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<?php | |
/* | |
* Helper functions for building a DataTables server-side processing SQL query | |
* | |
* The static functions in this class are just helper functions to help build | |
* the SQL used in the DataTables demo server-side processing scripts. These | |
* functions obviously do not represent all that can be done with server-side | |
* processing, they are intentionally simple to show how it works. More complex | |
* server-side processing operations will likely require a custom script. | |
* | |
* See http://datatables.net/usage/server-side for full details on the server- | |
* side processing requirements of DataTables. | |
* | |
* @license MIT - http://datatables.net/license_mit | |
*/ | |
// REMOVE THIS BLOCK - used for DataTables test environment only! | |
/* | |
$file = $_SERVER['DOCUMENT_ROOT'].'/datatables/mysql.php'; | |
if ( is_file( $file ) ) { | |
include( $file ); | |
} | |
*/ | |
class SSP { | |
/** | |
* Create the data output array for the DataTables rows | |
* | |
* @param array $columns Column information array | |
* @param array $data Data from the SQL get | |
* @return array Formatted data in a row based format | |
*/ | |
static function data_output ( $columns, $data ) | |
{ | |
$out = array(); | |
for ( $i=0, $ien=count($data) ; $i<$ien ; $i++ ) { | |
$row = array(); | |
for ( $j=0, $jen=count($columns) ; $j<$jen ; $j++ ) { | |
$column = $columns[$j]; | |
// Is there a formatter? | |
if ( isset( $column['formatter'] ) ) { | |
$row[ $column['dt'] ] = $column['formatter']( $data[$i][ $column['db'] ], $data[$i] ); | |
} | |
else { | |
$row[ $column['dt'] ] = $data[$i][ $columns[$j]['db'] ]; | |
} | |
} | |
$out[] = $row; | |
} | |
return $out; | |
} | |
/** | |
* Paging | |
* | |
* Construct the LIMIT clause for server-side processing SQL query | |
* | |
* @param array $request Data sent to server by DataTables | |
* @param array $columns Column information array | |
* @return string SQL limit clause | |
*/ | |
static function limit ( $request, $columns ) | |
{ | |
$limit = ''; | |
if ( isset($request['start']) && $request['length'] != -1 ) { | |
$limit = "OFFSET ".intval($request['start'])." LIMIT ".intval($request['length']); | |
} | |
return $limit; | |
} | |
/** | |
* Ordering | |
* | |
* Construct the ORDER BY clause for server-side processing SQL query | |
* | |
* @param array $request Data sent to server by DataTables | |
* @param array $columns Column information array | |
* @return string SQL order by clause | |
*/ | |
static function order ( $request, $columns ) | |
{ | |
$order = ''; | |
if ( isset($request['order']) && count($request['order']) ) { | |
$orderBy = array(); | |
$dtColumns = SSP::pluck( $columns, 'dt' ); | |
for ( $i=0, $ien=count($request['order']) ; $i<$ien ; $i++ ) { | |
// Convert the column index into the column data property | |
$columnIdx = intval($request['order'][$i]['column']); | |
$requestColumn = $request['columns'][$columnIdx]; | |
$columnIdx = array_search( $requestColumn['data'], $dtColumns ); | |
$column = $columns[ $columnIdx ]; | |
if ( $requestColumn['orderable'] == 'true' ) { | |
$dir = $request['order'][$i]['dir'] === 'asc' ? | |
'ASC' : | |
'DESC'; | |
$orderBy[] = ''.$column['db'].' '.$dir; | |
} | |
} | |
$order = 'ORDER BY '.implode(', ', $orderBy); | |
} | |
return $order; | |
} | |
/** | |
* Searching / Filtering | |
* | |
* Construct the WHERE clause for server-side processing SQL query. | |
* | |
* NOTE this does not match the built-in DataTables filtering which does it | |
