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mysqli::$field_count

mysqli_field_count

(PHP 5)

mysqli::$field_count -- mysqli_field_countReturns 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

int mysqli_field_count ( mysqli $link )

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.

参数

link

仅以过程化样式:由 mysqli_connect() mysqli_init() 返回的链接标识。

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 ) {
    

    
$result  $mysqli -> store_result ();

    

    
$row  $result -> fetch_row ();

    

    
$result -> close ();
}


$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 )) {
    

    
$result  mysqli_store_result ( $link );

    

    
$row  mysqli_fetch_row ( $result );

    

    
mysqli_free_result ( $result );
}


mysqli_close ( $link );
?>

用户评论:

[#1] dedlfix [2006-07-18 10:26:29]

There are MYSQLI_TYPE_* constants for the type property (listed in http://php.net/manual/en/ref.mysqli.php).

e.g.
<?php
if ($finfo->type == MYSQLI_TYPE_VAR_STRING)
  // a VARCHAR

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