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><H1
><A
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>PDOStatement-&#62;rowCount()</H1
><DIV
CLASS="refnamediv"
><A
NAME="AEN178065"
></A
><P
>    (no version information, might be only in CVS)</P
>PDOStatement-&#62;rowCount()&nbsp;--&nbsp;
   Returns the number of rows affected by the last SQL statement
  </DIV
><DIV
CLASS="refsect1"
><A
NAME="AEN178068"
></A
><H2
>说明</H2
>class <B
CLASS="classname"
>PDOStatement</B
> { <BR
></BR
>int <B
CLASS="methodname"
>rowCount</B
> ( void  )<BR
></BR
>}<P
>&#13;   <A
HREF="function.pdostatement-rowcount.html"
>PDOStatement-&#62;rowCount()</A
> returns the number of
   rows affected by the last DELETE, INSERT, or UPDATE statement
   executed by the corresponding <TT
CLASS="literal"
>PDOStatement</TT
> object. 
  </P
><P
>&#13;   If the last SQL statement executed by the associated 
   <TT
CLASS="literal"
>PDOStatement</TT
> was a SELECT statement, some databases
   may return the number of rows returned by that statement. However, this
   behaviour is not guaranteed for all databases and should not be relied
   on for portable applications.
  </P
></DIV
><DIV
CLASS="refsect1"
><A
NAME="AEN178082"
></A
><H2
>返回值</H2
><P
>&#13;   Returns the number of rows.
  </P
></DIV
><DIV
CLASS="refsect1"
><A
NAME="AEN178085"
></A
><H2
>范例</H2
><P
>&#13;   <TABLE
WIDTH="100%"
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CLASS="EXAMPLE"
><TR
><TD
><DIV
CLASS="example"
><A
NAME="AEN178088"
></A
><P
><B
>例 1. Return the number of deleted rows</B
></P
><P
>&#13;     <A
HREF="function.pdostatement-rowcount.html"
>PDOStatement-&#62;rowCount()</A
> returns the number of
     rows affected by a DELETE, INSERT, or UPDATE statement.
    </P
><TABLE
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CELLPADDING="5"
><TR
><TD
><code><font color="#000000">
<font color="#0000BB">&lt;?php<br /></font><font color="#FF8000">/* Delete all rows from the FRUIT table */<br /></font><font color="#0000BB">$del </font><font color="#007700">= </font><font color="#0000BB">$dbh</font><font color="#007700">-&gt;</font><font color="#0000BB">prepare</font><font color="#007700">(</font><font color="#DD0000">'DELETE FROM fruit'</font><font color="#007700">);<br /></font><font color="#0000BB">$del</font><font color="#007700">-&gt;</font><font color="#0000BB">execute</font><font color="#007700">();<br /><br /></font><font color="#FF8000">/* Return number of rows that were deleted */<br /></font><font color="#007700">print(</font><font color="#DD0000">"Return number of rows that were deleted:\n"</font><font color="#007700">);<br /></font><font color="#0000BB">$count </font><font color="#007700">= </font><font color="#0000BB">$del</font><font color="#007700">-&gt;</font><font color="#0000BB">rowCount</font><font color="#007700">();<br />print(</font><font color="#DD0000">"Deleted $count rows.</font><font color="#007700">\n</font><font color="#DD0000">"</font><font color="#007700">);<br /></font><font color="#0000BB">?&gt;</font>
</font>
</code></TD
></TR
></TABLE
><P
>上例将输出：</P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
CELLPADDING="5"
><TR
><TD
><PRE
CLASS="screen"
>Deleted 9 rows.</PRE
></TD
></TR
></TABLE
></DIV
></TD
></TR
></TABLE
>
   <TABLE
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CLASS="EXAMPLE"
><TR
><TD
><DIV
CLASS="example"
><A
NAME="AEN178095"
></A
><P
><B
>例 2. Counting rows returned by a SELECT statement</B
></P
><P
>&#13;     For most databases, <A
HREF="function.pdostatement-rowcount.html"
>PDOStatement-&#62;rowCount()</A
> does not
     return the number of rows affected by a SELECT statement. Instead, use
     <A
HREF="function.pdo-query.html"
>PDO-&#62;query()</A
> to issue a SELECT COUNT(*) statement
     with the same predicates as your intended SELECT statement, then use
     <A
HREF="function.pdostatement-fetchcolumn.html"
>PDOStatement-&#62;fetchColumn()</A
> to retrieve the number
     of rows that will be returned. Your application can then perform the
     correct action.
