| <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> |
| <html> |
| <head> |
| <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> |
| <title>Relations and Tuples</title> |
| <meta name="generator" content="DocBook XSL Stylesheets V1.75.2"> |
| <link rel="home" href="index.html" title="GLib Reference Manual"> |
| <link rel="up" href="glib-data-types.html" title="GLib Data Types"> |
| <link rel="prev" href="glib-Datasets.html" title="Datasets"> |
| <link rel="next" href="glib-Caches.html" title="Caches"> |
| <meta name="generator" content="GTK-Doc V1.14 (XML mode)"> |
| <link rel="stylesheet" href="style.css" type="text/css"> |
| </head> |
| <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> |
| <table class="navigation" id="top" width="100%" summary="Navigation header" cellpadding="2" cellspacing="2"> |
| <tr valign="middle"> |
| <td><a accesskey="p" href="glib-Datasets.html"><img src="left.png" width="24" height="24" border="0" alt="Prev"></a></td> |
| <td><a accesskey="u" href="glib-data-types.html"><img src="up.png" width="24" height="24" border="0" alt="Up"></a></td> |
| <td><a accesskey="h" href="index.html"><img src="home.png" width="24" height="24" border="0" alt="Home"></a></td> |
| <th width="100%" align="center">GLib Reference Manual</th> |
| <td><a accesskey="n" href="glib-Caches.html"><img src="right.png" width="24" height="24" border="0" alt="Next"></a></td> |
| </tr> |
| <tr><td colspan="5" class="shortcuts"> |
| <a href="#glib-Relations-and-Tuples.synopsis" class="shortcut">Top</a> |
| | |
| <a href="#glib-Relations-and-Tuples.description" class="shortcut">Description</a> |
| </td></tr> |
| </table> |
| <div class="refentry" title="Relations and Tuples"> |
| <a name="glib-Relations-and-Tuples"></a><div class="titlepage"></div> |
| <div class="refnamediv"><table width="100%"><tr> |
| <td valign="top"> |
| <h2><span class="refentrytitle"><a name="glib-Relations-and-Tuples.top_of_page"></a>Relations and Tuples</span></h2> |
| <p>Relations and Tuples — tables of data which can be indexed on any |
| number of fields</p> |
| </td> |
| <td valign="top" align="right"></td> |
| </tr></table></div> |
| <div class="refsynopsisdiv" title="Synopsis"> |
| <a name="glib-Relations-and-Tuples.synopsis"></a><h2>Synopsis</h2> |
| <pre class="synopsis"> |
| #include <glib.h> |
| |
| <a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation">GRelation</a>; |
| <a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="returnvalue">GRelation</span></a>* <a class="link" href="glib-Relations-and-Tuples.html#g-relation-new" title="g_relation_new ()">g_relation_new</a> (<em class="parameter"><code><a class="link" href="glib-Basic-Types.html#gint" title="gint"><span class="type">gint</span></a> fields</code></em>); |
| <span class="returnvalue">void</span> <a class="link" href="glib-Relations-and-Tuples.html#g-relation-index" title="g_relation_index ()">g_relation_index</a> (<em class="parameter"><code><a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a> *relation</code></em>, |
| <em class="parameter"><code><a class="link" href="glib-Basic-Types.html#gint" title="gint"><span class="type">gint</span></a> field</code></em>, |
| <em class="parameter"><code><a class="link" href="glib-Hash-Tables.html#GHashFunc" title="GHashFunc ()"><span class="type">GHashFunc</span></a> hash_func</code></em>, |
| <em class="parameter"><code><a class="link" href="glib-Hash-Tables.html#GEqualFunc" title="GEqualFunc ()"><span class="type">GEqualFunc</span></a> key_equal_func</code></em>); |
| <span class="returnvalue">void</span> <a class="link" href="glib-Relations-and-Tuples.html#g-relation-insert" title="g_relation_insert ()">g_relation_insert</a> (<em class="parameter"><code><a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a> *relation</code></em>, |
| <em class="parameter"><code>...</code></em>); |
| <a class="link" href="glib-Basic-Types.html#gboolean" title="gboolean"><span class="returnvalue">gboolean</span></a> <a class="link" href="glib-Relations-and-Tuples.html#g-relation-exists" title="g_relation_exists ()">g_relation_exists</a> (<em class="parameter"><code><a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a> *relation</code></em>, |
| <em class="parameter"><code>...</code></em>); |
