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このドキュメントでは、 php中国語ネットマニュアル リリース
(PHP 5)
mysqli_result::$lengths -- mysqli_fetch_lengths — Returns the lengths of the columns of the current row in the result set
面向对象风格
过程化风格
$result
)The mysqli_fetch_lengths() function returns an array containing the lengths of every column of the current row within the result set.
result
仅以过程化样式:由 mysqli_query() , mysqli_store_result() 或 mysqli_use_result() 返回的结果集标识。
An array of integers representing the size of each column (not including
any terminating null characters). FALSE
if an error occurred.
mysqli_fetch_lengths() is valid only for the current
row of the result set. It returns FALSE
if you call it before calling
mysqli_fetch_row/array/object or after retrieving all rows in the result.
Example #1 面向对象风格
<?php
$mysqli = new mysqli ( "localhost" , "my_user" , "my_password" , "world" );
if ( mysqli_connect_errno ()) {
printf ( "Connect failed: %s\n" , mysqli_connect_error ());
exit();
}
$query = "SELECT * from Country ORDER BY Code LIMIT 1" ;
if ( $result = $mysqli -> query ( $query )) {
$row = $result -> fetch_row ();
foreach ( $result -> lengths as $i => $val ) {
printf ( "Field %2d has Length %2d\n" , $i + 1 , $val );
}
$result -> close ();
}
$mysqli -> close ();
?>
Example #2 过程化风格
<?php
$link = mysqli_connect ( "localhost" , "my_user" , "my_password" , "world" );
if ( mysqli_connect_errno ()) {
printf ( "Connect failed: %s\n" , mysqli_connect_error ());
exit();
}
$query = "SELECT * from Country ORDER BY Code LIMIT 1" ;
if ( $result = mysqli_query ( $link , $query )) {
$row = mysqli_fetch_row ( $result );
foreach ( mysqli_fetch_lengths ( $result ) as $i => $val ) {
printf ( "Field %2d has Length %2d\n" , $i + 1 , $val );
}
mysqli_free_result ( $result );
}
mysqli_close ( $link );
?>
以上例程会输出:
Field 1 has Length 3 Field 2 has Length 5 Field 3 has Length 13 Field 4 has Length 9 Field 5 has Length 6 Field 6 has Length 1 Field 7 has Length 6 Field 8 has Length 4 Field 9 has Length 6 Field 10 has Length 6 Field 11 has Length 5 Field 12 has Length 44 Field 13 has Length 7 Field 14 has Length 3 Field 15 has Length 2