mysqli_result::$field_count()
(PHP 5, PHP 7)
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.
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。
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.
参见
- mysqli_fetch_field() Returns the next field in the result set