Beefy Boxes and Bandwidth Generously Provided by pair Networks
go ahead... be a heretic
 
PerlMonks  

comment on

( #3333=superdoc: print w/replies, xml ) Need Help??
I hope this info can help you with your 2nd
question.

Off the top of my head there are aleast 3 ways
to check the table before you insert a new record.

way one) would be to define a unique constraint
on this table in the DBMS. This will prevent any
insertion of a record that is a duplicate.

way two) would be to define a before insert trigger
and have this trigger check for a duplicate.

way three) execute the query select count(*) into n from ...
and if n > 0 then the record exist.

--
Its like a dog that can sing and dance.
It's remarkable because it can do it.
Not that it can do it well.

In reply to Re: Handling Null or Undef values in DBI (and things of those nature)... by rbc
in thread Handling Null or Undef values in DBI (and things of those nature)... by data67

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":



  • Are you posting in the right place? Check out Where do I post X? to know for sure.
  • Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
    <code> <a> <b> <big> <blockquote> <br /> <dd> <dl> <dt> <em> <font> <h1> <h2> <h3> <h4> <h5> <h6> <hr /> <i> <li> <nbsp> <ol> <p> <small> <strike> <strong> <sub> <sup> <table> <td> <th> <tr> <tt> <u> <ul>
  • Snippets of code should be wrapped in <code> tags not <pre> tags. In fact, <pre> tags should generally be avoided. If they must be used, extreme care should be taken to ensure that their contents do not have long lines (<70 chars), in order to prevent horizontal scrolling (and possible janitor intervention).
  • Want more info? How to link or or How to display code and escape characters are good places to start.
Log In?
Username:
Password:

What's my password?
Create A New User
Domain Nodelet?
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others romping around the Monastery: (3)
As of 2022-08-14 11:45 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    No recent polls found

    Notices?