How to use OEM to run a script against many databases

We had a requirement to create a particular user in all our 500+ databases. Instead of creating the user individually we thought of leveraging the power of OEM to do so and we succeeded in doing so by just a few clicks.

The steps followed are as followed:
1. Develop a script you want to get it executed.(sample provided below)
2. Go to Enterprise --> Job --> Library
3. In the "create library job" section select "SQL Script" and click "Go"
4. In the "General" section provide the "Name" of Job
5. Provide Target Type as "Database Instance"
6. Click "Parameters" and specify the SQL Script over there (sample provided below)
7. Click "Credentials" and specify the "Database" and "Host" credentials 
8. Click "Schedule" and specify how often you want to run the job, for me it was "One Time (Immediately)"
9. Finally "Save the job" to library

10. Once the job is saved to the Library, Select the job and click the "Submit" button
11. On the new page click "Add" to add the targets(in our case we have selected database instances) and then "Submit" the Job.



Sample SQL:
WHENEVER SQLERROR EXIT FAILURE;
DECLARE
cursor c1 is select DATABASE_ROLE from v$database;
db_role VARCHAR2(40);
BEGIN
open c1;
fetch c1 INTO db_role;
IF db_role='PRIMARY' THEN
execute immediate 'create user test identified by TesT_1_23';
execute immediate 'grant connect, resource to test';
dbms_output.put_line('created TEST user');
ELSE
dbms_output.put_line('STANDBY DATABSE');
END IF;
END;
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