PHP mysqli_fetch_field()用法及代碼示例

定義和用法

PHP 結果對象(屬於 mysqli_result 類)表示 MySQL 結果，由 SELECT 或 DESCRIBE 或 EXPLAIN 查詢返回。

mysqli_fetch_field()函數接受一個結果對象作為參數，並以對象的形式返回下一列/字段的定義信息。

用法

mysqli_fetch_field($result);

參數

Sr.No	參數及說明
1	result(Mandatory) 這是一個表示結果對象的標識符。

返回值

PHP mysqli_fetch_field() 函數返回一個對象，該對象包含給定結果中字段的定義信息。如果沒有信息，此函數返回 FALSE。

返回的對象包含以下屬性 $minus;

• name

• orgname

• table

• orgtable

• max_length

• length

• charsetnr

• flags

• type

• decimals

PHP版本

這個函數最初是在 PHP 版本 5 中引入的，適用於所有後續版本。

示例

以下示例演示了 mysqli_fetch_field() 函數的用法(程序風格) -

<?php
   $con = mysqli_connect("localhost", "root", "password", "mydb");

   mysqli_query($con, "CREATE TABLE myplayers(ID INT, First_Name VARCHAR(255), Last_Name VARCHAR(255), Place_Of_Birth VARCHAR(255), Country VARCHAR(255))");
   print("Table Created.....\n");
   mysqli_query($con, "INSERT INTO myplayers values(1, 'Sikhar', 'Dhawan', 'Delhi', 'India')");
   mysqli_query($con, "INSERT INTO myplayers values(2, 'Jonathan', 'Trott', 'CapeTown', 'SouthAfrica')");
   mysqli_query($con, "INSERT INTO myplayers values(3, 'Kumara', 'Sangakkara', 'Matale', 'Srilanka')");
   print("Record Inserted.....\n");

   //Retrieving the contents of the table
   $res = mysqli_query($con, "SELECT * FROM myplayers");

   //Fetching the fields
   while($info = mysqli_fetch_field($res)){
      //Current field
      $currentfield = mysqli_field_tell($res);
      print("Current Field:".$currentfield."\n");
      print("Name:".$info->name."\n");
      print("Type:".$info->type."\n");
   }

   //Closing the statement
   mysqli_free_result($res);

   //Closing the connection
   mysqli_close($con);
?>

這將產生以下結果 -

Table Created.....
Record Inserted.....
Current Field:1
Name:ID
Type:3
Current Field:2
Name:First_Name
Type:253
Current Field:3
Name:Last_Name
Type:253
Current Field:4
Name:Place_Of_Birth
Type:253
Current Field:5
Name:Country
Type:253

示例

在麵向對象的風格中，這個函數的語法是 $result->fetch_field;以下是麵向對象樣式 $minus 中此函數的示例；

<?php
   //Creating a connection
   $con = new mysqli("localhost", "root", "password", "mydb");

   $con -> query("CREATE TABLE Test(Name VARCHAR(255), AGE INT)");
   $con -> query("insert into Test values('Raju', 25),('Rahman',  30),('Sarmista', 27)");
   print("Table Created.....\n");

   $stmt = $con -> prepare( "SELECT * FROM Test WHERE Name in(?, ?)");
   $stmt -> bind_param("ss", $name1, $name2);
   $name1 = 'Raju';
   $name2 = 'Rahman';

   //Executing the statement
   $stmt->execute();

   //Retrieving the result
   $result = $stmt->get_result();

   //Current Field
   while($info = $result->fetch_field()){
      $field = $result->current_field;
      print("Current Field:".$field."\n");
      print("Field Name:".$info->name."\n");
   }

   //Closing the statement
   $stmt->close();

   //Closing the connection
   $con->close();
?>

這將產生以下結果 -