## 20 EOAdaptorChannel class

An adaptor channel can open and close a connection to the adaptors database server. Along with fetch rows from the database and create, update, and delete rows in the database.

It is the main communication channel for gdl2, in creating the connection to the database, and executing any SQL statements which have been prepared through EOSQLExpression. Though it also has methods for building SQL expressions from entities, and possibly turning the results back into enterprise objects.

Because EOAdaptorChannel can create most SQL statements for you, you’ll rarely need to do that yourself, though it is available if needed.

Typical methods for an EOAdaptorChannel:

1. -openChannel
2. -closeChannel
3. -isOpen