String replace ' for mySQL insert

ruby-talk
1

Hello All,

I'm a newbie, just started programming Ruby about 1 month ago. Have lots
of experience with vb so the programming concepts are clear to me. I'm
building a script that is using the sample stream of the Twitter API and
insert it into MySQL for analysis. The problem is, that some of the
tweets have a ' in them. I want to replace them with '' so insert into
SQL is not a problem. I have written some piece of code trying to get
this to work, but the output replaces every letter with ''. This is the
code:

if line.include?"'"
   result=""
   teller=line.length-1
   for i in 1..teller do
      if line[i]="'"
         result=result + "''"
      else
         result=result + line[i]
      end
   end
   line=result
end

What am I doing wrong?

Thanks,
Roland

···

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2

Roland Klein overmeer wrote in post #977069:

I'm a newbie, just started programming Ruby about 1 month ago. Have lots
of experience with vb so the programming concepts are clear to me. I'm
building a script that is using the sample stream of the Twitter API and
insert it into MySQL for analysis. The problem is, that some of the
tweets have a ' in them. I want to replace them with '' so insert into
SQL is not a problem. I have written some piece of code trying to get
this to work, but the output replaces every letter with ''. This is the
code:

You're probably going about this the wrong way - your database layer
should provide a quoting mechanism for you. For example, if you're using
the low-level mysql-ruby then use Mysql.quote(str); if you're using
something like ActiveRecord then that handles quoting for you.

But to answer your direct question:

  line.gsub!("'","''")

would achieve what you're asking for.

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3

Thanks Brian,

for the eyeopener (and a quick fix)!

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4

in VB, '=' can means both assignment and equality, so the following does
what you expect:

if line[i]="'"

in ruby, you want '==' for equality (and '=' for assignment), so the above
line should be

···

if line[i]=="'"

On Mon, Jan 24, 2011 at 4:17 AM, Roland Klein overmeer < roland@kleinovermeer.nl> wrote:

Hello All,

I'm a newbie, just started programming Ruby about 1 month ago. Have lots
of experience with vb so the programming concepts are clear to me. I'm
building a script that is using the sample stream of the Twitter API and
insert it into MySQL for analysis. The problem is, that some of the
tweets have a ' in them. I want to replace them with '' so insert into
SQL is not a problem. I have written some piece of code trying to get
this to work, but the output replaces every letter with ''. This is the
code:

if line.include?"'"
  result=""
  teller=line.length-1
  for i in 1..teller do
     if line[i]="'"
        result=result + "''"
     else
        result=result + line[i]
     end
  end
  line=result
end

What am I doing wrong?

Thanks,
Roland

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Posted via http://www.ruby-forum.com/\.

5

thanks Ian,

Essential knowledge for the future!

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