Php/docs/mysqli-result.fetch-field-direct
mysqli_result::fetch_field_direct
mysqli_fetch_field_direct
(PHP 5, PHP 7)
mysqli_result::fetch_field_direct -- mysqli_fetch_field_direct — Fetch meta-data for a single field
说明
面向对象风格
public mysqli_result::fetch_field_direct
( int $fieldnr
) : object
过程化风格
mysqli_fetch_field_direct
( mysqli_result $result
, int $fieldnr
) : object
Returns an object which contains field definition information from the specified result set.
参数
result
- 仅以过程化样式:由 mysqli_query(),mysqli_store_result() 或 mysqli_use_result()返回的结果集标识。
fieldnr
- The field number. This value must be in the range from
0
tonumber of fields - 1
.
返回值
Returns an object which contains field definition information or false
if no field information for specified fieldnr
is
available.
Attribute | Description |
---|---|
name | The name of the column |
orgname | Original column name if an alias was specified |
table | The name of the table this field belongs to (if not calculated) |
orgtable | Original table name if an alias was specified |
def | The default value for this field, represented as a string |
max_length | The maximum width of the field for the result set. |
length | The width of the field, as specified in the table definition. |
charsetnr | The character set number for the field. |
flags | An integer representing the bit-flags for the field. |
type | The data type used for this field |
decimals | The number of decimals used (for numeric fields) |
范例
Example #1 面向对象风格
<?php$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 过程化风格
<?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);?>
以上例程会输出:
Name: SurfaceArea Table: Country max. Len: 10 Flags: 32769 Type: 4
参见
- 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