Package database MySQL, mysqli

<?php

Header ("Content-type:text/html;charset=utf-8");

Class db{
private static property
private static $dbcon = false;
Private method of construction
Private function __construct ($dbname) {
$dbcon = @mysql_connect (' 127.0.0.1 ', ' root ', ' root ');
mysql_select_db ($dbname, $dbcon) or Die ("MySQL connect error");
mysql_query ("Set names UTF8", $dbcon);
}
Private Cloning method
Private Function __clone () {}
public static methods, database connection objects
public static function getinstance ($dbname) {
if (self:: $dbcon = = False) {
Self:: $dbcon = new db ($dbname);
}
Return self:: $dbcon;
}
/**
* EXECUTE statement
* @param $sql
* @return Source
*/
Public Function Query ($sql) {
return mysql_query ($sql);
}
/**
* Query A field, such as SELECT COUNT (*), select username
* @param $sql
* @return string or int
*/
Public Function GetOne ($sql) {
$query = $this->query ($sql);
Return mysql_result ($query, 0);
}
/**
* Get a row of records
* @param $sql
* @return Array one-dimensional
*/
Public Function GetRow ($sql, $type = ' Assoc ') {
$query = $this->query ($sql);
if (!in_array ($type, Array ("Assoc", "Array", "Row"))) {
Die ("mysql_query error");
}
$functionname = "Mysql_fetch_". $type;
Return $functionname ($query);
}
/**
* Preconditions: Get a record from a resource
* @param $query Source
* @return Array one-dimensional
*/
Public Function Getrowfromsource ($query, $type = "Assoc") {
if (!in_array ($type, Array ("Assoc", "Array", "Row"))) {
Die ("mysql_query error");
}
$functionname = "Mysql_fetch_". $type;
Return $functionname ($query);
}
/**
* Get all records
* @param $sql
* @return Array Two-dimensional
*/
Public Function GetAll ($sql) {
$query = $this->query ($sql);
$list = Array ();
while ($row = $this->getrowfromsource ($query)) {
$list [] = $row;
}
return $list;
}
/*
* New Data method
* @param1 $table, $data table name data
* @return Last added operation to generate ID value
*/
Public Function Insert ($table, $data) {
Iterate through an array to get the values of each field and field
$kstr = ";
$vstr = ";
foreach ($data as $key = = $val) {
$key is the field name, $val is the corresponding value
$kstr = $key. ",";
$vstr = "' $val ',";
}
$kstr = RTrim ($kstr, ', ');
$vstr = RTrim ($vstr, ', ');
The SQL statement added
$sql = "INSERT into $table ($KSTR) VALUES ($VSTR)";
Perform
$this->query ($sql);
Returns the last increment of the operation to generate the ID value
return $this->getinsertid ();
}
/*
* Delete a data method
* @param1 $table, $where =array (' id ' = ' 1 ') Table name condition
* @return The number of rows affected
*/
Public Function Deleteone ($table, $where) {
if (Is_array ($where)) {
foreach ($where as $key = = $val) {
$condition = $key. ' = '. $val;
}
} else {
$condition = $where;
}
$sql = "Delete from $table where $condition";
$this->query ($sql);
Returns the number of rows affected
return Mysql_affected_rows ();
}
/*
* Delete multiple data methods
* @param1 $table, $where table name conditions
* @return The number of rows affected
*/
Public Function DeleteAll ($table, $where) {
if (Is_array ($where)) {
foreach ($where as $key = = $val) {
if (Is_array ($val)) {
$condition = $key. ' In ('. Implode (', ', $val). ') ';
} else {
$condition = $key. ' = '. $val;
}
}
} else {
$condition = $where;
}
$sql = "Delete from $table where $condition";
$this->query ($sql);
Returns the number of rows affected
return Mysql_affected_rows ();
}
/*
* Modify Data method
* @param1 $table, $data, $where table name data conditions
* @return The number of rows affected
*/
Public Function Update ($table, $data, $where) {
Iterate through an array to get the values of each field and field
$str = ";
foreach ($data as $key = = $v) {
$str. = "$key = ' $v ',";
}
$str =rtrim ($str, ', ');
Modified SQL statements
$sql = "Update $table set $str where $where";
$this->query ($sql);
Returns the number of rows affected
return Mysql_affected_rows ();
}
/**
* Get the ID of the data just inserted
* @return int
*/
Public Function Getinsertid () {
return mysql_insert_id ();
}
/**
* Print_r Print Data
*/
Public function P ($arr) {
echo "<pre>";
Print_r ($arr);
echo "</pre>";
}
/**
* Var_dump Print Data
*/
Public Function V ($arr) {
echo "<pre>";
Var_dump ($arr);
echo "</pre>";
}


