1. A synchronization method for a database transformation, which is applied to a data adapter and a database transformer, the data adapter comprising a synchronization control unit, a storage unit and a statement parsing unit, the database transformer transforming tables from a source database into a target database, and the synchronization method comprising: using the synchronization control unit to determine a query mechanism; using the statement parsing unit to receive a database query statement and to parse a query table related to the database query statement; returning a transformation status of the query table to the synchronization control unit by the database transformer, wherein the transformation status comprises a blocking stage, a transforming stage or a completing stage; and using the synchronization control unit to perform the database query statement in the source database, the target database or both of them in accordance with the query mechanism and the transformation status; wherein the synchronization method further comprises: setting up the query mechanism as a blocking transformation mode; performing the database query statement in the source database if the transformation status is the blocking stage; using the storage unit to store the database query statement and then forming a to-be-synchronized database query statement if the transformation status is the transforming stage, and performing the to-be-synchronized database query statement in the source database when the transforming stage ends; performing the to-be-synchronized database query statement in the target database if the transformation status is the completing stage and the to-be-synchronized database query statement exists in the storage unit; performing the database query statement in the target database and the source database if the transformation status is the completing stage and the to-be-synchronized database query statement does not exist in the storage unit.