    </P
><TABLE
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><TD
><code><font color="#000000">
<font color="#0000BB">&lt;?php<br />$sql </font><font color="#007700">= </font><font color="#DD0000">"SELECT COUNT(*) FROM fruit WHERE calories &gt; 100"</font><font color="#007700">;<br />if (</font><font color="#0000BB">$res </font><font color="#007700">= </font><font color="#0000BB">$conn</font><font color="#007700">-&gt;</font><font color="#0000BB">query</font><font color="#007700">(</font><font color="#0000BB">$sql</font><font color="#007700">)) {<br /><br />&nbsp;&nbsp;&nbsp;&nbsp;</font><font color="#FF8000">/* Check the number of rows that match the SELECT statement */<br />&nbsp;&nbsp;</font><font color="#007700">if (</font><font color="#0000BB">$res</font><font color="#007700">-&gt;</font><font color="#0000BB">fetchColumn</font><font color="#007700">() &gt; </font><font color="#0000BB">0</font><font color="#007700">) {<br /><br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</font><font color="#FF8000">/* Issue the real SELECT statement and work with the results */<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</font><font color="#0000BB">$sql </font><font color="#007700">= </font><font color="#DD0000">"SELECT name FROM fruit WHERE calories &gt; 100"</font><font color="#007700">;<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;foreach (</font><font color="#0000BB">$conn</font><font color="#007700">-&gt;</font><font color="#0000BB">query</font><font color="#007700">(</font><font color="#0000BB">$sql</font><font color="#007700">) as </font><font color="#0000BB">$row</font><font color="#007700">) {<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;print </font><font color="#DD0000">"Name: " </font><font color="#007700">.&nbsp;&nbsp;</font><font color="#0000BB">$row</font><font color="#007700">[</font><font color="#DD0000">'NAME'</font><font color="#007700">] . </font><font color="#DD0000">"\n"</font><font color="#007700">;<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}<br />&nbsp;&nbsp;&nbsp;&nbsp;}<br />&nbsp;&nbsp;&nbsp;&nbsp;</font><font color="#FF8000">/* No rows matched -- do something else */<br />&nbsp;&nbsp;</font><font color="#007700">else {<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;print </font><font color="#DD0000">"No rows matched the query."</font><font color="#007700">;<br />&nbsp;&nbsp;&nbsp;&nbsp;}<br />}<br /><br /></font><font color="#0000BB">$res </font><font color="#007700">= </font><font color="#0000BB">null</font><font color="#007700">;<br /></font><font color="#0000BB">$conn </font><font color="#007700">= </font><font color="#0000BB">null</font><font color="#007700">;<br /></font><font color="#0000BB">?&gt;</font>
</font>
</code></TD
></TR
></TABLE
><P
>上例将输出：</P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
CELLPADDING="5"
><TR
><TD
><PRE
CLASS="screen"
>apple
banana
orange
pear</PRE
></TD
></TR
></TABLE
></DIV
></TD
></TR
></TABLE
>

  </P
></DIV
><DIV
CLASS="refsect1"
><A
NAME="AEN178104"
></A
><H2
>参见</H2
><P
>&#13;   <P
></P
><TABLE
BORDER="0"
><TBODY
><TR
><TD
><A
HREF="function.pdostatement-columncount.html"
>PDOStatement-&#62;columnCount()</A
></TD
></TR
><TR
><TD
><A
HREF="function.pdostatement-fetchcolumn.html"
>PDOStatement-&#62;fetchColumn()</A
></TD
></TR
><TR
><TD
><A
HREF="function.pdo-query.html"
>PDO-&#62;query()</A
></TD
></TR
></TBODY
></TABLE
><P
></P
>
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