}
$dbname = ' Yii2_project ';
$db = Db::getinstance ($dbname);
where article_id=1
$sql = "SELECT * from article";
$arr = $db->getall ($sql);
$db->p ($arr);

<?php

Header
Header (' Content-type:text/html;charset=utf-8 ');

Class DB {
Defining properties
private $host;//Host Name
private $port;//Port number
private $name;//user name
private $pass;//password
private $dbname;//Database name
private $charset;//Set character sets
private $link;//Connect to Database
private static $instance;
Initializing constructors
Private Function __construct ($arr = Array ()) {
$this->host = isset ($arr [' Host '])? $arr [' Host ']: ' localhost ';
$this->port = isset ($arr [' Port '])? $arr [' Port ']: ' 3306 ';
$this->name = isset ($arr [' name '])? $arr [' name ']: ' Root ';
$this->pass = isset ($arr [' Pass '])? $arr [' Pass ']: ' Root ';
$this->dbname = isset ($arr [' dbname '])? $arr [' dbname ']: ' Yii2_project ';
$this->charset = isset ($arr [' CharSet '])? $arr [' CharSet ']: ' UTF8 ';
Connecting to a database
$this->db_connect ();
Select Database
$this->db_usedb ();
Set character sets
$this->db_charset ();
}
Connecting to a database
Private Function Db_connect () {
Host Name: port number User name password
$this->link = Mysqli_connect ($this->host. ': ' $this->port, $this->name, $this->pass);
Connection failed
if (! $this->link) {
Echo ' Database connection failed <br> ';
Echo ' Error code is: '. Mysqli_errno ($this->link). ' <br> ';
The echo ' error message is: '. Mysqli_error ($this->link). ' <br> ';
Exit
}
}
Select Database
Private Function Db_usedb () {
Mysqli_query ($this->link, "Use {$this->dbname}");
}
Set character sets
Private Function Db_charset () {
Mysqli_query ($this->link, "set names {$this->charset}");
}
Privatization of cloning functions to prevent external cloning of objects
Private Function __clone ()
{
}

Single Access Unified portal
public static function getinstance ()
{
if (! ( Self:: $instance instanceof Self))
{
Self:: $instance = new DB ();
}
Return self:: $instance;
}
Methods for executing SQL statements
Private Function Db_query ($sql) {
$res = Mysqli_query ($this->link, $sql);
if (! $res) {
echo ' SQL statement has error <br> ';
Echo ' Error code is: '. Mysqli_errno ($this->link). ' <br> ';
The echo ' error message is: '. Mysqli_error ($this->link). ' <br> ';
Exit
}
return $res;//Return data successfully
}
Add action
Public Function Db_insert ($sql) {
$this->db_query ($sql);
Returns the last ID that was added
return mysql_insert_id ();
}
Delete operation
Public Function Db_delete ($sql) {
$this->db_query ($sql);
Returns the number of rows affected
Return Mysqli_affected_rows ($this->link);
}
Modify Operation
Public Function Db_update ($sql) {
$this->db_query ($sql);
Returns the number of rows affected
Return Mysqli_affected_rows ($this->link);
}
View a single piece of data
Public Function Db_getone ($sql) {
$res = $this->db_query ($sql);
Return data
Return Mysqli_fetch_assoc ($res);
}
View more than one piece of data
Public Function Db_getall ($sql) {
$res = $this->db_query ($sql);
$arr = Array ();
while ($row = Mysqli_fetch_assoc ($res)) {
$arr [] = $row;
}
Return data
return $arr;
}

}

Package database MySQL, mysqli