mysql_field_type()

(PHP 4, PHP 5)

取得结果集中指定字段的类型

说明

mysql_field_type(resource $result,int $field_offset): string

mysql_field_type()和mysql_field_name()函数相似。参数完全相同，但返回的是字段类型而不是字段名。字段类型有“int”，“real”，“string”，“blob”以及其它，详见» MySQL 手册。

Example #1 mysql_field_type()例子

<?php
    mysql_connect("localhost", "mysql_username", "mysql_password");
    mysql_select_db("mysql");
    $result = mysql_query("SELECT * FROM func");
    $fields = mysql_num_fields($result);
    $rows   = mysql_num_rows($result);
    $table = mysql_field_table($result, 0);
    echo "Your '".$table."' table has ".$fields." fields and ".$rows." record(s)\n";
    echo "The table has the following fields:\n";
    for ($i=0; $i < $fields; $i++) {
        $type  = mysql_field_type($result, $i);
        $name  = mysql_field_name($result, $i);
        $len   = mysql_field_len($result, $i);
        $flags = mysql_field_flags($result, $i);
        echo $type." ".$name." ".$len." ".$flags."\n";
    }
    mysql_free_result($result);
    mysql_close();
?>

以上例子将产生如下输出：

Your 'func' table has 4 fields and 1 record(s)
The table has the following fields:
string name 64 not_null primary_key binary
int ret 1 not_null
string dl 128 not_null
string type 9 not_null enum

为向下兼容仍然可以使用mysql_fieldtype()，但反对这样做。

参数

$result: resource型的结果集。此结果集来自对mysql_query()的调用。
$field_offset: 数值型字段偏移量。$field_offset从0开始。如果$field_offset不存在，则会发出一个E_WARNING级别的错误

返回值

The returned field type will be one of"int","real","string","blob", and others as detailed in the » MySQL documentation.

范例

Example #2 mysql_field_type() example

<?php
mysql_connect("localhost", "mysql_username", "mysql_password");
mysql_select_db("mysql");
$result = mysql_query("SELECT * FROM func");
$fields = mysql_num_fields($result);
$rows   = mysql_num_rows($result);
$table  = mysql_field_table($result, 0);
echo "Your '" . $table . "' table has " . $fields . " fields and " . $rows . " record(s)\n";
echo "The table has the following fields:\n";
for ($i=0; $i < $fields; $i++) {
    $type  = mysql_field_type($result, $i);
    $name  = mysql_field_name($result, $i);
    $len   = mysql_field_len($result, $i);
    $flags = mysql_field_flags($result, $i);
    echo $type . " " . $name . " " . $len . " " . $flags . "\n";
}
mysql_free_result($result);
mysql_close();
?>

以上例程的输出类似于：

Your 'func' table has 4 fields and 1 record(s)
The table has the following fields:
string name 64 not_null primary_key binary
int ret 1 not_null
string dl 128 not_null
string type 9 not_null enum

注释

Note:
为了向下兼容，可以使用下列已废弃的别名：mysql_fieldtype()

参见

mysql_field_name()取得结果中指定字段的字段名
mysql_field_len()返回指定字段的长度

Hmm for the previous comment, note that SHOW FIELDS is an alias of SHOW COLUMNS. Very useful if you need to search the mysql-documentation. Here is the link anyway...
http://www.mysql.com/doc/en/SHOW_DATABASE_INFO.html

krang at krang dot org dot uk
Condensed version of what KRANG said.
To get info on the MYSQL field type, use this code
<?
$result = mysql_query("SHOW FIELDS FROM db_name");
$i = 1;
while ($row = mysql_fetch_array($result)) { //go through one field at a time
 echo "Field $i: ";
 print_r($row) //display all information about A field which can be accessed thru the "$row" array.
 $i++;
}
?>
Will display something like:
Field 1: Array ( [Field] => SN [Type] => mediumint(8) unsigned [Null] => [Key] => PRI [Default] => [Extra] => auto_increment ) , SN, mediumint(8) unsigned
Field 2: Array ( [Field] => ENTITY_ID [Type] => varchar(20) [Null] => [Key] => [Default] => [Extra] => ) , ENTITY_ID, varchar(20)

Additional to the note below:
If you're using the "SHOW FIELDS" syntax, be sure that you're adding the table name instead of the db name in the "FROM" parameter:
<?php
$result = mysql_query("SHOW FIELDS FROM table");
?>
Also possible:
<?php
$result = mysql_query("SHOW FIELDS FROM table.db");
?>
or this:
<?php
$result = mysql_query("DESCRIBE table");
?>
http://dev.mysql.com/doc/refman/5.1/en/describe.html

In MySQL 4.1.x, the four TEXT types (TINYTEXT, TEXT, MEDIUMTEXT, and LONGTEXT) return 'blob" as field types, not "string".

For version 4.3.4, types returned are:
STRING, VAR_STRING: string
TINY, SHORT, LONG, LONGLONG, INT24: int
FLOAT, DOUBLE, DECIMAL: real
TIMESTAMP: timestamp
YEAR: year
DATE: date
TIME: time
DATETIME: datetime
TINY_BLOB, MEDIUM_BLOB, LONG_BLOB, BLOB: blob
NULL: null
Any other: unknown

The field type returns what PHP classifies the data found in the field, not how it is stored in the database; use the following example to retrieve the MySQL information about the field....
$USERNAME = '';
$PASSWORD = '';
$DATABASE = '';
$TABLE_NAME = '';
mysql_connect('localhost', $USERNAME, $PASSWORD)
  or die ("Could not connect");
$result = mysql_query("SHOW FIELDS FROM $DATABASE.$TABLE_NAME");
$i = 0;
while ($row = mysql_fetch_array($result)) {
 echo $row['Field'] . ' ' . $row['Type'];
}