| <a class="link" href="glib-Basic-Types.html#gint" title="gint"><span class="returnvalue">gint</span></a> <a class="link" href="glib-Relations-and-Tuples.html#g-relation-count" title="g_relation_count ()">g_relation_count</a> (<em class="parameter"><code><a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a> *relation</code></em>, |
| <em class="parameter"><code><a class="link" href="glib-Basic-Types.html#gconstpointer" title="gconstpointer"><span class="type">gconstpointer</span></a> key</code></em>, |
| <em class="parameter"><code><a class="link" href="glib-Basic-Types.html#gint" title="gint"><span class="type">gint</span></a> field</code></em>); |
| <a class="link" href="glib-Relations-and-Tuples.html#GTuples" title="GTuples"><span class="returnvalue">GTuples</span></a>* <a class="link" href="glib-Relations-and-Tuples.html#g-relation-select" title="g_relation_select ()">g_relation_select</a> (<em class="parameter"><code><a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a> *relation</code></em>, |
| <em class="parameter"><code><a class="link" href="glib-Basic-Types.html#gconstpointer" title="gconstpointer"><span class="type">gconstpointer</span></a> key</code></em>, |
| <em class="parameter"><code><a class="link" href="glib-Basic-Types.html#gint" title="gint"><span class="type">gint</span></a> field</code></em>); |
| <a class="link" href="glib-Basic-Types.html#gint" title="gint"><span class="returnvalue">gint</span></a> <a class="link" href="glib-Relations-and-Tuples.html#g-relation-delete" title="g_relation_delete ()">g_relation_delete</a> (<em class="parameter"><code><a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a> *relation</code></em>, |
| <em class="parameter"><code><a class="link" href="glib-Basic-Types.html#gconstpointer" title="gconstpointer"><span class="type">gconstpointer</span></a> key</code></em>, |
| <em class="parameter"><code><a class="link" href="glib-Basic-Types.html#gint" title="gint"><span class="type">gint</span></a> field</code></em>); |
| <span class="returnvalue">void</span> <a class="link" href="glib-Relations-and-Tuples.html#g-relation-destroy" title="g_relation_destroy ()">g_relation_destroy</a> (<em class="parameter"><code><a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a> *relation</code></em>); |
| |
| <span class="returnvalue">void</span> <a class="link" href="glib-Relations-and-Tuples.html#g-relation-print" title="g_relation_print ()">g_relation_print</a> (<em class="parameter"><code><a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a> *relation</code></em>); |
| |
| <a class="link" href="glib-Relations-and-Tuples.html#GTuples" title="GTuples">GTuples</a>; |
| <span class="returnvalue">void</span> <a class="link" href="glib-Relations-and-Tuples.html#g-tuples-destroy" title="g_tuples_destroy ()">g_tuples_destroy</a> (<em class="parameter"><code><a class="link" href="glib-Relations-and-Tuples.html#GTuples" title="GTuples"><span class="type">GTuples</span></a> *tuples</code></em>); |
| <a class="link" href="glib-Basic-Types.html#gpointer" title="gpointer"><span class="returnvalue">gpointer</span></a> <a class="link" href="glib-Relations-and-Tuples.html#g-tuples-index" title="g_tuples_index ()">g_tuples_index</a> (<em class="parameter"><code><a class="link" href="glib-Relations-and-Tuples.html#GTuples" title="GTuples"><span class="type">GTuples</span></a> *tuples</code></em>, |
| <em class="parameter"><code><a class="link" href="glib-Basic-Types.html#gint" title="gint"><span class="type">gint</span></a> index_</code></em>, |
| <em class="parameter"><code><a class="link" href="glib-Basic-Types.html#gint" title="gint"><span class="type">gint</span></a> field</code></em>); |
| </pre> |
| </div> |
| <div class="refsect1" title="Description"> |
| <a name="glib-Relations-and-Tuples.description"></a><h2>Description</h2> |
| <p> |
| A <a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a> is a table of data which can be indexed on any number |
| of fields, rather like simple database tables. A <a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a> contains |
| a number of records, called tuples. Each record contains a number of |
| fields. Records are not ordered, so it is not possible to find the |
| record at a particular index. |
| </p> |
| <p> |
| Note that <a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a> tables are currently limited to 2 fields. |
