CreateDatabaseDesc createDatabaseDesc = work.getCreateDatabaseDesc();
if (null != createDatabaseDesc) {
return createDatabase(db, createDatabaseDesc);
}
DropDatabaseDesc dropDatabaseDesc = work.getDropDatabaseDesc();
if (dropDatabaseDesc != null) {
return dropDatabase(db, dropDatabaseDesc);
}
SwitchDatabaseDesc switchDatabaseDesc = work.getSwitchDatabaseDesc();