Php/docs/function.mysql-fetch-field
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()
<?phpmysql_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->blobmax_length: $meta->max_lengthmultiple_key: $meta->multiple_keyname: $meta->namenot_null: $meta->not_nullnumeric: $meta->numericprimary_key: $meta->primary_keytable: $meta->tabletype: $meta->typeunique_key: $meta->unique_keyunsigned: $meta->unsignedzerofill: $meta->zerofill</pre>"; $i++;}mysql_free_result($result);?>
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 at0
.
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->blobmax_length: $meta->max_lengthmultiple_key: $meta->multiple_keyname: $meta->namenot_null: $meta->not_nullnumeric: $meta->numericprimary_key: $meta->primary_keytable: $meta->tabletype: $meta->typeunique_key: $meta->unique_keyunsigned: $meta->unsignedzerofill: $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。