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Developing with Couchbase Part III:

The Client LibrariesJohn ZablockiDeveloper Advocate

@codevoyeur

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The View API

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Preamble

All examples are in PHP using the Couchbase PHP SDK 1.1

Download at couchbase.com/develop/php/next

Here's how to connect to Couchbase Server:

<?php// Setup Couchbase connected objectstry { $cb = new Couchbase("127.0.0.1:8091", "", "", "beer-sample");} catch (ErrorException $e) { die($e->getMessage());}// $cb will be used throughout to reference the Couchbase object

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A Beer Document

{"_id": "brewery_cottrell_brewing","_rev": "1-00003e56c0e830c80000005900000112","type": "brewery","name": "Cottrell Brewing","city": "Pawcatuck","province": "Connecticut"

}

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Querying with PHP – Custom View

_design/beer/_view/names

// map functionfunction(doc) { if(doc.name) { emit(doc.name, 1); }}

via PHP

$result = $cb->view(“beers“, “by_name”); // "custom" viewforeach($result AS $row) { echo $row->key . ": " . $row->value;}

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Querying with PHP – Custom View Reverse

Flip it withdescending = true

// PHP Code

$result= $cb->view(“beers“, “by_name?descending=true");

foreach($result AS $row) { echo $row->key . ": " $row->value;}

CAUTION: it's not always what you think

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Querying with PHP – Custom View Key

// PHP Code

$result= $cb->view("beer”, “by_name?=‘Hoptimus Prime’”);

foreach($result AS $row) { echo $row->key . ": " $row->value;}

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Querying with PHP – Custom View Key Range

// PHP Code

$result= $cb->view(“beers“, “by_name?startkey=‘A’&endkey=‘B’”);

foreach($result AS $row) { echo $row->key . ": " $row->value;}

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Querying with PHP – Custom View Key Range Limit

// PHP Code

$view = $cb->getView("beer/names");$result = $view->query(array( "startkey" => "A", "endkey" => "B", "limit" => 10));

foreach($result AS $row) { echo $row->key . ": " $row->value;}

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Using the query api for calculation

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Querying with PHP – Custom View

_design/beer/_view/categories

// map functionfunction(doc) { if(doc.category) { emit(doc.category, 1); }}// reduce: _count

via PHP

$view = $cb->getView("beer/categories");$result = $view->query(array( "group" => true));

foreach($result AS $row) { echo $row->key . ": " $row->value;}

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View Calculation Result

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Paging over views

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Querying with PHP – Custom View Pagination

<?php

$view = $cb->getView("beer/names");

$resultPages = $view->getResultPaginator();$resultPages->setRowsPerPage(10);$resultPages->setOptions(array( "startkey" => "A", "endkey" => "B");foreach($resultPages AS $row) { echo $row->key . ": " $row->value;}

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Querying with PHP – Custom View Pagination

<?php

$view = $cb->getView("beer/names");

$pageKey = $_GET["pageKey"]; // URL ESCAPE!

$resultPages = $view->getResultPaginator();$resultPages->setPageKey($pageKey);$resultPages->setRowsPerPage(10);$resultPages->setOptions(array( "startkey" => "A", "endkey" => "B");foreach($resultPages AS $row) { echo $row->key . ": " $row->value;}

$pageKey = $resultPages->key();echo '<a href='"?pageKey=' . $pageKey. '"'>Next</a>';

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Error handling

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Error Handling

<?php// ... skip setup

$cb->set("a", 1); // Silent Oops.

$result = $cb->set("a", 1);if($result == false) { $code = $cb->getResultCode(); echo $cb->getResultMessage($code);}

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Error Handling

<?php// ... skip setup

$result = $cb->set("a", 1);if($result == false) { // something went wrong $code = $cb->getResultCode(); // lets find itswitch($code) { case COUCHBASE::RES_HOST_LOOKUP_FAILURE: echo "DNS lookup to Server failed"; break; case COUCHBASE::RES_UNKNOWN_READ_FAILURE: echo "Failed to read from network"; break; case COUCHBASE::RES_WRITE_FAILURE: echo "Failed to read from network"; break; case COUCHBASE:RES_TIMEOUT: echo "Operation timed out"; break;}}

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• Would be great if everything went perfectly in a cluster, but…– Node failures– System becomes overloaded– Temporary out of memory conditions

Cluster Ready Error Handling

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Q&A