# maxdb_fetch_lengths

# maxdb_result::lengths

(PECL maxdb >= 1.0)

maxdb_fetch_lengths -- maxdb_result::lengths — Returns the lengths of the columns of the current row in the result set

### 说明

过程化风格

maxdb_fetch_lengths ( resource `$result` ) : array

面向对象风格

array $maxdb_result->lengths;

The maxdb_fetch_lengths() function returns an array containing the lengths of every column of the current row within the result set represented by the `result` parameter. If successful, a numerically indexed array representing the lengths of each column is returned 或者在失败时返回 `FALSE`.

### 返回值

An array of integers representing the size of each column (not including any terminating null characters). `FALSE` if an error occurred.

maxdb_fetch_lengths() is valid only for the current row of the result set. It returns `FALSE` if you call it before calling maxdb_fetch_row/array/resource or after retrieving all rows in the result.

### 范例

Example #1 面向对象风格

    <?php
    $maxdb = new maxdb("localhost", "MONA", "RED", "DEMODB");

    /* check connection */
    if (maxdb_connect_errno()) {
       printf("Connect failed: %s\n", maxdb_connect_error());
       exit();
    }

    $query = "SELECT * from hotel.customer WHERE cno = 3000";

    if ($result = $maxdb->query($query)) {

       $row = $result->fetch_row();

       /* display column lengths */
       foreach ($result->lengths as $i => $val) {
           printf("Field %2d has Length %2d\n", $i+1, $val);
       }
       $result->close();
    }

    /* close connection */
    $maxdb->close();
    ?>

Example #2 过程化风格

    <?php
    $link = maxdb_connect("localhost", "MONA", "RED", "DEMODB");

    /* check connection */
    if (maxdb_connect_errno()) {
       printf("Connect failed: %s\n", maxdb_connect_error());
       exit();
    }

    $query = "SELECT * from hotel.customer WHERE cno = 3000";

    if ($result = maxdb_query($link, $query)) {

       $row = maxdb_fetch_row($result);

       /* display column lengths */
       foreach (maxdb_fetch_lengths($result) as $i => $val) {
           printf("Field %2d has Length %2d\n", $i+1, $val);
       }
       maxdb_free_result($result);
    }

    /* close connection */
    maxdb_close($link);
    ?>

以上例程的输出类似于：

    Field  1 has Length  4
    Field  2 has Length  3
    Field  3 has Length  5
    Field  4 has Length  6
    Field  5 has Length  5
    Field  6 has Length 21