Oracle APEX: getting invalid identifier error when using left outer join
When using left outer join with multiple tables, the order of table names listed in from clause matter. The following SQL statement gives error of invalid identifier on A.A_ID SELECT A.A_STUFF, B.B_STUFF FROM A_TABLE A, B_TABLE B LEFT OUTER JOIN C_TABLE C ON A.A_ID=C.C_ID WHERE C.FID = B.ID Change the order of the table, putting [...]
Good Statistical Report
Provide standard deviation instead of variance when giving a mean Round your numbers (no more than 3)in r, you can use summary(,digits =2) Think of logical plot ratio Line up digits
apex: when buttons don’t work
make sure you don’t have any other processings that don’t belong to any button. It’s possible your button also execute the unattached processing
Oracle 11g installation Error: username and password invalid
After installing Oracle 11g, you are prompted to login on https://localhost.com Some tutorial sites suggest “system/oracle” or “system/manager” But Nothing really worked for me. I just needed to access to sqlplus as sysdba and alter the user table from command window sqlplus / as sysdba alter user sys identified by syspass; alter user system identified [...]
Error Handling in Rails
Begin – Rescue – End begin #YOUR CODE SHOULD BE HERE rescue #IF YOUR CODE FAILS, THIS WILL BE EXECUTED end Example #!/usr/bin/ruby begin puts ‘I am before the raise.’ raise ‘An error has occurred.’ puts ‘I am after the raise.’ rescue puts ‘I am rescued.’ end puts ‘I am after the begin block.’ This [...]
Rails 3 and HTTP
To switch from HTTP to HTTPS or SSL: # config/application.rb module MyApp class Application < Rails::Application config.force_ssl = true end end
Rails Notes
Active Records update MyObject.update (params[:id], params[:myobj]) returns object whether passed or not. MyObject.valid? to check if the object is valid update_attribute vs. update_attributes Update_attribute updates one attribute as opposed to multiple attributes. When update_attribute is used, validation doesn’t get fired up for the model..