sql - Oracle, restore from back up data with special conditions -

i'm trying restore database file 2 days ago, rows special conditions. build 2 databases , created database links between them. more detail in example:

currently:

city id   name   location    type 1         [sdo.geom]  1 2    b      [sdo.geom]  2  district id    name   atrr1      location     atrr2      type ... 1     aa     <null>     [sdo.geom]    1 2     bb      [sdo.geom]   <null>     2 3     cc      [sdo.geom]    1 4     dd     <null>     [sdo.geom]    1 

2 day agos:

city id   name   location    type 1         [sdo.geom]  1 2    b      [sdo.geom]  2 3    c      [sdo.geom]  1 4    d      [sdo.geom]  1  district id    name   atrr1      location     atrr2      type ... 1     aa           [sdo.geom]    1 3     cc     <null>     [sdo.geom]   <null>     1     

the question restore , type=1 in every tables, , if field 2 days ago null , have value remain. expect result is:

city id   name   location    type 1         [sdo.geom]  1 2    b      [sdo.geom]  2 3    c      [sdo.geom]  1 4    d      [sdo.geom]  1  district id    name   atrr1      location     atrr2      type ... 1     aa           [sdo.geom]    1 2     bb      [sdo.geom]   <null>     2 3     cc      [sdo.geom]    1     

as far can go, wrote script (using minus , stuff) return data like:

table     id    action city      3     "add" city      4     "add" district  1     "modify" district  3     "modify" (but nothing change) district  4     "remove" 

my plan remove first, re-add , modify (to avoid foreign key constraints).

the difficult part modifying, when use minus compare tables, don't know field changed, intend update fields. tables have different number of fields , special field sdo_geometry. need advice on how write procedure update whole rows database table name , primary key (id). thank you.