Merge pull request #152 from github/validate-no-triggers

testing for trigger existence

build.sh

@@ -1,7 +1,7 @@
 #!/bin/bash
 #
 #
-RELEASE_VERSION="1.0.8"
+RELEASE_VERSION="1.0.9"
 
 buildpath=/tmp/gh-ost
 target=gh-ost

go/logic/inspect.go

@@ -69,6 +69,9 @@ func (this *Inspector) ValidateOriginalTable() (err error) {
 	if err := this.validateTableForeignKeys(); err != nil {
 		return err
 	}
+	if err := this.validateTableTriggers(); err != nil {
+		return err
+	}
 	if err := this.estimateTableRowsViaExplain(); err != nil {
 		return err
 	}
@@ -342,6 +345,34 @@ func (this *Inspector) validateTableForeignKeys() error {
 	return nil
 }
 
+// validateTableTriggers makes sure no triggers exist on the migrated table
+func (this *Inspector) validateTableTriggers() error {
+	query := `
+		SELECT COUNT(*) AS num_triggers
+			FROM INFORMATION_SCHEMA.TRIGGERS
+			WHERE
+				TRIGGER_SCHEMA=?
+				AND EVENT_OBJECT_TABLE=?
+	`
+	numTriggers := 0
+	err := sqlutils.QueryRowsMap(this.db, query, func(rowMap sqlutils.RowMap) error {
+		numTriggers = rowMap.GetInt("num_triggers")
+
+		return nil
+	},
+		this.migrationContext.DatabaseName,
+		this.migrationContext.OriginalTableName,
+	)
+	if err != nil {
+		return err
+	}
+	if numTriggers > 0 {
+		return log.Errorf("Found triggers on %s.%s. Triggers are not supported at this time. Bailing out", sql.EscapeName(this.migrationContext.DatabaseName), sql.EscapeName(this.migrationContext.OriginalTableName))
+	}
+	log.Debugf("Validated no triggers exist on table")
+	return nil
+}
+
 // estimateTableRowsViaExplain estimates number of rows on original table
 func (this *Inspector) estimateTableRowsViaExplain() error {
 	query := fmt.Sprintf(`explain select /* gh-ost */ * from %s.%s where 1=1`, sql.EscapeName(this.migrationContext.DatabaseName), sql.EscapeName(this.migrationContext.OriginalTableName))