| </p> |
| <p> |
| To create a GRelation, use <a class="link" href="glib-Relations-and-Tuples.html#g-relation-new" title="g_relation_new ()"><code class="function">g_relation_new()</code></a>. |
| </p> |
| <p> |
| To specify which fields should be indexed, use <a class="link" href="glib-Relations-and-Tuples.html#g-relation-index" title="g_relation_index ()"><code class="function">g_relation_index()</code></a>. |
| Note that this must be called before any tuples are added to the |
| <a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a>. |
| </p> |
| <p> |
| To add records to a <a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a> use <a class="link" href="glib-Relations-and-Tuples.html#g-relation-insert" title="g_relation_insert ()"><code class="function">g_relation_insert()</code></a>. |
| </p> |
| <p> |
| To determine if a given record appears in a <a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a>, use |
| <a class="link" href="glib-Relations-and-Tuples.html#g-relation-exists" title="g_relation_exists ()"><code class="function">g_relation_exists()</code></a>. Note that fields are compared directly, so |
| pointers must point to the exact same position (i.e. different |
| copies of the same string will not match.) |
| </p> |
| <p> |
| To count the number of records which have a particular value in a |
| given field, use <a class="link" href="glib-Relations-and-Tuples.html#g-relation-count" title="g_relation_count ()"><code class="function">g_relation_count()</code></a>. |
| </p> |
| <p> |
| To get all the records which have a particular value in a given |
| field, use <a class="link" href="glib-Relations-and-Tuples.html#g-relation-select" title="g_relation_select ()"><code class="function">g_relation_select()</code></a>. To access fields of the resulting |
| records, use <a class="link" href="glib-Relations-and-Tuples.html#g-tuples-index" title="g_tuples_index ()"><code class="function">g_tuples_index()</code></a>. To free the resulting records use |
| <a class="link" href="glib-Relations-and-Tuples.html#g-tuples-destroy" title="g_tuples_destroy ()"><code class="function">g_tuples_destroy()</code></a>. |
| </p> |
| <p> |
| To delete all records which have a particular value in a given |
| field, use <a class="link" href="glib-Relations-and-Tuples.html#g-relation-delete" title="g_relation_delete ()"><code class="function">g_relation_delete()</code></a>. |
| </p> |
| <p> |
| To destroy the <a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a>, use <a class="link" href="glib-Relations-and-Tuples.html#g-relation-destroy" title="g_relation_destroy ()"><code class="function">g_relation_destroy()</code></a>. |
| </p> |
| <p> |
| To help debug <a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a> objects, use <a class="link" href="glib-Relations-and-Tuples.html#g-relation-print" title="g_relation_print ()"><code class="function">g_relation_print()</code></a>. |
| </p> |
| </div> |
| <div class="refsect1" title="Details"> |
| <a name="glib-Relations-and-Tuples.details"></a><h2>Details</h2> |
| <div class="refsect2" title="GRelation"> |
| <a name="GRelation"></a><h3>GRelation</h3> |
| <pre class="programlisting">typedef struct _GRelation GRelation;</pre> |
| <p> |
| The <a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a> struct is an opaque data structure to represent a |
| <a class="link" href="glib-Relations-and-Tuples.html" title="Relations and Tuples">Relation</a>. It should |
| only be accessed via the following functions. |
| </p> |
| </div> |
| <hr> |
| <div class="refsect2" title="g_relation_new ()"> |
| <a name="g-relation-new"></a><h3>g_relation_new ()</h3> |
| <pre class="programlisting"><a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="returnvalue">GRelation</span></a>* g_relation_new (<em class="parameter"><code><a class="link" href="glib-Basic-Types.html#gint" title="gint"><span class="type">gint</span></a> fields</code></em>);</pre> |
| <p> |
| Creates a new <a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a> with the given number of fields. Note that |
| currently the number of fields must be 2. |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>fields</code></em> :</span></p></td> |
