note that
"SELECT <timestamp-field>, ..."
will return the field with type 7 (timestamp) but with content like "2010-07-14 14:35:08". the point being it is a string.
"SELECT <timestamp-field> + 0, ..."
returns a type 5 (double) but while a number, is not seconds since epoch, but a number in MySQL's "YYYYMMDDHHMMSS" format, in this example:
20100714143508
(PHP 5.2.12)
mysqli_result::fetch_field_direct
mysqli_fetch_field_direct
(PHP 5)
mysqli_result::fetch_field_direct -- mysqli_fetch_field_direct — Fetch meta-data for a single field
설명
객체 기반 형식
object mysqli_result::fetch_field_direct
( int $fieldnr
)
절차식 형식
object mysqli_fetch_field_direct
( mysqli_result $result
, int $fieldnr
)
Returns an object which contains field definition information from the specified result set.
인수
- result
-
순차 형식 전용: mysqli_query()나 mysqli_store_result()나 mysqli_use_result()가 반환한 결과셋 식별자.
- fieldnr
-
The field number. This value must be in the range from 0 to number of fields - 1.
반환값
Returns an object which contains field definition information or FALSE if no field information for specified fieldnr is available.
| Attribute | 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. |
| length | The width of the field, as specified in the table definition. |
| charsetnr | The character set number for the field. |
| 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) |
예제
Example #1 객체 기반 형식
<?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();
}
$query = "SELECT Name, SurfaceArea from Country ORDER BY Name LIMIT 5";
if ($result = $mysqli->query($query)) {
/* Get field information for column 'SurfaceArea' */
$finfo = $result->fetch_field_direct(1);
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", $finfo->type);
$result->close();
}
/* close connection */
$mysqli->close();
?>
Example #2 절차식 형식
<?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();
}
$query = "SELECT Name, SurfaceArea from Country ORDER BY Name LIMIT 5";
if ($result = mysqli_query($link, $query)) {
/* Get field information for column 'SurfaceArea' */
$finfo = mysqli_fetch_field_direct($result, 1);
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", $finfo->type);
mysqli_free_result($result);
}
/* close connection */
mysqli_close($link);
?>
위 예제들의 출력:
Name: SurfaceArea Table: Country max. Len: 10 Flags: 32769 Type: 4
참고
- mysqli_num_fields() - Get the number of fields in a result
- mysqli_fetch_field() - Returns the next field in the result set
- mysqli_fetch_fields() - Returns an array of objects representing the fields in a result set
bl at example dot com
09-Aug-2010 10:11
shoresofnowhere at gmail dot com
26-Aug-2009 03:50
Beware of the fact that the ->def property NEVER gets filled with the correct default field value, so it's totally USELESS.
This happens NOT for a bug in php (so don't go filling in a bug report), but happens BY DESIGN, since the MySQL C API call doesn't fill in this value, unless you call the mysql_list_fields() function, which Php doesn't.
See here for reference.
http://dev.mysql.com/doc/refman/5.0/en/c-api-datatypes.html
Also, be aware that if you're using a query which contains subqueries, the primary key/autoincrement flags do NOT get passed along, even if the field you're looking at is the primary autoincrement key of the master table:
SELECT * from (SELECT id from areas) AS subareas
and you'll find primary key and autoinc flags off on id field, even if id was the primary autoinc key of areas table.
This also is by design, i think, since it's supposed that if we're using a subquery then the primary key/autoinc stuff might have no sense at all, since in the result set we can compose fileds from many different tables.
Hoping this is useful, bye!
gcdreak at example dot com
18-Aug-2009 03:28
I wrote a simple class to get info about fields.
Try it!
