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MS SQL Maestro supports Service Broker communications designed around reliable, asynchronous message delivery. A contract is an agreement between two services about which messages each service sends to accomplish a particular task. Contract definitions persist in the database where the type is created. A contract defines which message types an application uses to accomplish a particular task.

You create an identical contract in each database that participates in a conversation. For example, if a human resources application wants to verify an employee ID, the service that requests the verification must know which types of messages the other service expects. The requesting service also must know which types of messages it can expect to receive so that it is prepared to process them.

The contract specifies which message types can be used to accomplish the desired work. The contract also specifies which participant in the conversation can use each message type. Some message types can be sent by either participant; other message types are restricted to be sent only by the initiator or only by the target. A contract must contain a message type sent by the initiator or a message type sent by either participant; otherwise, there is no way for the initiator to begin a conversation that uses the contract.

Create Contract Wizard guides you through the process of creating a new Service Broker contract. In order to run the wizard you should either

•	select the Object \| Create Database Object... main menu item;

•	select the Contracts icon in the Create Database Object dialog

•	select the Contracts list or any object from that list in the explorer tree;

•	select the Create Contract ... item from the popup menu

•	open the database in Database Editor and the Contracts tab there;

•	press the Insert key or select the Create New Contract ... item from the popup menu (alternatively, you may use the corresponding link of the Navigation Bar).

Contract Editor allows you to change contract options. In order to run the editor you should either

•	select the contract for editing in the explorer tree (type the first letters of the queue name for quick search);

•	select the Edit Contract ... item from the popup menu

•	open the database in Database Editor and the Contracts tab there;

•	select the contract to edit;

•	press the Enter key or select the Edit Contract item from the popup menu (alternatively, you may use the corresponding link of the Navigation Bar).

To drop a contract:

•	select the contract to drop in the explorer tree;

•	select the Drop Contract item from the popup menu

and confirm dropping in the dialog window.

MS SQL Maestro online Help

Contracts