1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
|
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>
examples.dogpile_caching.relationship_caching
—
SQLAlchemy 0.9 Documentation
</title>
<!-- begin iterate through SQLA + sphinx environment css_files -->
<link rel="stylesheet" href="../../../_static/pygments.css" type="text/css" />
<link rel="stylesheet" href="../../../_static/docs.css" type="text/css" />
<link rel="stylesheet" href="../../../_static/sphinx_paramlinks.css" type="text/css" />
<link rel="stylesheet" href="../../../_static/changelog.css" type="text/css" />
<!-- end iterate through SQLA + sphinx environment css_files -->
<!-- begin layout.mako headers -->
<script type="text/javascript">
var DOCUMENTATION_OPTIONS = {
URL_ROOT: '../../../',
VERSION: '0.9.8',
COLLAPSE_MODINDEX: false,
FILE_SUFFIX: '.html'
};
</script>
<!-- begin iterate through sphinx environment script_files -->
<script type="text/javascript" src="../../../_static/jquery.js"></script>
<script type="text/javascript" src="../../../_static/underscore.js"></script>
<script type="text/javascript" src="../../../_static/doctools.js"></script>
<!-- end iterate through sphinx environment script_files -->
<script type="text/javascript" src="../../../_static/detectmobile.js"></script>
<script type="text/javascript" src="../../../_static/init.js"></script>
<link rel="index" title="Index" href="../../../genindex.html" />
<link rel="search" title="Search" href="../../../search.html" />
<link rel="copyright" title="Copyright" href="../../../copyright.html" />
<link rel="top" title="SQLAlchemy 0.9 Documentation" href="../../../index.html" />
<link rel="up" title="Module code" href="../../index.html" />
<!-- end layout.mako headers -->
</head>
<body>
<div id="docs-container">
<div id="docs-top-navigation-container" class="body-background">
<div id="docs-header">
<div id="docs-version-header">
Release: <span class="version-num">0.9.8</span> | Release Date: October 13, 2014
</div>
<h1>SQLAlchemy 0.9 Documentation</h1>
</div>
</div>
<div id="docs-body-container">
<div id="fixed-sidebar" class="">
<div id="index-nav">
<form class="search" action="../../../search.html" method="get">
<input type="text" name="q" size="12" /> <input type="submit" value="Search" />
<input type="hidden" name="check_keywords" value="yes" />
<input type="hidden" name="area" value="default" />
</form>
<p>
<a href="../../../index.html">Contents</a> |
<a href="../../../genindex.html">Index</a>
</p>
</div>
</div>
<div id="docs-body" class="" >
<h1>Source code for examples.dogpile_caching.relationship_caching</h1><div class="highlight"><pre>
<span class="sd">"""relationship_caching.py</span>
<span class="sd">Illustrates how to add cache options on</span>
<span class="sd">relationship endpoints, so that lazyloads load from cache.</span>
<span class="sd">Load a set of Person and Address objects, specifying that</span>
<span class="sd">related PostalCode, City, Country objects should be pulled from long</span>
<span class="sd">term cache.</span>
<span class="sd">"""</span>
<span class="kn">from</span> <span class="nn">.environment</span> <span class="kn">import</span> <span class="n">Session</span><span class="p">,</span> <span class="n">root</span>
<span class="kn">from</span> <span class="nn">.model</span> <span class="kn">import</span> <span class="n">Person</span><span class="p">,</span> <span class="n">cache_address_bits</span>
<span class="kn">from</span> <span class="nn">sqlalchemy.orm</span> <span class="kn">import</span> <span class="n">joinedload</span>
<span class="kn">import</span> <span class="nn">os</span>
<span class="k">for</span> <span class="n">p</span> <span class="ow">in</span> <span class="n">Session</span><span class="o">.</span><span class="n">query</span><span class="p">(</span><span class="n">Person</span><span class="p">)</span><span class="o">.</span><span class="n">options</span><span class="p">(</span><span class="n">joinedload</span><span class="p">(</span><span class="n">Person</span><span class="o">.</span><span class="n">addresses</span><span class="p">),</span> <span class="n">cache_address_bits</span><span class="p">):</span>
<span class="k">print</span><span class="p">(</span><span class="n">p</span><span class="o">.</span><span class="n">format_full</span><span class="p">())</span>
<span class="k">print</span><span class="p">(</span><span class="s">"</span><span class="se">\n\n</span><span class="s">If this was the first run of relationship_caching.py, SQL was likely emitted to "</span>\
<span class="s">"load postal codes, cities, countries.</span><span class="se">\n</span><span class="s">"</span>\
<span class="s">"If run a second time, assuming the cache is still valid, "</span>\
<span class="s">"only a single SQL statement will run - all "</span>\
<span class="s">"related data is pulled from cache.</span><span class="se">\n</span><span class="s">"</span>\
<span class="s">"To clear the cache, delete the file </span><span class="si">%r</span><span class="s">. </span><span class="se">\n</span><span class="s">"</span>\
<span class="s">"This will cause a re-load of cities, postal codes and countries on "</span>\
<span class="s">"the next run.</span><span class="se">\n</span><span class="s">"</span>\
<span class="o">%</span> <span class="n">os</span><span class="o">.</span><span class="n">path</span><span class="o">.</span><span class="n">join</span><span class="p">(</span><span class="n">root</span><span class="p">,</span> <span class="s">'cache.dbm'</span><span class="p">))</span></pre></div>
</div>
</div>
<div id="docs-bottom-navigation" class="docs-navigation-links">
<div id="docs-copyright">
© <a href="../../../copyright.html">Copyright</a> 2007-2014, the SQLAlchemy authors and contributors.
Created using <a href="http://sphinx.pocoo.org/">Sphinx</a> 1.2b1.
</div>
</div>
</div>
</body>
</html>
|
