Php/docs/mysqli.field-count
mysqli::$field_count
mysqli_field_count
(PHP 5, PHP 7)
mysqli::$field_count -- mysqli_field_count — Returns the number of columns for the most recent query
说明
面向对象风格
int $mysqli->field_count;
过程化风格
mysqli_field_count
( mysqli $link
) : int
Returns the number of columns for the most recent query on the connection
represented by the link parameter. This function
can be useful when using the mysqli_store_result()
function to determine if the query should have produced a non-empty result
set or not without knowing the nature of the query.
返回值
An integer representing the number of fields in a result set.
范例
Example #1 $mysqli->field_count example
面向对象风格
<?php$mysqli = new mysqli("localhost", "my_user", "my_password", "test");$mysqli->query( "DROP TABLE IF EXISTS friends");$mysqli->query( "CREATE TABLE friends (id int, name varchar(20))");$mysqli->query( "INSERT INTO friends VALUES (1,'Hartmut'), (2, 'Ulf')");$mysqli->real_query("SELECT * FROM friends");if ($mysqli->field_count) { /* this was a select/show or describe query */ $result = $mysqli->store_result(); /* process resultset */ $row = $result->fetch_row(); /* free resultset */ $result->close();}/* close connection */$mysqli->close();?>
过程化风格
<?php$link = mysqli_connect("localhost", "my_user", "my_password", "test");mysqli_query($link, "DROP TABLE IF EXISTS friends");mysqli_query($link, "CREATE TABLE friends (id int, name varchar(20))");mysqli_query($link, "INSERT INTO friends VALUES (1,'Hartmut'), (2, 'Ulf')");mysqli_real_query($link, "SELECT * FROM friends");if (mysqli_field_count($link)) { /* this was a select/show or describe query */ $result = mysqli_store_result($link); /* process resultset */ $row = mysqli_fetch_row($result); /* free resultset */ mysqli_free_result($result);}/* close connection */mysqli_close($link);?>
