mysql_fetch_field

(PHP 4, PHP 5)

mysql_fetch_field 从结果集中取得列信息并作为对象返回

说明

mysql_fetch_field ( resource $result [, int $field_offset ] ) : object

返回一个包含字段信息的对象。

mysql_fetch_field() 可以用来从某个查询结果中取得字段的信息。如果没有指定字段偏移量,则下一个尚未被 mysql_fetch_field() 取得的字段被提取。

对象的属性为:

  • name - 列名
  • table - 该列所在的表名
  • max_length - 该列最大长度
  • not_null - 1,如果该列不能为 NULL
  • primary_key - 1,如果该列是 primary key
  • unique_key - 1,如果该列是 unique key
  • multiple_key - 1,如果该列是 non-unique key
  • numeric - 1,如果该列是 numeric
  • blob - 1,如果该列是 BLOB
  • type - 该列的类型
  • unsigned - 1,如果该列是无符号数
  • zerofill - 1,如果该列是 zero-filled

Note: 此函数返回的字段名大小写敏感

Example #1 mysql_fetch_field()

<?php
mysql_connect
('localhost:3306'$user$password)
    or die(
"Could not connect: " mysql_error());
mysql_select_db("database");
$result mysql_query("select * from table")
    or die(
"Query failed: " mysql_error());
/* get column metadata */
$i 0;
while (
$i mysql_num_fields($result)) {
    echo 
"Information for column $i:<br />\n";
    
$meta mysql_fetch_field($result);
    if (!
$meta) {
        echo 
"No information available<br />\n";
    }
    echo 
"<pre>
blob:         
$meta->blob
max_length:   
$meta->max_length
multiple_key: 
$meta->multiple_key
name:         
$meta->name
not_null:     
$meta->not_null
numeric:      
$meta->numeric
primary_key:  
$meta->primary_key
table:        
$meta->table
type:         
$meta->type
unique_key:   
$meta->unique_key
unsigned:     
$meta->unsigned
zerofill:     
$meta->zerofill
</pre>"
;
    
$i++;
}
mysql_free_result($result);
?>

参见 mysql_field_seek()

参数

result

resource 型的结果集。此结果集来自对 mysql_query() 的调用。

field_offset

The numerical field offset. If the field offset is not specified, the next field that was not yet retrieved by this function is retrieved. The field_offset starts at 0.

返回值

Returns an object containing field information. The properties of the object are:

  • name - column name
  • table - name of the table the column belongs to
  • max_length - maximum length of the column
  • not_null - 1 if the column cannot be NULL
  • primary_key - 1 if the column is a primary key
  • unique_key - 1 if the column is a unique key
  • multiple_key - 1 if the column is a non-unique key
  • numeric - 1 if the column is numeric
  • blob - 1 if the column is a BLOB
  • type - the type of the column
  • unsigned - 1 if the column is unsigned
  • zerofill - 1 if the column is zero-filled

范例

Example #2 mysql_fetch_field() example

<?php
$conn 
mysql_connect('localhost''mysql_user''mysql_password');
if (!
$conn) {
    die(
'Could not connect: ' mysql_error());
}
mysql_select_db('database');
$result mysql_query('select * from table');
if (!
$result) {
    die(
'Query failed: ' mysql_error());
}
/* get column metadata */
$i 0;
while (
$i mysql_num_fields($result)) {
    echo 
"Information for column $i:<br />\n";
    
$meta mysql_fetch_field($result$i);
    if (!
$meta) {
        echo 
"No information available<br />\n";
    }
    echo 
"<pre>
blob:         
$meta->blob
max_length:   
$meta->max_length
multiple_key: 
$meta->multiple_key
name:         
$meta->name
not_null:     
$meta->not_null
numeric:      
$meta->numeric
primary_key:  
$meta->primary_key
table:        
$meta->table
type:         
$meta->type
unique_key:   
$meta->unique_key
unsigned:     
$meta->unsigned
zerofill:     
$meta->zerofill
</pre>"
;
    
$i++;
}
mysql_free_result($result);
?>

注释

Note: 此函数返回的字段名大小写敏感

参见

关注编程学问公众号