Merge pull request #81 from github/noop-show-create-table

a noop operation dumps SHOW CREATE TABLE

Author: Shlomi Noach

go/logic/inspect.go

@@ -516,6 +516,14 @@ func (this *Inspector) getSharedColumns(originalColumns, ghostColumns *sql.Colum
 	return sql.NewColumnList(sharedColumnNames), sql.NewColumnList(mappedSharedColumnNames)
 }
 
+// showCreateTable returns the `show create table` statement for given table
+func (this *Inspector) showCreateTable(tableName string) (createTableStatement string, err error) {
+	var dummy string
+	query := fmt.Sprintf(`show /* gh-ost */ create table %s.%s`, sql.EscapeName(this.migrationContext.DatabaseName), sql.EscapeName(tableName))
+	err = this.db.QueryRow(query).Scan(&dummy, &createTableStatement)
+	return createTableStatement, err
+}
+
 // readChangelogState reads changelog hints
 func (this *Inspector) readChangelogState() (map[string]string, error) {
 	query := fmt.Sprintf(`

go/logic/migrator.go

@@ -1173,6 +1173,16 @@ func (this *Migrator) executeWriteFuncs() error {
 // finalCleanup takes actions at very end of migration, dropping tables etc.
 func (this *Migrator) finalCleanup() error {
 	atomic.StoreInt64(&this.cleanupImminentFlag, 1)
+
+	if this.migrationContext.Noop {
+		if createTableStatement, err := this.inspector.showCreateTable(this.migrationContext.GetGhostTableName()); err == nil {
+			log.Infof("New table structure follows")
+			fmt.Println(createTableStatement)
+		} else {
+			log.Errore(err)
+		}
+	}
+
 	if err := this.retryOperation(this.applier.DropChangelogTable); err != nil {
 		return err
 	}