When my shared hosting upgrade mysql version from 5 to 8, many of my php websites cannot be openned.

I checked php error log saw many syntax become error.

So here are the fixes of syntax :
Codeigniter : Library > common.php
Old variable $where = "Where id=123" need to modify it become : $where = "id=123" So we need to remove "Where" from variable. $where2 = substr($where,6);


Cannot combine Select, Table, Where in 1 query.
Must saperate Select, Table, Where.

//Problem code : function getSelectedOneField($select,$table,$where) { $q = "select $select from $table $where"; $query=$this->CI->db->query($q); $result = $query->row_array(); return $result[$select]; } //Solution code : function getSelectedOneField($select, $table, $where) { $this->CI->db->select($select); $this->CI->db->from($table); $where2 = substr($where,6); $this->CI->db->where($where2); $query = $this->CI->db->get(); $result = $query->row_array(); if ($result) { return $result[$select]; } return null; // Return an appropriate value if no result is found }


Cannot write query join tables in 1 query (library/common.php).
Must saperate join tables.

// Problem codes : $total_invested = $this->getSelectedOneField("SUM(p.investment_capital) AS abc", "tbl_product_order o LEFT JOIN tbl_package_master p ON p.id = o.package_id", "WHERE o.status = 3 AND o.user_id = '" . $user_id . "'"); // Solution codes : function getSelectedOneFieldJoinTbl($select, $table, $where, $join_table, $join_condition) { $this->CI->db->select($select); $this->CI->db->from($table); $where2 = substr($where,6); $this->CI->db->where($where2); if($join_table && $join_condition) { $this->CI->db->join($join_table, $join_condition); } $query = $this->CI->db->get(); $result = $query->row_array(); if ($result) { return $result[$select]; } return null; // Return an appropriate value if no result is found } $total_invested = $this->getSelectedOneFieldJoinTbl( "SUM(p.investment_capital)", "tbl_product_order o", "WHERE o.status = 3 AND o.user_id = '" . $user_id . "'", "tbl_package_master p", // $join_table "p.id = o.package_id" // $join_condition );


Must saperate Group_By :

function getAllRecJoinTblGroupBy($select, $table, $join_table, $join_condition, $where, $group_by) { $this->CI->db->select($select); $this->CI->db->from($table); if($join_table && $join_condition) { $this->CI->db->join($join_table, $join_condition); } $where2 = substr($where,6); $this->CI->db->where($where2); $group_by2 = substr($group_by,8); $this->CI->db->group_by($group_by2); $query = $this->CI->db->get(); $result = $query->row_array(); } $total_direct_all_child1 = $this->getAllRecJoinTblGroupBy( "u.user_id, u.username, u.unique_code, u.user_email, p.id, p.status", "tbl_user_master u", "tbl_product_order p", "p.user_id = u.user_id", "WHERE u.sponsor_id = '".$total_direct_child['user_id']."' AND u.status = 1 AND u.user_type = 2 AND p.status = 3", "GROUP_BY u.user_id" );


Must saperate Order_By :

function getAllRecOrderBy($select,$table,$where,$order_by=null) // GET ALL RECORDS WITH SELECT STRING { $where2 = substr($where,6); $this->CI->db->select($select); $this->CI->db->from($table); $this->CI->db->where($where2); $this->CI->db->order_by($order_by); $query = $this->CI->db->get(); $result = $query->row_array(); } $member = $this->common->getAllRecOrderBy( "user_id,username,first_name, last_name, rank", "tbl_user_master", "WHERE status != 3 AND user_type = 2", "first_name", "ASC", "last_name", "ASC" );


Php pdo : //Problem Code: $sql = 'SELECT payment_date, SUM(price), SUM(profit) FROM sale WHERE seller_id = ? && Year(payment_date) = ? GROUP BY Month(payment_date) DESC'; $q = $conn->prepare($sql); $result = $q->execute(array($user_id, $selected_year)); //Solution Code: $sql = 'SELECT payment_date, SUM(price) AS price_total, SUM(profit) AS profit_total FROM sale WHERE seller_id = :spender_id && Year(payment_date) = :payMYear GROUP BY Month(payment_date) ORDER BY payment_date DESC'; $stmt = $conn->prepare($sql); $stmt->bindParam(':spender_id', $user_id, PDO::PARAM_INT); $stmt->bindParam(':payMYear', $selected_year); $stmt->execute();
select and display data from database :
important at :
1) try
2) {$row['id']}
try { $dbhost = "localhost"; $dbusername = "aekcom_zac1987"; $dbpassword = "h~m_*MqTH*pD"; $dbname = "aekcom_idea4better"; $pdo = new PDO("mysql:host=$dbhost;charset=utf8mb4;dbname=$dbname", $dbusername, $dbpassword); $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); $sql = "SELECT * FROM ckeditorSummernote"; $stmt = $pdo->prepare($sql); $stmt->execute(); $result = $stmt->fetchAll(PDO::FETCH_ASSOC); foreach ($result as $row) { echo "<tr>"; echo "<td>{$row['id']}</td>"; echo "<td>{$row['title']}</td>"; echo "<td>{$row['content']}</td>"; echo "</tr>"; } } catch (PDOException $e) { echo "Error: " . $e->getMessage(); } $pdo = null;
Join 2 tables + Group_by + Order_by :

function getSelectedOneFieldJoin2TblGroupOrder($select, $table, $where, $join_table1, $join_condition1, $join_table2, $join_condition2, $order_by=null, $group_by=null) { $this->CI->db->select($select); $this->CI->db->from($table); $where2 = substr($where,6); $this->CI->db->where($where2); if($join_table1 && $join_condition1) { $this->CI->db->join($join_table1, $join_condition1, 'left'); } if($join_table2 && $join_condition2) { $this->CI->db->join($join_table2, $join_condition2, 'left'); } $this->CI->db->order_by($order_by); $group_by2 = substr($group_by,8); $this->CI->db->group_by($group_by2); $query = $this->CI->db->get(); $result = $query->result_array(); if ($result) { return $result; } return null; // Return an appropriate value if no result is found }


If sql got error then check this two things :

$query = $this->CI->db->get(); $result = $query->result_array(); $query->result_array(); //get many rows of records so use foreach loop. $query->row_array(); //get only 1 record.


Limit : (Must delete limit if no use limit, otherwise no result will show)

function getAllRec2($select, $table, $where, $order_by=null, $limit=null) { $this->CI->db->select($select); $this->CI->db->from($table); $where2 = substr($where,6); $this->CI->db->where($where2); $this->CI->db->order_by($order_by); $limit2 = substr($limit,6); $this->CI->db->limit($limit2); $query = $this->CI->db->get(); return $query->result_array(); } $res_data[]=$res2=$this->common->getAllRec2( " 'New Member Registered' as activity_title, u.created_on as created_on, concat(u.first_name, ' ', u.last_name) as created_by", "tbl_user_master u", "WHERE u.status != 2 and u.status != 0 ", //and u.created_on >= DATE_ADD(CURDATE(), INTERVAL -3 DAY) "u.created_on", "ASC", "Limit 5" );


php variable in WHERE clause :

"WHERE u.user_type = 2 AND u.status != 3 /'{$where}/'" ,


wordpress error :

Severity: error --> Exception: Call to undefined function curl_init() I think your hosting comment out curl on php.ini Where can i edit php.ini file? I want to remove the ; mark from the beginning of the following line: ;extension=php_curl.dll