fix create/drop view bug (#100)

Co-authored-by: walter <[email protected]>

pkg/ccr/base/spec.go

@@ -297,6 +297,67 @@ func (s *Spec) GetAllTables() ([]string, error) {
 	return tables, nil
 }
 
+func (s *Spec) queryResult(querySQL string, queryColumn string, errMsg string) ([]string, error) {
+	db, err := s.ConnectDB()
+	if err != nil {
+		return nil, err
+	}
+
+	rows, err := db.Query(querySQL)
+	if err != nil {
+		return nil, xerror.Wrap(err, xerror.Normal, querySQL+" failed")
+	}
+	defer rows.Close()
+
+	var results []string
+	for rows.Next() {
+		rowParser := utils.NewRowParser()
+		if err := rowParser.Parse(rows); err != nil {
+			return nil, xerror.Wrap(err, xerror.Normal, errMsg)
+		}
+		result, err := rowParser.GetString(queryColumn)
+		if err != nil {
+			return nil, xerror.Wrap(err, xerror.Normal, errMsg)
+		}
+		results = append(results, result)
+	}
+
+	return results, nil
+}
+
+func (s *Spec) GetAllViewsFromTable(tableName string) ([]string, error) {
+	log.Debugf("get all view from table %s", tableName)
+
+	var results []string
+	// first, query information_schema.tables with table_schema and table_type, get all views' name
+	querySql := fmt.Sprintf("SELECT table_name FROM information_schema.tables WHERE table_schema = '%s' AND  table_type = 'VIEW'", s.Database)
+	viewsFromQuery, err := s.queryResult(querySql, "table_name", "QUERY VIEWS")
+	if err != nil {
+		return nil, xerror.Wrap(err, xerror.Normal, "query views from information schema failed")
+	}
+
+	// then query view's create sql, if create sql contains tableName, this view is wanted
+	viewRegex := regexp.MustCompile("`internal`.`(\\w+)`.`" + strings.TrimSpace(tableName) + "`")
+	for _, eachViewName := range viewsFromQuery {
+		showCreateViewSql := fmt.Sprintf("SHOW CREATE VIEW %s", eachViewName)
+		createViewSqlList, err := s.queryResult(showCreateViewSql, "Create View", "SHOW CREATE VIEW")
+		if err != nil {
+			return nil, xerror.Wrap(err, xerror.Normal, "show create view failed")
+		}
+
+		// a view has only one create sql, so use createViewSqlList[0] as the only sql
+		if len(createViewSqlList) > 0 {
+			found := viewRegex.MatchString(createViewSqlList[0])
+			if found {
+				results = append(results, eachViewName)
+			}
+		}
+	}
+
+	log.Debugf("get view result is %s", results)
+	return results, nil
+}
+
 func (s *Spec) dropTable(table string) error {
 	log.Infof("drop table %s.%s", s.Database, table)
 
@@ -354,6 +415,28 @@ func (s *Spec) CreateTable(createTable *record.CreateTable) error {
 	return s.DbExec(sql)
 }
 
+func (s *Spec) CreateTableOrView(createTable *record.CreateTable, srcDatabase string) error {
+	//	Creating table will only occur when sync db.
+	//	When create view, the db name of sql is source db name, we should use dest db name to create view
+	createSql := createTable.Sql
+	viewRegex := regexp.MustCompile("(?i)^CREATE(\\s+)VIEW")
+	isCreateView := viewRegex.MatchString(createSql)
+	if isCreateView {
+		log.Debugf("create view, use dest db name to replace source db name")
+
+		// replace `internal`.`source_db_name`. to `internal`.`dest_db_name`.
+		originalName := "`internal`.`" + strings.TrimSpace(srcDatabase) + "`."
+		replaceName := "`internal`.`" + strings.TrimSpace(s.Database) + "`."
+		createTable.Sql = strings.ReplaceAll(createTable.Sql, originalName, replaceName)
+		log.Debugf("original create view sql is %s, after repalce, now sql is %s", createSql, createTable.Sql)
+	}
+
+	sql := createTable.Sql
+	log.Infof("createTableSql: %s", sql)
+	// HACK: for drop table
+	return s.DbExec(sql)
+}
+
 func (s *Spec) CheckDatabaseExists() (bool, error) {
 	log.Debugf("check database exist by spec: %s", s.String())
 	db, err := s.Connect()
@@ -787,6 +870,12 @@ func (s *Spec) DropTable(tableName string) error {
 	return s.DbExec(dropSql)
 }
 