* word by word on any field. It's possible to do here performance on large | |
* databases would be very poor | |
* | |
* @param array $request Data sent to server by DataTables | |
* @param array $columns Column information array | |
* @param array $bindings Array of values for PDO bindings, used in the | |
* sql_exec() function | |
* @return string SQL where clause | |
*/ | |
static function filter ( $request, $columns, &$bindings ) | |
{ | |
$globalSearch = array(); | |
$columnSearch = array(); | |
$dtColumns = SSP::pluck( $columns, 'dt' ); | |
if ( isset($request['search']) && $request['search']['value'] != '' ) { | |
$str = $request['search']['value']; | |
for ( $i=0, $ien=count($request['columns']) ; $i<$ien ; $i++ ) { | |
$requestColumn = $request['columns'][$i]; | |
$columnIdx = array_search( $requestColumn['data'], $dtColumns ); | |
$column = $columns[ $columnIdx ]; | |
if ( $requestColumn['searchable'] == 'true' ) { | |
$binding = SSP::bind( $bindings, '%'.$str.'%', PDO::PARAM_STR ); | |
$globalSearch[] = "text(".$column['db'].") LIKE ".$binding; | |
} | |
} | |
} | |
// Individual column filtering | |
for ( $i=0, $ien=count($request['columns']) ; $i<$ien ; $i++ ) { | |
$requestColumn = $request['columns'][$i]; | |
$columnIdx = array_search( $requestColumn['data'], $dtColumns ); | |
$column = $columns[ $columnIdx ]; | |
$str = $requestColumn['search']['value']; | |
if ( $requestColumn['searchable'] == 'true' && | |
$str != '' ) { | |
$binding = SSP::bind( $bindings, '%'.$str.'%', PDO::PARAM_STR ); | |
$columnSearch[] = "text(".$column['db'].") LIKE ".$binding; | |
} | |
} | |
// Combine the filters into a single string | |
$where = ''; | |
if ( count( $globalSearch ) ) { | |
$where = '('.implode(' OR ', $globalSearch).')'; | |
} | |
if ( count( $columnSearch ) ) { | |
$where = $where === '' ? | |
implode(' AND ', $columnSearch) : | |
$where .' AND '. implode(' AND ', $columnSearch); | |
} | |
if ( $where !== '' ) { | |
$where = 'WHERE '.$where; | |
} | |
return $where; | |
} | |
/** | |
* Perform the SQL queries needed for an server-side processing requested, | |
* utilising the helper functions of this class, limit(), order() and | |
* filter() among others. The returned array is ready to be encoded as JSON | |
* in response to an SSP request, or can be modified if needed before | |
* sending back to the client. | |
* | |
* @param array $request Data sent to server by DataTables | |
* @param array $sql_details SQL connection details - see sql_connect() | |
* @param string $table SQL table to query | |
* @param string $primaryKey Primary key of the table | |
* @param array $columns Column information array | |
* @return array Server-side processing response array | |
*/ | |
static function simple ( $request, $sql_details, $table, $primaryKey, $columns ) | |
{ | |
$bindings = array(); | |
$db = SSP::sql_connect( $sql_details ); | |
// Build the SQL query string from the request | |
$limit = SSP::limit( $request, $columns ); | |
$order = SSP::order( $request, $columns ); | |
$where = SSP::filter( $request, $columns, $bindings ); | |
// Main query to actually get the data | |
$psql = "SELECT ".implode(", ", SSP::pluck($columns, 'db')).", count(*) OVER() AS total_count | |
FROM $table | |
$where | |
$order | |
$limit"; | |
$data = SSP::sql_exec( $db, $bindings,$psql); | |
// Data set length after filtering | |
$recordsFiltered = $data[0]["total_count"]; | |
// Total data set length | |
$resTotalLength = SSP::sql_exec( $db, | |
"SELECT COUNT({$primaryKey}) | |
FROM $table" | |
); | |
$recordsTotal = $resTotalLength[0][0]; | |
/* | |
* Output | |
*/ | |
return array( | |
