I have a field in SQL server that has a bunch of different sized strings in it. I need to cut down or truncate all of these strings so that they are 16 characters long, but I do not want to do this using a `select` statement. 

I know that I can use:

```
insert into some_table (column1, column2, ...)
    select left(column1, 16), column2, ...
    from some_other_table

```

then insert the newly shortened strings back into the 1st table, but I do not want to do this, it is too round about. 

Is there a command I can use to just cut the strings down to 16 characters in the table I am already in? I tried to mess around with the `TRIM` command, but that would only remove the spaces off of the end or beginning