SQLite UPDATE with Shell script

I am really new to SQLite. I want to update BLOBs in the Column "data" in my database and i got it working: UPDATE genp SET data= X'MyHexData' WHERE rowid=510849 As i want to update multiple BLOBs from the Column data i decited to write a .sh script:

sqlite3 my.db 'UPDATE genp SET data= X'MyHexData' WHERE rowid=510849'

When i execute this script i get the error message:

SQL error: no such column: XMyHexData

Why does SQLite think that my hex data is supposed to be the column? Where is my mistake? It works if i run this in the Command Line Shell of SQLite.