PHP 手册
后退		前进

mysqli_fetch_field

(PHP 5)

mysqli_fetch_field

(no version information, might be only in CVS)

result->fetch_field -- Returns the next field in the result set

Description

Procedural style:

object mysqli_fetch_field ( mysqli_result result )

Object oriented style (method):

class mysqli_result {

object fetch_field ( void )

}

The mysqli_fetch_field() returns the definition of one column of a result set as an object. Call this function repeatedly to retrieve information about all columns in the result set. mysqli_fetch_field() returns FALSE when no more fields are left.

返回值

Returns an object which contains field definition information or FALSE if no field information is available.

表格 1. Object properties

Property	Description
name	The name of the column
orgname	Original column name if an alias was specified
table	The name of the table this field belongs to (if not calculated)
orgtable	Original table name if an alias was specified
def	The default value for this field, represented as a string
max_length	The maximum width of the field for the result set.
flags	An integer representing the bit-flags for the field.
type	The data type used for this field
decimals	The number of decimals used (for integer fields)

参见

mysqli_num_fields(), mysqli_fetch_field_direct(), mysqli_fetch_fields() 和 mysqli_field_seek().

范例

例子 1. Object oriented style


<?php
$mysqli = new mysqli("localhost", "my_user", "my_password", "world");

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

$query = "SELECT Name, SurfaceArea from Country ORDER BY Code LIMIT 5";

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

    /* Get field information for all columns */
    while ($finfo = $result->fetch_field()) {
 
        printf("Name:     %s\n", $finfo->name);
        printf("Table:    %s\n", $finfo->table);
        printf("max. Len: %d\n", $finfo->max_length);
        printf("Flags:    %d\n", $finfo->flags);
        printf("Type:     %d\n\n", $finfo->type);
    }    
    $result->close();
}

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

例子 2. Procedural style


<?php
$link = mysqli_connect("localhost", "my_user", "my_password", "world");

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

$query = "SELECT Name, SurfaceArea from Country ORDER BY Code LIMIT 5";

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

    /* Get field information for all fields */
    while ($finfo = mysqli_fetch_field($result)) {
 
        printf("Name:     %s\n", $finfo->name);
        printf("Table:    %s\n", $finfo->table);
        printf("max. Len: %d\n", $finfo->max_length);
        printf("Flags:    %d\n", $finfo->flags);
        printf("Type:     %d\n\n", $finfo->type);
    }
    mysqli_free_result($result);
}

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

上例将输出：

Name:     Name
Table:    Country
max. Len: 11
Flags:    1
Type:     254

Name:     SurfaceArea
Table:    Country
max. Len: 10
Flags:    32769
Type:     4

add a note User Contributed Notes

dedlfix
19-Jul-2006 01:26


There are MYSQLI_TYPE_* constants for the type property (listed in http://php.net/manual/en/ref.mysqli.php).



e.g.

<?php

if ($finfo->type == MYSQLI_TYPE_VAR_STRING)

  // a VARCHAR

jakerosoft at hotmail dot com
17-Aug-2005 12:15


<?


$fieldinfo = $result->fetch_field();


if ($fieldinfo & MYSQLI_NOT_NULL_FLAG)  {


  print "not null flag is set";


} else {


  print "not null flag is NOT set";


}


?>

Marc-Andr
08-Jul-2005 06:56


The "type" property will return a numerical representation of a field type instead of a "meaningful" string.



Here is an array that may help you:



<?php 

$mysqli_type = array();

$mysqli_type[0] = "decimal";

$mysqli_type[1] = "tinyint";

$mysqli_type[2] = "smallint";

$mysqli_type[3] = "int";

$mysqli_type[4] = "float";

$mysqli_type[5] = "double";

$mysqli_type[7] = "timestamp";

$mysqli_type[8] = "bigint";

$mysqli_type[9] = "mediumint";

$mysqli_type[10] = "date";

$mysqli_type[11] = "time";

$mysqli_type[12] = "datetime";

$mysqli_type[13] = "year";

$mysqli_type[252] = "blob"; // text, blob, tinyblob,mediumblob, etc...

$mysqli_type[253] = "string"; // varchar and char

$mysqli_type[254] = "enum";

?>

add a note

后退	起点	前进
mysqli_fetch_field_direct	上一级	mysqli_fetch_fields