<?php
class MysqlFieldsInfo implements Iterator
{
private $result;
private $position;
private $row;
function __construct($result){
$this->result = $result;
$this->position = 0;
$this->rewind(); // W $results wewnętrzny wskaźnik może być przesunięty więc powracamy do początku
}
public function current(){
return $this->row;
}
public function next(){
$this->position++;
$this->row = $this->result->fetch_field();
}
public function valid(){
return (boolean) $this->row;
}
public function key(){
return $this->position;
}
public function rewind(){
$this->position = 0;
$this->result->field_seek(0);
$this->next();
}
// This function show data in table
public function export(){
echo '<table id="db_table_info">';
echo '<tr>
<th>Name</th>
<th>Orgname</th>
<th>Table</th>
<th>Orgtable</th>
<th>Def</th>
<th>Max_length</th>
<th>Length</th>
<th>Charsetnr</th>
<th>Flags</th>
<th>Type</th>
<th>Decimals</th>
</tr>';
while($this->valid()){
echo '<tr>';
printf("\n\t<td>%s</td>\n", $this->current()->name);
printf("\t<td>%s</td>\n", $this->current()->orgname);
printf("\t<td>%s</td>\n", $this->current()->orgtable);
printf("\t<td>%s</td>\n", $this->current()->def);
printf("\t<td>%s</td>\n", $this->current()->max_length);
printf("\t<td>%s</td>\n", $this->current()->length);
printf("\t<td>%s</td>\n", $this->current()->charsetnr);
printf("\t<td>%s</td>\n", $this->current()->flags);
printf("\t<td>%s</td>\n", $this->current()->type);
printf("\t<td>%s</td>\n", $this->current()->decimals);
echo '</tr>';
$this->next();
}
echo '</table>';
}
}
?>
daniel at summit cove dot com
22-Feb-2009 03:36
Here's a bigger list of data types. I got this by creating every type I could and calling fetch_fields():
<?php
$mysql_data_type_hash = array(
1=>'tinyint',
2=>'smallint',
3=>'int',
4=>'float',
5=>'double',
7=>'timestamp',
8=>'bigint',
9=>'mediumint',
10=>'date',
11=>'time',
12=>'datetime',
13=>'year',
16=>'bit',
//252 is currently mapped to all text and blob types (MySQL 5.0.51a)
253=>'varchar',
254=>'char',
246=>'decimal'
);
?>
cjs at ashdowntech dot com
16-Sep-2008 09:52
According to
http://www.redferni.uklinux.net/mysql/MySQL-Protocol.html
Data type values are:
DECIMAL 0 ENUM 247
TINY 1 SET 248
SHORT 2 TINY_BLOB 249
LONG 3 MEDIUM_BLOB 250
FLOAT 4 LONG_BLOB 251
DOUBLE 5 BLOB 252
NULL 6 VAR_STRING 253
TIMESTAMP 7 STRING 254
LONGLONG 8 GEOMETRY 255
INT24 9
DATE 10
TIME 11
DATETIME 12
YEAR 13
NEWDATE 14
Note that this is not tested and does not contain
all the values noted by deluxmozart
cjs at ashdowntech dot com
12-Sep-2008 08:00
According to
dev.mysql.com/sources/doxygen/mysql-5.1/mysql__com_8h-source.html
the flag bits are:
NOT_NULL_FLAG 1 /* Field can't be NULL */
PRI_KEY_FLAG 2 /* Field is part of a primary key */
UNIQUE_KEY_FLAG 4 /* Field is part of a unique key */
MULTIPLE_KEY_FLAG 8 /* Field is part of a key */
BLOB_FLAG 16 /* Field is a blob */
UNSIGNED_FLAG 32 /* Field is unsigned */
ZEROFILL_FLAG 64 /* Field is zerofill */
BINARY_FLAG 128 /* Field is binary */
ENUM_FLAG 256 /* field is an enum */
AUTO_INCREMENT_FLAG 512 /* field is a autoincrement field */
TIMESTAMP_FLAG 1024 /* Field is a timestamp */
deluxmozart at yahoo dot de
24-Jul-2008 11:05
Here are some Numbers of Datatypes. I searched for it but i didn't find a list, where the datatypes of the numbers are listed.
so first I can give this:
3 - Int
10 - Date
246 - Decimal
252 - text
253 - VarChar
254 - Boolean
