Can Oracle SQL developer export data as a set of Update commands

exportoracle

Oracle SQL developer gives us the option of exporting data. But it only gives us the option to export as a set of Insert statements.

I have two databases with a mirrored table. One of them has some column data missing from it. I tried truncating the data from that table but it has foreign keys associated and SQL doesn't let me drop it.

Is there a way to export the data from the larger/fuller table in the form of "Update Table…" commands? I tried googling first, failed. I bet there's a solution for this out there.

If nothing else, I am thinking of making a small python script that modifies the Insert command set into an Update command set after export.

Best Answer

Not using a built in command, but...

If an UPDATE really can satisfy your requirements as your title implies, then no inserts should be necessary and the primary key must be in sync between the databases.

Your requirements don't allow remote updates, but if you can remotely query the database, then you can join the local table to the remote table to create the statements that will need to be run the remote system. Here is a demonstration:

drop table t1;
drop table t2;
create table t1 as (select level c1, level c2 from dual connect by level <=7);
create table t2 as (select * from t1);
update t2 set c2 = null where c1 in (3,6);
select * from t1;
select * from t2;

select 'UPDATE t2 SET c2 = ' || t1.c2 || ' WHERE c1=' || t1.c1 || ';' sql from t1 
join t2 on t1.c1 = t2.c1
where t1.c2 <> t2.c2 OR t2.c2 is null;

If you cannot query the remote database, you can update every row like this:

drop table t1;
create table t1 as (select level c1, level c2 from dual connect by level <=7);

select 'UPDATE t2 SET c2 = ' || t1.c2 || ' WHERE c1=' || t1.c1 || ';' sql from t1;

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Your simple solution is to import into a separate table and then use another query to copy the data back, converting to proper format.

Update oracle sql database from CSV

I would suggest you to make use of External Tables. You can create an external table on your CSV file using ORACLE_LOADER driver and then update your existing table with data in your external table using DML (MERGE for example).

Consult Oracle Utilities Guide for detailed info.

What follows is my sample of how you can update tables from flat files.

First you create the directory where your flat file will be located:

SQL> create directory ext_tab_dir as '/home/oracle/ora_load';
Directory created.

SQL> grant read, write on directory ext_tab_dir to spongebob;
Grant succeeded.

Then you create your external table:

SQL> CREATE TABLE emp_load (empid          number(3), 
                            first_name     CHAR(15), 
                            last_name      CHAR(20), 
                            year_of_birth  CHAR(4))
       ORGANIZATION EXTERNAL (
         TYPE ORACLE_LOADER DEFAULT DIRECTORY ext_tab_dir
         ACCESS PARAMETERS (RECORDS FIXED 21 FIELDS (
           empid          char(1),
           first_name     CHAR(7),
           last_name      CHAR(8),
           year_of_birth  CHAR(4)))
         LOCATION ('info.dat')
       );

We'll assume that you already have the table that you want to update with data from the flat file:

SQL> CREATE TABLE emp (empid         number(3), 
                      first_name     CHAR(15), 
                      last_name      CHAR(20), 
                      year_of_birth  CHAR(4));
SQL> insert into emp values(1, 'SpongeBob', 'SquarePants', '1997');
SQL> insert into emp values(2, 'Patrick',   'Star',        '1997');
SQL> insert into emp values(3, 'Squidward', 'Tentacles',   '1997');

(Here, I just loaded it with sample data.)

Now that's what your info.dat contains, for example:

[oracle@oca ~]$ cat ora_load/info.dat
1Alvin  Tolliver1976
2KennethBaer    1963
3Mary   Dube    1973
4NandiniShastri 1985

At this point you will just update your existing table with above data from the external table:

SQL> merge into emp e1
       using emp_load e2
       on (e1.empid = e2.empid)
       when matched then update set e1.first_name    = e2.first_name,
                                    e1.last_name     = e2.last_name
       when not matched then insert
         values (e2.empid, e2.first_name, e2.last_name, e2.year_of_birth);

Here's what you'll get as a result:

SQL> select * from emp;
     EMPID FIRST_NAME      LAST_NAME            YEAR
---------- --------------- -------------------- ----
         1 Alvin           Tolliver             1997
         2 Kenneth         Baer                 1997
         3 Mary            Dube                 1997
         4 Nandini         Shastri              1985

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