No, that's backwards. In SQL (at least in MySQL), you need to quote string values, not column names. A statement like this:

SELECT * FROM mytable WHERE customer = Smith;

tries to find rows where the value of the customer field equals the value of the Smith field. So it gives you an error like the one you got, complaining that there isn't a column named Smith. If you're looking for a customer whose name is Smith, you do:

SELECT * FROM mytable WHERE customer = 'Smith';

In Perl/DBI, you can do that a couple different ways. The second one below, using placeholders, is much safer, especially when searching on user-provided data (which is the case most of the time). It's also easier, because you let DBI do the quoting for you.

my $name = 'Smith';
my $st = $db->prepare( qq| SELECT * FROM mytable WHERE customer = '$na
+me'; | );
$st->execute or die $DBI::errstr;

# or with placeholders
my $name = 'Smith';
my $st = $db->prepare( q| SELECT * FROM mytable WHERE customer = ?; | 
+);
$st->execute($name) or die $DBI::errstr;

[download]

Aaron B.
Available for small or large Perl jobs; see my home node.

In reply to Re^3: Mysql Select Query by Perl by aaron_baugher
in thread Mysql Select Query by Perl by endymion

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


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.