[Solved] which is the most easiest way to update BLOB value from developer tool?

Using SQLDeveloper

• Open the table which is having a BLOB field, i.e. USERS
• double-click on the BLOB field
• This will open the following pop-up

• 

• Click download in the Saved Data section to download the BLOB content to a File
  • You can click "Text" checkbox to view the data in the pop-up itself
• Update the downloaded file in the text editor and click "Load" in the Local Data section on the pop-up
  • Load will ask you to select the file
  • Select the updated file
  • Commit

Another easy way to do it is to use the oracle replace function on the blob field.

E.g. if you want to change "ValueA" to "ValueB" in the blob:

update MY_TABLE set BLOB_FIELD = replace(BLOB_FIELD, 'ValueA', 'ValueB') where [criteria];