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<?php |
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|
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/** |
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* This file contains the ProxyDataSource child class |
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* that uses the Data::Driver::Proxy object to talk to a remote rpc server. |
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* |
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* Data::Driver::Proxy uses a PEAR XML::RPC object to actually |
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* talk HTTP and serialize data chunks to and from XML, |
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* but adds some caching to this "process of fetching data from a remote side". |
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* It "proxies" arbitrary data chunks a) inside a native php4 session, |
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* b) by talking to a rdbms (single proxy-table) or c) [TODO] using PEAR::Cache. |
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* |
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* @author Andreas Motl <andreas.motl@ilo.de> |
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* @author Sebastian Utz <seut@tunemedia.de> |
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* @package phpHtmlLib |
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*/ |
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|
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/** |
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* $Id: ProxyDataSource.inc,v 1.1 2003/03/01 03:10:40 joko Exp $ |
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* |
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* $Log: ProxyDataSource.inc,v $ |
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* Revision 1.1 2003/03/01 03:10:40 joko |
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* + initial commit |
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* |
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* |
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*/ |
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|
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/** |
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* This requires the MemoryDataSource base class |
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* |
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*/ |
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include_once($phphtmllib."/widgets/data_source/MemoryDataSource.inc"); |
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|
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/** |
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* Have to have PEAR and DB included |
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* the pear dir must be in the |
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* include path. |
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*/ |
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//require_once("PEAR.php"); // FIXME: what about PEAR::XML::RPC? |
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//require_once("DB.php"); |
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|
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/** |
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* This ProxyDataSource child class is *completely* independent |
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* of a specific storage implementation and intended to be a wrapper |
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* class on the way from phpHtmlLib to Xyz. |
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* ("Yyz" gets represented by Data::Storage by now.....) |
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* |
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* ProxyDataSource interacts with an intermediate "proxy" object |
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* (e.g. Data::Driver::Proxy) when doing queries. |
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* Don't mix this up with a persistent database handle which gets |
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* reused each and every time for different queries. |
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* Here *is* a new instance of Data::Driver::Proxy for *each* query. |
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* |
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* But the point is: Caching! The actual *data* isn't read redundant! |
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* |
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* Data::Driver::Proxy instantiates "handlers" below itself |
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* which act as encapsulated workers to actually do the stuff to do. |
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* It can cache data for "disconnected mode" using the |
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* php PEAR DB abstraction objects. |
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* One worker already implemented is Data::Driver::RPC::Remote, which |
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* talks to a RPC::XML server (todo: talk SOAP!) using PEAR::XML::RPC. |
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* |
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* How to use? |
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* |
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* Pass an array holding "locator metadata" to the constructor. |
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* ProxyDataSource takes care of the rest. |
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* |
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* Pass an array to the constructor: (e.g.) |
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* |
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* 1. doing rpc-calls.... |
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* $locator = array( |
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* type => 'rpc', |
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* metadata => array( Host => 'localhost', Port => '8765' ), |
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* ); |
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* $source = new ProxyDataSource($locator); |
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* $this->set_data_source( &$source ); |
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* |
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* 2. [proposal] common datahandles.... |
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* $locator = array( |
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* type => 'mysql', |
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* dsn => 'known dsn markup', |
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* ); |
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* $source = new ProxyDataSource($locator); |
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* $this->set_data_source( &$source ); |
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* |
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* @author Andreas Motl <andreas.motl@ilo.de> |
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* @author Sebastian Utz <seut@tunemedia.de> |
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* @package phpHtmlLib |
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*/ |
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|
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/** |
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* Todo: |
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* |
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* o mungle this to be able to be wrapped around phpHtmlLib's own storage-handles |
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* o implement another Data::Driver::Proxy container |
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* |
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*/ |
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|
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|
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class ProxyDataSource extends MemoryDataSource { |
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|
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/** |
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* This var holds the locator metadata hash |
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* that is used to feed metadata to a per-query-instance |
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* of a Data::Driver::Proxy object. |
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*/ |
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var $_locator = NULL; |
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|
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/** |
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* This var holds the query hash |
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* that is used to feed as query to a per-query-instance |
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* of a Data::Driver::Proxy object. |
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*/ |
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var $_query = NULL; |
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|
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|
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/** |
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* This var holds the Proxy object |
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* that is used to do the work. |
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* It acts as a dispatcher combining result caching. |
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* It is assumed that this provides 4 methods: |
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* queryData() - execute a query against a data storage |
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* querySchema() - execute a query against underlying storage metadata |
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* sendCommand() - send a command against an arbitrary execution engine |
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*/ |
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var $_proxy = NULL; |
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|
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/** |
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* this holds the query result from the |
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* Data::Driver::Proxy->queryXyz() call |
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* |
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*/ |
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var $_result = NULL; |
