[HELP] Update a specific mysql colum with dbExec

[..:D&G:..]

Hello, I am trying to make a login system, and I want a function to update a specific username's data value.

dbExec( connection, "UPDATE `??` SET `??`=?", tableName, columnName, columnValue ) 

The problem with this is that I don't know how to make it so it updates the column only for a specific username, like "UPDATE 'accounts' WHERE 'username'="..user.." "

Thank you.

[Castillo]

dbExec( connection, "UPDATE `??` SET `??`=? WHERE username = ?", tableName, columnName, columnValue, username ) 

[..:D&G:..]

dbExec( connection, "UPDATE `??` SET `??`=? WHERE username = ?", tableName, columnName, columnValue, username ) 

Noticed that after I made the post, thanks