PHP connection MySQL database and delete and change

1. Connect MySQL database $conn = new Mysqli ($host, $user, $password);

 $conn, query (' Set names UTF8 '); //Set character encoding to avoid storing Chinese data garbled
$conn-select_db (' db '); //Select the database (db) you have set up

1.1 determine connection status
If (! $conn) {
Die (" Database connection Exception ");
}

 //Database creation
$db = "CREATE Database db";
if ($conn, query ($db)) {
echo "successfully created database ";
  }else{
echo "Create failed ";
}

 //data table creation
 $table = "CREATE TABLE table_name (
  ID int (TEN) unsigned auto_increment unique primary key,
   user varchar (+) not NULL
);";

1.1.1 Adding Data Method 1: Preprocessing statements and binding parameter methods (for execution of multiple query statements)
$table = $conn Prepare ("INSERT into user_table (Id,user) VALUES (NULL,?)"); / Prepare SQL statements
$name = ' Xiao Ming ';
$table-Bind_param ("s", $name); (Type: s, type value), parameter S is string,i to interger,d and double, type value can only be a variable
if ($table, execute () && $conn-affected_rows) {     //Decide whether to add success
echo "Add success";
}else{

}

1.1.1 Add Data Method Two: Directly call the query () method (suitable for a single statement; multiple ";" Separated, using Multi_query () method to query);
$insert = "INSERT into table (name) VALUES (' Hello ')";
if ($conn, query ($insert) && $conn, affected_rows) {  
echo "added successfully";
}else{
echo "Add failed";
}

1.1.2 Delete Data Method 1 call the query () method directly;

$delete = "Delete from user_table where user in (' Zhang San ', ' 1 ') or ID in (1)";//Delete column name of User= ' Zhang San ' or id=1 column name
if ($conn, query ($delete) && $row = $conn affected_rows) {
   "Delete succeeded, altogether: $row". Line ";
}else{
Ehco "Delete Failed";
}

 //1.1.2 Deleting Data Method 2: preprocessing statements and binding parameters
$delete = $conn Prepare ("Delete from user_table where ID in (?) or user in (?); ");
$id = 1;
$name = ' Zhang San ';
$delete-Bind_param (' II ', $id, $name);
if ($delete, execute () && $row = $conn-affected_rows) {
echo "Delete succeeded, altogether: $row". Line ";
}else{
echo "Delete Failed";
}

1.1.3 Change Data Method 1: Direct query () method
$update = "Update user_table set user = ' Miss Liu ' where id = ' 115 ';";
if ($conn, query ($update) && $row = $conn affected_rows) {
echo "Change: $row". " Line ";
}else{
echo "Failed to change";
}

//1.1.3 Change Data Method 2: preprocessing statements and binding parameters
$update = $conn-Prepare ("update user_table set user =?") where id =?; ");
$user = "Miss Huang";
$id = 1;
   $update-Bind_param ("Si", $user, $id);
if ($update, execute () && $row = $conn-affected_rows) {
      echo "Change: $row". " Line ";
       }else{
echo "Failed to change";
}

1.1.4 Query data Method 1: Direct query () method

$select = "Select Id,user from User_table ORDER by User,id DESC";$result = Query ($select), $conn
if ($result-num_rows>0) {//ORDER BY sort desc descending sort
while ($row = $result, Fetch_array ()) {//Loop query and return each statement of the specified condition
      echo "$row [id]: $row [user]<br>";
 }
}else{
           echo " no data  ";
}

1.2 Process-oriented approach
$conn = Mysqli_connect ($this->host, $this, user, $this-password);

Mysqli_query ($conn, ' Set names UTF8 '); Set character encoding to avoid storing Chinese data garbled

mysqli_select_db ($conn, ' db '); //Select the database (db) you have set up

1.2.1 Additions and deletions (similarly above);
That is:mysqli_query () = = $conn query ();

1.3 PDO method (slightly)

PHP connection MySQL database and delete and change