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|
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|
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/** |
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* The constructor is used to pass in the |
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* locator metadata hash. |
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* |
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* @param LocatorMetadataHash array - layout: array( type => '', metadata => '', dsn => '' ) |
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* @param Query array - layout: array( type => '', metadata => '', dsn => '' ) |
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*/ |
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function ProxyDataSource( &$locator, $query ) { |
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|
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$this->trace = 0; |
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|
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$this->set_locator( $locator ); |
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$this->set_query( $query ); |
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} |
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|
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/** |
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* Set the locator metadata hash we will feed *partly* |
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* to an encapsulated Data::Driver::Proxy instance. |
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* |
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* @param LocatorMetadataHash array - |
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* |
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*/ |
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function set_locator( &$locator ) { |
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$this->_locator = &$locator; |
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} |
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|
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/** |
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* Set the query metadata hash we will feed *completely* |
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* to an encapsulated Data::Driver::Proxy instance. |
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* |
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* @param QueryDeclaration array - |
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* |
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*/ |
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function set_query( $query ) { |
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$this->_query = $query; |
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} |
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|
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/** |
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* Directly inject a Data::Driver::Proxy instance to use. |
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* |
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* @param Data::Driver::Proxy object - &$proxy |
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* |
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*/ |
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function set_proxy( &$proxy ) { |
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$this->_proxy = &$proxy; |
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} |
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|
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/** |
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* Issue remote/proxy call |
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* Stolen from Application_AbstractBackend::_remote_method (RefactoringProposal?) |
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* Tweaked a bit: proxy package now taken from $this->_proxy_name |
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* |
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* Create a new instance of a proxy and store it for later reuse. |
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* Read the locator metadata hash and create |
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* the proxy handler instance using passed-in name. |
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* |
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* @param string - $proxy_name (namespaced classname - perl syntax - e.g.: Data::Driver::Proxy) |
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* |
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*/ |
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function call_proxy_method() { |
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|
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|
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// 1. read args |
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|
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$arg_list = func_get_args(); |
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$command = array_shift($arg_list); |
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$cache_key = join("-", array(session_id(), $command, join('_', $arg_list) )); |
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//print "cache_key: $cache_key<br>"; |
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|
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// FIXME: what if arg_list still contains more elements after doing this? |
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$query = array_shift($arg_list); |
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|
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|
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// 2. prepare proxy-options |
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|
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// read from locator metadata |
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$proxy_name = $this->_locator[metadata][package]; |
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$rpcinfo = array( Host => $this->_locator[metadata][Host], Port => $this->_locator[metadata][Port] ); |
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|
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// FIXME! implement this into Data::Driver::RPC::Remote! |
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//$rpcinfo[to_latin] = 1; |
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|
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// FIXME! patch query |
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if (sizeof($query) == 1) { |
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$query = $query[0]; |
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} |
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|
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// -------------------- clone this & modify ---------- |
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$proxy = mkObject($proxy_name, $cache_key, array( key => 1, command => $command, query => $query, remote => 1, rpcinfo => $rpcinfo, cache => array( db => 0, session => 1 ) ) ); |
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$this->set_proxy( $proxy ); |
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//$result = $resultHandle->getAttributes(); |
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//return $result; |
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//$this->_result = $resultHandle->getAttributes(); |
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//$this->_result = $this->_proxy->getAttributes(); |
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// -------------------- clone this & modify ---------- |
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|
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} |
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|
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function O_do_query() { |
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$this->_result = $this->_db->query($this->_query); |
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if (DB::isError($this->_result)) { |
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$msg = $this->_result->getMessage(); |
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user_error("PEARSQLDataListSource::do_query() - query failed : ".$msg); |
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} |
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} |
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|
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function call_proxy() { |
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|
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// make up a command from metadata |
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// FIXME: abstract this some more (e.g. via a CommandMapper|Registry) |
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switch ($this->_query[metatype]) { |
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case 'data': |
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//$command = 'queryData'; |
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$command = 'getObjects'; // FIXME!!! |
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$args = array(); |
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switch ($this->_query[vartype]) { |
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case 'object': |
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if (!$this->_query[classname]) { |
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$msg = "_query[vartype] == 'object' requires _query[classname]"; |
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user_error("ProxyDataSource::do_query() - failed: " . $msg); |
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} |
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array_push($args, $this->_query[classname]); |
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break; |
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} |
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break; |
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case 'schema': |
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$command = 'querySchema'; |
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break; |
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} |
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|
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// trace |
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if ($this->trace) { |
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print "ProxyDataSource->do_query()<br/>"; |
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print "_locator = " . Dumper($this->_locator); |
