Php/docs/mysqli-result.field-count
mysqli_result::$field_count
mysqli_num_fields
(PHP 5, PHP 7)
mysqli_result::$field_count -- mysqli_num_fields — Get the number of fields in a result
说明
面向对象风格
int $mysqli_result->field_count;
过程化风格
mysqli_num_fields
( mysqli_result $result
) : int
Returns the number of fields from specified result set.
返回值
The number of fields from a result set.
范例
Example #1 面向对象风格
<?php$mysqli = new mysqli("localhost", "my_user", "my_password", "world");/* check connection */if (mysqli_connect_errno()) { printf("Connect failed: %s\n", mysqli_connect_error()); exit();}if ($result = $mysqli->query("SELECT * FROM City ORDER BY ID LIMIT 1")) { /* determine number of fields in result set */ $field_cnt = $result->field_count; printf("Result set has %d fields.\n", $field_cnt); /* close result set */ $result->close();}/* close connection */$mysqli->close();?>
Example #2 过程化风格
<?php$link = mysqli_connect("localhost", "my_user", "my_password", "world");/* check connection */if (mysqli_connect_errno()) { printf("Connect failed: %s\n", mysqli_connect_error()); exit();}if ($result = mysqli_query($link, "SELECT * FROM City ORDER BY ID LIMIT 1")) { /* determine number of fields in result set */ $field_cnt = mysqli_num_fields($result); printf("Result set has %d fields.\n", $field_cnt); /* close result set */ mysqli_free_result($result);}/* close connection */mysqli_close($link);?>
以上例程会输出：
Result set has 5 fields.
