It is possible to synchronize a model in MySQL Workbench with a live database. By default, the synchronization process will change the live database to be the same as the model, but this is configurable during the synchronization process.

MySQL Workbench enables control over the direction of synchronization, and which objects to synchronize, in a completely flexible way. You can choose to synchronize only certain tables, enable synchronization to the live database only, enable synchronization from the live database to the model only, or a combination of directions. In effect you have complete control as to whether the synchronization is unidirectional or bidirectional, and which objects exactly are subject to synchronization. This is all controlled in the Select Changes to Apply page of the synchronization wizard.

Figure 7.38. Model and Database Differences

In the preceding example, the live database consists of table1, table2 and table3. In MySQL Workbench an additional table, table4, has been created, along with a relationship between it and table3. Further, table5 exists in the live database, but not in the model. The actions that are configured to occur would result in table3 being altered (to include the relationship with table4), table4 being created and table5 being dropped, in the live database. It is possible to reconfigure this, though.

The next example shows how the direction of synchronization can be changed.

Figure 7.39. Controlling Synchronization Direction

In this case, the synchronization direction has been changed so that rather than the default action of table5 being dropped from the live database, it will be incorporated into the MySQL Workbench model.

For convenience, the wizard provides three additional buttons to enable synchronization directions to be applied to a group of selected changes. The Update Model button causes the selected changes to be applied only to the model itself. In the following example, table7 would be added to the model.

Figure 7.40. Update Model Button

The Ignore button causes the selected changes to be ignored. No synchronization will take place for those changes. In the following example, no changes would take place.

Figure 7.41. Ignore Button

The Update Source button causes the selected changes to be applied only to the live database. In the following example, table6 would be added to the live database and table7 would be dropped from the live database.

Figure 7.42. Update Source Button

It is also possible to control individual changes by clicking the arrows. Clicking an arrow causes it to change between the three available synchronization directions: from model to source, from source to model, or bidirectionally. In the following example, table6 will be created in the live database, and table7 will be created in the model.

Figure 7.43. Click Arrows to Change Direction of Synchronization