PHP mysqli_field_seek()用法及代码示例

定义和用法

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

mysqli_field_seek() 函数接受一个结果对象和一个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字段。

用法

mysqli_field_seek($result, $field);

参数

Sr.No	参数及说明
1	result(Mandatory) 这是一个表示结果对象的标识符。
2	field(Mandatory) 这是一个整数值，表示您需要将给定结果对象中的字段查找移动到的字段编号。

返回值

PHP mysqli_field_seek() 函数返回一个布尔值，即成功时为 TRUE，失败时为 FALSE。

PHP版本

这个函数最初是在 PHP 版本 5 中引入的，适用于所有后续版本。

示例

以下示例演示了 mysqli_field_seek() 函数的用法(程序风格) -

<?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");

   //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

在面向对象的风格中，这个函数的语法是 $result->field_seek;以下是面向对象样式 $minus 中此函数的示例；

<?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();

   //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