PHP mysqli_stmt_fetch() 函数

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定义和用法

您可以创建一个预处理语句，在使用 mysqli_prepare() 函数的情况下，该语句包含参数标记（“？”）。准备语句后，您需要使用 mysqli_stmt_bind_param() 函数将值绑定到已创建语句的参数。

同样，您可以使用 mysqli_stmt_bind_result() 函数将结果集的列绑定到所需的变量。

绑定列后，如果您调用 mysqli_stmt_fetch() 函数，它会将结果的列提取到指定的变量中。

语法

mysqli_stmt_fetch($stmt);

参数

返回值

PHP mysqli_stmt_fetch() 函数在提取数据时返回 TRUE，在发生错误时返回 FALSE，并且在结果中没有更多行时返回 NULL。

PHP 版本

此函数最早在 PHP 5 版本中引入，并在所有后续版本中均有效。

示例

以下示例演示了 mysqli_stmt_fetch() 函数（以过程式风格）的用法：

<?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')");
   print("Record Inserted.....\n");

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

   //Executing the statement
   mysqli_stmt_execute($stmt);

   //Binding values in result to variables
   mysqli_stmt_bind_result($stmt, $id, $fname, $lname, $pob, $country);

   while (mysqli_stmt_fetch($stmt)) {
      print("Id: ".$id."\n");
      print("fname: ".$fname."\n");
      print("lname: ".$lname."\n");
      print("pob: ".$pob."\n");
      print("country: ".$country."\n");
      print("\n");

   }
   //Closing the statement
   mysqli_stmt_close($stmt);

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

这将产生以下结果：

Table Created.....
Record Inserted.....
Id: 1
fname: Sikhar
lname: Dhawan
pob: Delhi
country: India

Id: 2
fname: Jonathan
lname: Trott
pob: CapeTown
country: SouthAfrica

示例

在面向对象风格中，此函数的语法为 $stmt->fetch(); 以下是此函数在面向对象风格中的示例：

<?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';
   print("Records Deleted.....\n");

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

   //Binding variables to resultset
   $stmt->bind_result($name, $age);
   while ($stmt->fetch()) {
      print("Name: ".$name."\n");
      print("Age: ".$age."\n");
   }

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

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

这将产生以下结果：

Table Created.....
Records Deleted.....
Name: Raju
Age: 25
Name: Rahman
Age: 30

示例

以下示例使用 mysqli_stmt_bind_result() 和 mysqli_stmt_fetch() 函数提取 DESCRIBE 查询的结果：

<?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");

   //Description of the table
   $stmt = mysqli_prepare($con, "DESC myplayers");

   //Executing the statement
   mysqli_stmt_execute($stmt);

   //Binding values in result to variables
   mysqli_stmt_bind_result($stmt, $field, $type, $null, $key, $default, $extra);

   while (mysqli_stmt_fetch($stmt)) {
      print("Field: ".$field."\n");
      print("Type: ".$type."\n");
      print("Null: ".$null."\n");
      print("Key: ".$key."\n");
      print("Default: ".$default."\n");
      print("Extra: ".$extra."\n");
      print("\n");
   }

   //Closing the statement
   mysqli_stmt_close($stmt);

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

这将产生以下结果：

Table Created.....
Field: ID
Type: int(11)
Null: YES
Key:
Default:
Extra:

Field: First_Name
Type: varchar(255)
Null: YES
Key:
Default:
Extra:

Field: Last_Name
Type: varchar(255)
Null: YES
Key:
Default:
Extra:

Field: Place_Of_Birth
Type: varchar(255)
Null: YES
Key:
Default:
Extra:

Field: Country
Type: varchar(255)
Null: YES
Key:
Default:
Extra:

示例

以下示例使用 mysqli_stmt_bind_result() 和 mysqli_stmt_fetch() 函数提取 SHOW TABLES 查询的结果：

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

   //Selecting the database
   mysqli_query($con, "CREATE DATABASE NewDatabase");
   mysqli_select_db($con, "NewDatabase");

   //Creating tables
   mysqli_query($con, "CREATE TABLE test1(Name VARCHAR(255), Age INT)");
   mysqli_query($con, "CREATE TABLE test2(Name VARCHAR(255), Age INT)");
   mysqli_query($con, "CREATE TABLE test3(Name VARCHAR(255), Age INT)");
   print("Tables Created.....\n");

   //Description of the table
   $stmt = mysqli_prepare($con, "SHOW TABLES");

   //Executing the statement
   mysqli_stmt_execute($stmt);

   //Binding values in result to variables
   mysqli_stmt_bind_result($stmt, $table_name);

   print("List of tables in the current database: \n");
   while (mysqli_stmt_fetch($stmt)) {
      print($table_name."\n");
   }

   //Closing the statement
   mysqli_stmt_close($stmt);

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

这将产生以下结果：

Tables Created.....
List of tables in the current database:
test1
test2
test3