Searching for a word in a column made of sentences

I'm using SQLite3 with python in JetBrains PyCharm Community Edition 4.0.4.

I have a table that looks like this. ID is integer, name and content are text.

ID Name Content
1  Matt oirefasd aifsfnib if ib @John sefuhrg wefirwgf
2  John sdfwre frwgfwg wegfhtr @Patsfrwg
3  Pat  asjgre wurgjnsow wouregjeo @Johnsfbwufaeovnwo
4  John sfgoe eriogner weogfib

So here is my question, Assume a user John, is logged in. How do I write the sqlite query such that I receive the rows that contain messages starting with @ symbol followed by the user that is logged in (John) in the Content column.

I should receive the answer as a tuple.(ID, Name, Content)

So the solution should be:

ID Name Content
1  Matt oirefasd aifsfnib if ib @John sefuhrg wefirwgf
3  Pat  asjgre wurgjnsow wouregjeo @Johnsfbwufaeovnwo 

This is my current sql query. currentuser stores the name of the current logged in user in this case John.

str = '%'+ currentuser + '%'
c = db.cursor()
sql = "SELECT id, Name, content FROM myusers WHERE myusers.content LIKE ? LiMIT ?"
c.execute(sql,(str,limit))
return [x[0] for x in c]

I keep getting an error which says "'int' object is not subscriptable"