Return Value
For UPDATE, INSERT, and DELETE statements, the return value is the number of rows affected by the command. For all other types of statements, the return value is -1.
You can use ExecuteNonQuery method to perform catalog operations (for example, querying the structure of a database or creating database objects such as tables); or to change the data in a database, without using a DataSet, by executing UPDATE, INSERT, or DELETE statements.
Although Devart.Data.Oracle.OracleCommand.ExecuteNonQuery does not return any rows, any output parameters or return values mapped to parameters are populated with data.