PHP mysqli_field_seek() 函数

定义和用法

PHP 结果对象（类 mysqli_result）表示 MySQL 结果，由 SELECT 或 DESCRIBE 或 EXPLAIN 查询返回。

mysqli_field_seek() 函数接受结果对象和表示字段编号的整数值作为参数，并将给定结果对象的字段查找移动到指定的字段。

语法

mysqli_field_seek($result, $field);

参数

返回值

PHP mysqli_field_seek() 函数返回一个布尔值，如果成功则为 TRUE，如果失败则为 FALSE。

PHP 版本

此函数首次在 PHP 5 版本中引入，并在所有后续版本中有效。

示例

以下示例演示了 mysqli_field_seek() 函数（在过程式风格中）的使用 -

<?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");

   //Moving the seek to 3rd field
   mysqli_field_seek($res, 2);

   //Fetching the fields
   $info = mysqli_fetch_field($res);
   //Current field
   $currentfield = mysqli_field_tell($res);
   print("Current Field: ".$currentfield."\n");
   print("Name: ".$info->name."\n");
   print("Table: ".$info->table."\n");
   print("Max Length: ".$info->max_length."\n");
   print("Flags: ".$info->flags."\n");
   print("Type: ".$info->type."\n");


   //Closing the statement
   mysqli_free_result($res);

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

这将产生以下结果 -

Table Created.....
Record Inserted.....
Current Field: 3
Name: Last_Name
Table: myplayers
Max Length: 10
Flags: 0
Type: 253

示例

在面向对象风格中，此函数的语法为 $result->field_seek; 以下是此函数在面向对象风格中的示例 $minus;

<?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();

   //Moving the seek to the 2nd field
   $result->field_seek(1);

   //Fetching the 2nd field Current Field
   $info = $result->fetch_field();

   $field = $result->current_field;
   print("Current Field: ".$field."\n");
   print("Field Name: ".$info->name."\n");
   print("Field Type: ".$info->type);


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

这将产生以下结果 -

Table Created.....
Current Field: 2
Field Name: AGE
Field Type: 3