PHP 意外T_VARIABLE mysqli OOP 编程

Question

我收到以下错误：

解析错误：语法错误、意外的"$this"(T_VARIABLE(/home2/totyaszerver/public_html/autoszallitoberles.hu/db.php on line 12.

我检查了分号，括号，但没有发现任何遗漏。我真的很沮丧，因为我知道我错过了一些东西，但我不知道是什么。

谢谢你帮助我！

<?php
class KRDB{
private $DB_NAME = "####################";
private $DB_ADDRESS = "localhost";
private $DB_USERNAME = "###############";
private $DB_PASSWORD = '#############';
private $krdb = "";
function KRDB()
{
$this->krdb = new mysqli($this->DB_ADDRESS, //I get the error here//$this->DB_USERNAME, $this->DB_PASSWORD, $this->DB_NAME);
if ($this->krdb->connect_errno) {
    echo "Failed to connect to MySQL: " . $this->krdb->connect_error;
exit();
}
}
function Update($table, $field, $data, $where = [{}]){
$generatedWhere = $this->generateWhere($where);
$sql = sprintf("UPDATE %s SET %s = '%s' WHERE %s", $table, $field, $data, $generatedWhere);
if ($this->krdb->query($sql) === TRUE) {
return true;
}
else{
return false;
}
}
function Delete($table, $where = [{}]){
$generatedWhere = $this->generateWhere($where);
$sql = sprintf("DELETE FROM %s WHERE %s", $table, $generatedWhere);
if ($this->krdb->query($sql) === TRUE) {
return true;
}
else{
return false;
}
}
function Insert($table, $data)
{
$generatedFields = "";
$generatedData = "";
for ($i=0; $i < count($data); $i) {
$generatedFields .= sprintf(" %s ", $data[$i][0]);
$generatedData .= "'" . $data[$i][1] . "'";
if($i != count($data)-1)
{
$generatedFields .= ", ";
$generatedData .= ", ";
}
}
$sql = "INSERT INTO %s(%s) VALUES(%s)";
if ($this->krdb->query($sql) === TRUE) {
return true;
}
else{
return false;
}
}
private function generateWhere($where)
{
$generatedWhere = "";
for ($i=0; $i < count($where); $i) {
$generatedWhere .= sprintf(" %s = '%s' ", $where[$i][0], $where[$i][1]);
if($i != count($where)-1)
{
$generatedWhere .= " " . $where[$i][2] . " ";
}
}
return $generatedWhere;
}
function Select($table, $where, $fields = "*"){
$generatedWhere = $this->generateWhere($where);
$sql = sprintf("SELECT %s FROM %s WHERE %s", $fields, $table, $generatedWhere);
$result = $this->krdb->query($sql);
$rows = [];
while($row = $result->fetch_assoc())
{
$rows[] = $row;
}
return $rows;
}
function Count($table, $field, $where = [{}])
{
$generatedWhere = $this->generateWhere($where);
$sql = sprintf("SELECT COUNT(%s) FROM %s WHERE %s", $field, $table, $generatedWhere);
$result = $this->krdb->query($sql);
$fieldC = sprintf("COUNT(%s)", $field);
while($row = $result->fetch_assoc())
{
return $row[$fieldC];
}
}
}
?>