"draw" => intval( $request['draw'] ), | |
"recordsTotal" => intval( $recordsTotal ), | |
"recordsFiltered" => intval( $recordsFiltered ), | |
"data" => SSP::data_output( $columns, $data ), | |
"sql" => $psql | |
); | |
} | |
/** | |
* Connect to the database | |
* | |
* @param array $sql_details SQL server connection details array, with the | |
* properties: | |
* * host - host name | |
* * db - database name | |
* * user - user name | |
* * pass - user password | |
* @return resource Database connection handle | |
*/ | |
static function sql_connect ( $sql_details ) | |
{ | |
try { | |
$db = @new PDO( | |
"pgsql:host={$sql_details['host']};dbname={$sql_details['db']}", | |
$sql_details['user'], | |
$sql_details['pass'], | |
array( PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION ) | |
); | |
} | |
catch (PDOException $e) { | |
SSP::fatal( | |
"An error occurred while connecting to the database. ". | |
"The error reported by the server was: ".$e->getMessage() | |
); | |
} | |
return $db; | |
} | |
/** | |
* Execute an SQL query on the database | |
* | |
* @param resource $db Database handler | |
* @param array $bindings Array of PDO binding values from bind() to be | |
* used for safely escaping strings. Note that this can be given as the | |
* SQL query string if no bindings are required. | |
* @param string $sql SQL query to execute. | |
* @return array Result from the query (all rows) | |
*/ | |
static function sql_exec ( $db, $bindings, $sql=null ) | |
{ | |
// Argument shifting | |
if ( $sql === null ) { | |
$sql = $bindings; | |
} | |
$stmt = $db->prepare( $sql ); | |
//echo $sql; | |
// Bind parameters | |
if ( is_array( $bindings ) ) { | |
for ( $i=0, $ien=count($bindings) ; $i<$ien ; $i++ ) { | |
$binding = $bindings[$i]; | |
$stmt->bindValue( $binding['key'], $binding['val'], $binding['type'] ); | |
} | |
} | |
// Execute | |
try { | |
$stmt->execute(); | |
} | |
catch (PDOException $e) { | |
SSP::fatal( "An SQL error occurred: ".$e->getMessage()." [with] '".$sql."'" ); | |
} | |
// Return all | |
return $stmt->fetchAll(); | |
} | |
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * | |
* Internal methods | |
*/ | |
/** | |
* Throw a fatal error. | |
* | |
* This writes out an error message in a JSON string which DataTables will | |
* see and show to the user in the browser. | |
* | |
* @param string $msg Message to send to the client | |
*/ | |
static function fatal ( $msg ) | |
{ | |
echo json_encode( array( | |
"error" => $msg | |
) ); | |
exit(0); | |
} | |
/** | |
* Create a PDO binding key which can be used for escaping variables safely | |
* when executing a query with sql_exec() | |
* | |
* @param array &$a Array of bindings | |
* @param * $val Value to bind | |
* @param int $type PDO field type | |
* @return string Bound key to be used in the SQL where this parameter | |
* would be used. | |
*/ | |
static function bind ( &$a, $val, $type ) | |
{ | |
$key = ':binding_'.count( $a ); | |
$a[] = array( | |
'key' => $key, | |
'val' => $val, | |
'type' => $type | |
); | |
return $key; | |
} | |
/** | |
* Pull a particular property from each assoc. array in a numeric array, | |
* returning and array of the property values from each item. | |
* | |
* @param array $a Array to get data from | |
* @param string $prop Property to read | |
* @return array Array of property values | |
*/ | |
static function pluck ( $a, $prop ) | |
{ | |
$out = array(); | |
for ( $i=0, $len=count($a) ; $i<$len ; $i++ ) { | |
$out[] = $a[$i][$prop]; | |
} | |
return $out; | |
} | |
} | |
?> |
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