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print "_query = " . Dumper($this->_query); |
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print "<b>\$command = " . $command . "</b><br/>"; |
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print "<b>\$args = " . Dumper($args) . "</b><br/>"; |
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} |
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|
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// pre-flight checks |
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if (!$command) { |
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$msg = "Remote command could not be resolved, please pass in or check configuration."; |
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user_error("ProxyDataSource::do_query() - failed: " . $msg); |
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return; |
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} |
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|
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// do remote call here and get result |
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// FIXME: handle synchronous/asynchronous mode here!!! |
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$this->call_proxy_method($command, $args); |
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// TODO: ... = $this->poll_proxy_result and $this->get_proxy_result |
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$this->_result = $this->_proxy->getAttributes(); |
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|
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// trace |
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if ($this->trace) { |
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//print "_result = " . Dumper($this->_result); |
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print "_result - count = " . sizeof($this->_result) . "<br/>"; |
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} |
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|
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// pass data to MemoryDataSource |
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|
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// V1 - doesn't work! |
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//$this->_data_list = $this->_result; |
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|
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// V2 - ??? |
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//$this->MemoryDataSource(); |
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|
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// V3 - copy & paste |
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/* |
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foreach ($this->_result as $value) { |
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print Dumper($value); |
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if ($this->add_data_row($value)) { |
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$count++; |
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} |
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} |
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$this->set_total_rows( $count ); |
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$this->sort(); |
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*/ |
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|
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} |
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|
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|
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|
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function O_do_prequery() { |
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//print "prequery!<br/>"; |
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// HACK!!! |
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// modify behaviour here: for now it is needed to call for the schem |
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// eventually modify here to get schema from some registry component (already locally available) |
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$this->call_proxy(); |
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//print Dumper($this->_result); |
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//print Dumper($this->_result[0]); |
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//exit; |
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|
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//$this->_get_header(); |
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} |
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|
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function do_query() { |
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//print "query!<br/>"; |
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$this->handle_result(); |
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} |
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|
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function _get_header() { |
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//$this->do_prequery(); |
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// FIXME: prevent multi-calls by base class |
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$this->call_proxy(); |
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foreach($this->_result[0] as $key => $value) { |
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array_push($this->_data_keys, $key); |
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} |
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|
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$this->set_schema($this->_result[0]); |
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|
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//$this->_get_header(); |
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//return $this->_data_keys; |
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|
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} |
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|
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|
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/** |
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* This function gets the next data row |
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* from the query() |
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* |
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* @return array() |
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*/ |
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function O_get_next_data_row() { |
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return $this->_result->fetchRow(DB_FETCHMODE_ASSOC); |
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} |
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|
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/** |
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* This function builds the limit |
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* clause portion of a DB query. |
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* |
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* @return string - the limit portion of |
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* the query. |
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*/ |
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function O_build_limit_clause($offset, $limit) { |
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if ($this->get_limit() != -1 ) { |
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if ($offset == '' || $offset == "none") { |
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$offset = 0; |
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} |
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switch(get_class($this->_db)) { |
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case "db_mysql": |
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$clause = " LIMIT $offset, $limit "; |
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break; |
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case "db_pgsql": |
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$clause = " LIMIT $limit, $offset "; |
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break; |
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default: |
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$clause = " LIMIT $offset, $limit "; |
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break; |
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} |
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return $clause; |
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} else { |
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return NULL; |
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} |
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} |
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|
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/** |
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* find the number of rows to be returned |
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* from a query from a table and where clause |
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* |
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* @param string $table - the table to count from |
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* @param string $where_clause - a where clause |
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* |
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* @return int the # of rows |
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*/ |
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function O_count($tables, $where_clause='', $count_clause='*') { |
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$query = "select count(".$count_clause.") as COUNT from ".$tables." ".$where_clause; |
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$result = $this->_db->query($query); |
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if (DB::isError($this->_result)) { |
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$msg = $result->getMessage(); |
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user_error("PEARSQLDataListSource::count() - query failed : ".$msg); |
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} |
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$value = $result->fetchRow(DB_FETCHMODE_ASSOC); |
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return ($value ? (int)$value["COUNT"] : NULL); |
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} |
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|
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} |
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|
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?> |
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