Answer 1

我可能是错的，但我的声誉不够高，无法发表抱歉，但我认为这个函数类会在连接信息之后开始，即

<?php
private $DB_NAME = "####################";
private $DB_ADDRESS = "localhost";
private $DB_USERNAME = "###############";
private $DB_PASSWORD = '#############';
private $krdb = "";
class KRDB{
function KRDB()
{
$this->krdb = new mysqli($this->DB_ADDRESS, //I get the error here//$this->DB_USERNAME, $this->DB_PASSWORD, $this->DB_NAME);
if ($this->krdb->connect_errno) {
echo "Failed to connect to MySQL: " . $this->krdb->connect_error;
exit();
}
}
function Update($table, $field, $data, $where = [{}]){
$generatedWhere = $this->generateWhere($where);
$sql = sprintf("UPDATE %s SET %s = '%s' WHERE %s", $table, $field, $data, $generatedWhere);
if ($this->krdb->query($sql) === TRUE) {
return true;
}
else{
return false;
}
}
function Delete($table, $where = [{}]){
$generatedWhere = $this->generateWhere($where);
$sql = sprintf("DELETE FROM %s WHERE %s", $table, $generatedWhere);
if ($this->krdb->query($sql) === TRUE) {
return true;
}
else{
return false;
}
}
function Insert($table, $data)
{
$generatedFields = "";
$generatedData = "";
for ($i=0; $i < count($data); $i) {
$generatedFields .= sprintf(" %s ", $data[$i][0]);
$generatedData .= "'" . $data[$i][1] . "'";
if($i != count($data)-1)
{
$generatedFields .= ", ";
$generatedData .= ", ";
}
}
$sql = "INSERT INTO %s(%s) VALUES(%s)";
if ($this->krdb->query($sql) === TRUE) {
return true;
}
else{
return false;
}
}
private function generateWhere($where)
{
$generatedWhere = "";
for ($i=0; $i < count($where); $i) {
$generatedWhere .= sprintf(" %s = '%s' ", $where[$i][0], $where[$i][1]);
if($i != count($where)-1)
{
$generatedWhere .= " " . $where[$i][2] . " ";
}
}
return $generatedWhere;
}
function Select($table, $where, $fields = "*"){
$generatedWhere = $this->generateWhere($where);
$sql = sprintf("SELECT %s FROM %s WHERE %s", $fields, $table, $generatedWhere);
$result = $this->krdb->query($sql);
$rows = [];
while($row = $result->fetch_assoc())
{
$rows[] = $row;
}
return $rows;
}
function Count($table, $field, $where = [{}])
{
$generatedWhere = $this->generateWhere($where);
$sql = sprintf("SELECT COUNT(%s) FROM %s WHERE %s", $field, $table, $generatedWhere);
$result = $this->krdb->query($sql);
$fieldC = sprintf("COUNT(%s)", $field);
while($row = $result->fetch_assoc())
{
return $row[$fieldC];
}
}
}
?>

Answer 2

你能更准确地说明你遇到的问题吗？我尝试运行您的代码，看起来很好。这是结果

class KRDB{
private $DB_NAME = "test_db";
private $DB_ADDRESS = "localhost";
private $DB_USERNAME = "test";
private $DB_PASSWORD = 'test';
private $krdb = "";
function KRDB()
{
$this->krdb = new mysqli($this->DB_ADDRESS, $this->DB_USERNAME, $this->DB_PASSWORD, $this->DB_NAME);
if ($this->krdb->connect_errno) {
echo "Failed to connect to MySQL: " . $this->krdb->connect_error;
exit();
}   
else {
print_r($this->krdb);
}
}
}
$a = new KRDB();
// And it is working
mysqli Object
(
[affected_rows] => 0
[client_info] => mysqlnd 5.0.12-dev - 20150407 - $Id: b5c5906d452ec590732a93b051f3827e02749b83 $
[client_version] => 50012
[connect_errno] => 0
[connect_error] => 
[errno] => 0
[error] => 
[error_list] => Array
(
)
[field_count] => 0
[host_info] => Localhost via UNIX socket
[info] => 
[insert_id] => 0
[server_info] => 5.7.18-0ubuntu0.16.04.1
[server_version] => 50718
[stat] => Uptime: 105254  Threads: 1  Questions: 15360  Slow queries: 0  Opens: 4770  Flush tables: 1  Open tables: 411  Queries per second avg: 0.145
[sqlstate] => 00000
[protocol_version] => 10
[thread_id] => 425
[warning_count] => 0
)