprintf("DROP INDEX `%s`", indexName))
if err != nil {
return err
}
}
}
}
// Here we need to get the columns from the original table
sql := fmt.Sprintf("SELECT sql FROM sqlite_master WHERE tbl_name='%s' and type='table'", tableName)
res, err := sess.Query(sql)
if err != nil {
return err
}
tableSQL := string(res[0]["sql"])
// Get the string offset for column definitions: `CREATE TABLE ( column-definitions... )`
columnDefinitionsIndex := strings.Index(tableSQL, "(")
if columnDefinitionsIndex < 0 {
return errors.New("couldn't find column definitions")
}
// Separate out the column definitions
tableSQL = tableSQL[columnDefinitionsIndex:]
// Remove the required columnNames
for _, name := range columnNames {
tableSQL = regexp.MustCompile(regexp.QuoteMeta("`"+name+"`")+"[^`,)]*?[,)]").ReplaceAllString(tableSQL, "")
}
// Ensure the query is ended properly
tableSQL = strings.TrimSpace(tableSQL)
if tableSQL[len(tableSQL)-1] != ')' {
if tableSQL[len(tableSQL)-1] == ',' {
tableSQL = tableSQL[:len(tableSQL)-1]
}
tableSQL += ")"
}
// Find all the columns in the table
columns := regexp.MustCompile("`([^`]*)`").FindAllString(tableSQL, -1)
tableSQL = fmt.Sprintf("CREATE TABLE `new_%s_new` ", tableName) + tableSQL
if _, err := sess.Exec(tableSQL); err != nil {
return err
}
// Now restore the data
columnsSeparated := strings.Join(columns, ",")
insertSQL := fmt.Sprintf("INSERT INTO `new_%s_new` (%s) SELECT %s FROM %s", tableName, columnsSeparated, columnsSeparated, tableName)
if _, err := sess.Exec(insertSQL); err != nil {
return err
}
// Now drop the old table
if _, err := sess.Exec(fmt.Sprintf("DROP TABLE `%s`", tableName)); err != nil {
return err
}
// Rename the table
if _, err := sess.Exec(fmt.Sprintf("ALTER TABLE `new_%s_new` RENAME TO `%s`", tableName, tableName)); err != nil {
return err
}
case setting.Database.Type.IsPostgreSQL():
cols := ""
for _, col := range columnNames {
if cols != "" {
cols += ", "
}
cols += "DROP COLUMN `" + col + "` CASCADE"
}
if _, err := sess.Exec(fmt.Sprintf("ALTER TABLE `%s` %s", tableName, cols)); err != nil {
return fmt.Errorf("Drop table `%s` columns %v: %v", tableName, columnNames, err)
}
case setting.Database.Type.IsMySQL():
// Drop indexes on columns first
sql := fmt.Sprintf("SHOW INDEX FROM %s WHERE column_name IN ('%s')", tableName, strings.Join(columnNames, "','"))
res, err := sess.Query(sql)
if err != nil {
return err
}
for _, index := range res {
indexName := index["column_name"]
if len(indexName) > 0 {
_, err := sess.Exec(fmt.Sprintf("DROP INDEX `%s` ON `%s`", indexName, tableName))
if err != nil {
return err
}
}
}
// Now drop the columns
cols := ""
for _, col := range columnNames {
if cols != "" {
cols += ", "
}
cols += "DROP COLUMN `" + col + "`"
}
if _, err := sess.Exec(fmt.Sprintf("ALTER TABLE `%s` %s", tableName, cols)); err != nil {
return fmt.Errorf("Drop table `%s` columns %v: %v", tableName, columnNames, err)
}
default:
log.Fatal("Unrecognized DB")
}
return nil
}
// ModifyColumn will modify column's type or other property. SQLITE is not supported
func ModifyColumn(x *xorm.Engine, tableName string, col *schemas.Column) error {
var indexes map[string]*schemas.Index
var err error
defer func() {
for _, index := range indexes {
_, err = x.Exec(x.Dialect().CreateIndexSQL(tableName, index))
if err != nil {
log.Error("Create index %s on table %s failed: %v", index.Name, tableName, err)
}
}
}()
alterSQL := x.Dialect().ModifyColumnSQL(tableName, col)
if _, err := x.Exec(alterSQL); err != nil {
return err
}
return nil
}