On 12/21/05, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote:
>
>
> Nathan Gross <[EMAIL PROTECTED]> wrote on 12/21/2005 11:20:50 AM:
>
>
> > On 12/20/05, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote:
> > > Nathan Gross <[EMAIL PROTECTED]> wrote on 12/20/2005 05:34:58 PM:
> > >
> > > > Hi;
> > > > [Mysql 4x] In a table where I get data from another program, I have
> > > > many records (about 1000) that have illegal chars in a [unique]
> > > > indexed varchar field. I would like to clean the illegal characters
> > > > out and leave the rest of the data intact.
> > > > 1. Is there a utility to do this?
> > > > 1b) Or an UPDATE command?
> > > >
> > > > Problem is that I do not even know which characters are illegal.
> > > > For the future, I can have my Java program check before the inserts.
> > > >
> > > > 2. What are the illegal characters?
> > > >
> > > > Thank you.
> > > > -nat
> > > >
> > >
> > > If you don't know what is illegal, how do you know you have illegal
> > > characters? Are you getting some kind of error message or warning? You
> have
> > > to give us the same information you have in order for us to make an
> informed
> > > decision.
> > I get two lists from different sources which I merge into the database
> > via a Java program. Since these two lists themselves sometimes get
> > their data from the same source, my program first does a SELECT on the
> > varchar field (unique index) [to ensure that this data is not yet in
> > the db] before inserting the data. (Actually I am using j2ee
> > ejbFinds.)
> > Occasionaly, say 5% of the time, I get a duplicate (create) exception
> > from the db, even though the db just told my program that the data was
> > not there!
> > With my debugger I verified that for these fields, if you try to
> > find/select this data, mysql will return a null resultset, but yet if
> > you try to enter this data it will throw the create exception.
> > Now these [defective] fields always have (1 or more) suspicious
> > characters like {,[,',", or commas colons, what not. I do not know
> > which of these is/are the culprits.
> > So, my little problem is twofold.
> > 1) How to trap this data in the first place in my Java program.
> > Obviously I need to know what to look for!
> > 2) I do not want to leave my database in this state, so I want to clean
> it.
> > 2b)I don't mind adding a boolean field to the table to be used as a
> > flag for all records that have suspect data, before deciding exactly
> > how to clean it. Although I think I can just replace these characters
> > with a space, in [almost] all cases.
> >
> > One more important point. This field, although unique, is NOT the pk.
> > I can use the PK to correctly select and display the contents of all
> > fields in the record.
> >
> > Thank you much.
> > -nat
>
> I believe that what you are describing is the inability to properly escape a
> query string in order to make an appropriate match. Please look at this page
> for how to escape your incoming data properly so that you can probably avoid
> the problems you describe.
>
> http://dev.mysql.com/doc/refman/4.1/en/string-syntax.html
Does this mean that any character NOT on that page is legal? Like a
brace {} or brackets[]?
> Nearly every mysql client library has some kind of function to perform this
> escaping for you. Please refer to the manual of the client library you are
> using to see if your client has it or if it escapes content as part of the
> execution of certain methods or calls.
I use Java. I don't know where to look for such a function.
Thank you.
-nat
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