         return chunks.joined(separator: " ")
     }
     
-    fileprivate func indexDefinition(in table: String) -> IndexDefinition? {
+    fileprivate func indexDefinition(in table: String, ifNotExists: Bool) -> IndexDefinition? {
         switch index {
         case .none: return nil
         case .unique: return nil

                let statement = chunks.joined(separator: " ")
                statements.append(statement)
                
                if let indexDefinition = column.indexDefinition(in: name) {
                    try statements.append(indexDefinition.sql(db))
                }
            case let .rename(oldName, newName):

                table: table,
                columns: [name],
                unique: false,
                ifNotExists: ifNotExists,
                condition: nil)
        }
    }
