在Mysql中选定的数据库中创建表时出错

Question

我试图在创建的数据库中创建表时遇到错误A link to the server could not be established in /var/www/Test.php on line 25和mysql_select_db(): Access denied for user 'pass'@'localhost' (using password: NO) in /var/www/Test.php on line 25。

我的代码：

<?php 
    $con = mysqli_connect("localhost","root","pass"); 
    connection to mysql server 
    //checking the connection 
    if(mysqli_connect_errno($con)) 
     { 
     echo "Sorry!Failed to connect Mysql" . mysqli_connect_error(); 
     } 
     $sql = "CREATE DATABASE viral_coff"; 
    if(mysqli_query($con,$sql)) 
    echo "database Created Successfully!"; 
    else 
    echo "error in creating the database" . mysqli_error($con); 
    mysql_select_db('viral_coff') or die(mysql_error());; 
    $tab = ' CREATE TABLE retention('. 
      ' playing-date DATE ,' . 
      ' that-day INT ,' . 
      ' 1_day INT ,' . 
      ' 3_days INT ,' . 
      ' 7_days INT ,' . 
      ' 31_days INT ,)' ; 
    if(mysqli_query($con,$tab)) 
    echo "Created Tables"; 
    else 
    echo "Error creating table" . mysqli_error($con); 
    mysqli_close($con) 
    ?> 

我到底做错了什么？

Answer 1

您在混合mysql_*函数与mysqli_*函数。 你当然不能！

您需要使用mysqli_select_db()代替mysql_select_db()

而且学会把一些支架上你的if语句，从而可以肯定的里面是什么，该语句的外100％。

Answer 2

mysql_和mysqli_函数不能很好地协同工作。选择一个并与他们合作，而不是两个。

Answer 3

您正在移除密码。

<?php 
define('Hostname','localhost'); 
define('Username','root'); 
define('Password',''); 
define('DB_Name','viral_coff'); 

$con=mysqli_connect(Hostname,Username,Password); 
// Check connection 
if (mysqli_connect_errno()) 
{ 
    echo "Failed to connect to MySQL: " . mysqli_connect_error(); 
} 

// Create database 
$sql="CREATE DATABASE ".DB_Name; 
if (mysqli_query($con,$sql)) 
{ 
    echo "Database ".DB_Name." created successfully"; 
} 
else 
{ 
    echo "Error creating database: " . mysqli_error($con); 
} 

$con = mysqli_connect(Hostname,Username,Password,DB_Name); 
// Check connection 
if (mysqli_connect_errno()) 
{ 
    echo "Failed to connect to MySQL: " . mysqli_connect_error(); 
} 

// Create table 
$sql = "CREATE TABLE retention(playing_date DATE, that_day INT, 1_day INT , 3_days INT ,7_days INT , 31_days INT)"; 

// Execute query 
if (mysqli_query($con,$sql)) 
{ 
    echo "Table retention created successfully"; 
} 
else 
{ 
    echo "Error creating table: " . mysqli_error($con); 
} 
?>