+func (s *Spec) DropView(viewName string) error {
+	dropView := fmt.Sprintf("DROP VIEW IF EXISTS %s ", utils.FormatKeywordName(viewName))
+	log.Infof("drop view sql: %s", dropView)
+	return s.DbExec(dropView)
+}
+
 func (s *Spec) AddPartition(destTableName string, addPartition *record.AddPartition) error {
 	addPartitionSql := addPartition.GetSql(destTableName)
 	addPartitionSql = correctAddPartitionSql(addPartitionSql, addPartition)

pkg/ccr/base/specer.go

@@ -18,9 +18,11 @@ type Specer interface {
 	IsDatabaseEnableBinlog() (bool, error)
 	IsTableEnableBinlog() (bool, error)
 	GetAllTables() ([]string, error)
+	GetAllViewsFromTable(tableName string) ([]string, error)
 	ClearDB() error
 	CreateDatabase() error
 	CreateTable(createTable *record.CreateTable) error
+	CreateTableOrView(createTable *record.CreateTable, srcDatabase string) error
 	CheckDatabaseExists() (bool, error)
 	CheckTableExists() (bool, error)
 	CreateSnapshotAndWaitForDone(tables []string) (string, error)
@@ -31,6 +33,7 @@ type Specer interface {
 	LightningSchemaChange(srcDatabase string, changes *record.ModifyTableAddOrDropColumns) error
 	TruncateTable(destTableName string, truncateTable *record.TruncateTable) error
 	DropTable(tableName string) error
+	DropView(viewName string) error
 
 	AddPartition(destTableName string, addPartition *record.AddPartition) error
 	DropPartition(destTableName string, dropPartition *record.DropPartition) error

pkg/ccr/job.go

@@ -946,7 +946,7 @@ func (j *Job) handleCreateTable(binlog *festruct.TBinlog) error {
 		return err
 	}
 
-	if err := j.IDest.CreateTable(createTable); err != nil {
+	if err := j.IDest.CreateTableOrView(createTable, j.Src.Database); err != nil {
 		return xerror.Wrapf(err, xerror.Normal, "create table %d", createTable.TableId)
 	}
 
@@ -1034,14 +1034,38 @@ func (j *Job) handleAlterJob(binlog *festruct.TBinlog) error {
 		return nil
 	}
 
+	// drop table dropTableSql
+	var destTableName string
+	if j.SyncType == TableSync {
+		destTableName = j.Dest.Table
+	} else {
+		destTableName = alterJob.TableName
+	}
+
+	var allViewDeleted bool = false
 	for {
-		// drop table dropTableSql
-		var destTableName string
-		if j.SyncType == TableSync {
-			destTableName = j.Dest.Table
-		} else {
-			destTableName = alterJob.TableName
+		// before drop table, drop related view firstly
+		if !allViewDeleted {
+			views, err := j.IDest.GetAllViewsFromTable(destTableName)
+			if err != nil {
+				log.Errorf("when alter job, get view from table failed, err : %v", err)
+				continue
+			}
+
+			var dropViewFailed bool = false
+			for _, view := range views {
+				if err := j.IDest.DropView(view); err != nil {
+					log.Errorf("when alter job, drop view %s failed, err : %v", view, err)
+					dropViewFailed = true
+				}
+			}
+			if dropViewFailed {
+				continue
+			}
+
+			allViewDeleted = true
 		}
+
 		if err := j.IDest.DropTable(destTableName); err == nil {
 			break
 		}