field_seek

定義和用法

field_seek() / mysqli_field_seek()函數將字段光標設置為給定的字段偏移量。

實例

例子1 - 面向對像風格

將字段光標設置為結果集中的第二列（"Age"），使用fetch_field() 獲取字段信息，然後打印字段的名稱、表和最大長度：

 <?php
$mysqli = new mysqli ( "localhost" , "my_user" , "my_password" , "my_db" ) ;

if ( $mysqli -> connect_errno ) {
  echo "Failed to connect to MySQL: " . $mysqli -> connect_error ;
  exit ( ) ;
}

$sql = "SELECT Lastname, Age FROM Persons ORDER BY Lastname" ;

if ( $result = $mysqli -> query ( $sql ) ) {

  // 獲取第二列的字段信息
  $result = field_seek ( 1 ) ;
  $fieldinfo = $result -> fetch_field ( ) ;

  printf ( "Name: %s\n" , $fieldinfo -> name ) ;
  printf ( "Table: %s\n" , $fieldinfo -> table ) ;
  printf ( "Max. Len: %d\n" , $fieldinfo -> max_length ) ;
  $result -> free_result ( ) ;
}

$mysqli -> close ( ) ;
?>

例子2 - 過程式風格

將字段光標設置為結果集中的第二列（"Age"），使用mysqli_fetch_field() 獲取字段信息，然後打印字段的名稱、表和最大長度：

 <?php
$con = mysqli_connect ( "localhost" , "my_user" , "my_password" , "my_db" ) ;

if ( mysqli_connect_errno ( ) ) {
  echo "Failed to connect to MySQL: " . mysqli_connect_error ( ) ;
  exit ( ) ;
}

$sql = "SELECT Lastname, Age FROM Persons ORDER BY Lastname" ;

if ( $result = mysqli_query ( $con , $sql ) ) {

  // 獲取第二列的字段信息
  mysqli_field_seek ( $result , 1 ) ;
  $fieldinfo = mysqli_fetch_field ( $result ) ;

  printf ( "Name: %s\n" , $fieldinfo -> name ) ;
  printf ( "Table: %s\n" , $fieldinfo -> table ) ;
  printf ( "max. Len: %d\n" , $fieldinfo -> max_length ) ;
  mysqli_free_result ( $result ) ;
}

mysqli_close ( $con ) ;
?>