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mysqli_result::fetch_fields
mysqli_fetch_fields
Returns an array of objects representing the fields in a result set
Description
Object-oriented style
public array mysqli_result::fetch_fields()
array mysqli_fetch_fields(mysqli_result $result)
Parameters
-
result
-
Procedural style only: A mysqli_result
object returned by mysqli_query, mysqli_store_result,
mysqli_use_result or mysqli_stmt_get_result.
Return Values
Returns an array of objects containing field definition information.
Object properties
| Property |
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 |
Unused. Always an empty string |
| db |
The name of the database |
| catalog |
Unused. Always "def" |
| max_length |
The maximum width of the field for the result set. As of PHP 8.1, this value is always 0. |
| length |
The width of the field in bytes. For string columns,
the length value varies on the connection character set. For example,
if the character set is latin1, a single-byte character set,
the length value for a SELECT 'abc' query is 3.
If the character set is utf8mb4, a multibyte character
set in which characters take up to 4 bytes, the length value is 12.
|
| 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 for numeric fields, and the fractional seconds precision for temporal fields. |
Examples
Example #1 Object-oriented style
<?php
$mysqli = new mysqli("127.0.0.1", "root", "foofoo", "sakila");
/* check connection */
if ($mysqli->connect_errno) {
printf("Connect failed: %s\n", $mysqli->connect_error);
exit();
}
foreach (array('latin1', 'utf8') as $charset) {
// Set character set, to show its impact on some values (e.g., length in bytes)
$mysqli->set_charset($charset);
$query = "SELECT actor_id, last_name from actor ORDER BY actor_id";
echo "======================\n";
echo "Character Set: $charset\n";
echo "======================\n";
if ($result = $mysqli->query($query)) {
/* Get field information for all columns */
$finfo = $result->fetch_fields();
foreach ($finfo as $val) {
printf("Name: %s\n", $val->name);
printf("Table: %s\n", $val->table);
printf("Max. Len: %d\n", $val->max_length);
printf("Length: %d\n", $val->length);
printf("charsetnr: %d\n", $val->charsetnr);
printf("Flags: %d\n", $val->flags);
printf("Type: %d\n\n", $val->type);
}
$result->free();
}
}
$mysqli->close();
?>
Example #2 Procedural style
<?php
$link = mysqli_connect("127.0.0.1", "my_user", "my_password", "sakila");
/* check connection */
if (mysqli_connect_errno()) {
printf("Connect failed: %s\n", mysqli_connect_error());
exit();
}
foreach (array('latin1', 'utf8') as $charset) {
// Set character set, to show its impact on some values (e.g., length in bytes)
mysqli_set_charset($link, $charset);
$query = "SELECT actor_id, last_name from actor ORDER BY actor_id";
echo "======================\n";
echo "Character Set: $charset\n";
echo "======================\n";
if ($result = mysqli_query($link, $query)) {
/* Get field information for all columns */
$finfo = mysqli_fetch_fields($result);
foreach ($finfo as $val) {
printf("Name: %s\n", $val->name);
printf("Table: %s\n", $val->table);
printf("Max. Len: %d\n", $val->max_length);
printf("Length: %d\n", $val->length);
printf("charsetnr: %d\n", $val->charsetnr);
printf("Flags: %d\n", $val->flags);
printf("Type: %d\n\n", $val->type);
}
mysqli_free_result($result);
}
}
mysqli_close($link);
?>
The above examples will output:
======================
Character Set: latin1
======================
Name: actor_id
Table: actor
Max. Len: 3
Length: 5
charsetnr: 63
Flags: 49699
Type: 2
Name: last_name
Table: actor
Max. Len: 12
Length: 45
charsetnr: 8
Flags: 20489
Type: 253
======================
Character Set: utf8
======================
Name: actor_id
Table: actor
Max. Len: 3
Length: 5
charsetnr: 63
Flags: 49699
Type: 2
Name: last_name
Table: actor
Max. Len: 12
Length: 135
charsetnr: 33
Flags: 20489
See Also
- mysqli_num_fields
- mysqli_fetch_field_direct
- mysqli_fetch_field
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