| <td>the number of fields. |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td>a new <a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a>. |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="g_relation_index ()"> |
| <a name="g-relation-index"></a><h3>g_relation_index ()</h3> |
| <pre class="programlisting"><span class="returnvalue">void</span> g_relation_index (<em class="parameter"><code><a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a> *relation</code></em>, |
| <em class="parameter"><code><a class="link" href="glib-Basic-Types.html#gint" title="gint"><span class="type">gint</span></a> field</code></em>, |
| <em class="parameter"><code><a class="link" href="glib-Hash-Tables.html#GHashFunc" title="GHashFunc ()"><span class="type">GHashFunc</span></a> hash_func</code></em>, |
| <em class="parameter"><code><a class="link" href="glib-Hash-Tables.html#GEqualFunc" title="GEqualFunc ()"><span class="type">GEqualFunc</span></a> key_equal_func</code></em>);</pre> |
| <p> |
| Creates an index on the given field. Note that this must be called |
| before any records are added to the <a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a>. |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>relation</code></em> :</span></p></td> |
| <td>a <a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a>. |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>field</code></em> :</span></p></td> |
| <td>the field to index, counting from 0. |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>hash_func</code></em> :</span></p></td> |
| <td>a function to produce a hash value from the field data. |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>key_equal_func</code></em> :</span></p></td> |
| <td>a function to compare two values of the given field. |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="g_relation_insert ()"> |
| <a name="g-relation-insert"></a><h3>g_relation_insert ()</h3> |
| <pre class="programlisting"><span class="returnvalue">void</span> g_relation_insert (<em class="parameter"><code><a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a> *relation</code></em>, |
| <em class="parameter"><code>...</code></em>);</pre> |
| <p> |
| Inserts a record into a <a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a>. |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>relation</code></em> :</span></p></td> |
| <td>a <a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a>. |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>...</code></em> :</span></p></td> |
| <td>the fields of the record to add. These must match the |
| number of fields in the <a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a>, and of type <a class="link" href="glib-Basic-Types.html#gpointer" title="gpointer"><span class="type">gpointer</span></a> |
| or <a class="link" href="glib-Basic-Types.html#gconstpointer" title="gconstpointer"><span class="type">gconstpointer</span></a>. |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="g_relation_exists ()"> |
| <a name="g-relation-exists"></a><h3>g_relation_exists ()</h3> |
| <pre class="programlisting"><a class="link" href="glib-Basic-Types.html#gboolean" title="gboolean"><span class="returnvalue">gboolean</span></a> g_relation_exists (<em class="parameter"><code><a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a> *relation</code></em>, |
| <em class="parameter"><code>...</code></em>);</pre> |
| <p> |
| Returns <a class="link" href="glib-Standard-Macros.html#TRUE:CAPS" title="TRUE"><code class="literal">TRUE</code></a> if a record with the given values exists in a |
| <a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a>. Note that the values are compared directly, so that, for |
| example, two copies of the same string will not match. |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>relation</code></em> :</span></p></td> |
| <td>a <a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a>. |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>...</code></em> :</span></p></td> |
| <td>the fields of the record to compare. The number must match |
| the number of fields in the <a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a>. |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td> |
| <a class="link" href="glib-Standard-Macros.html#TRUE:CAPS" title="TRUE"><code class="literal">TRUE</code></a> if a record matches. |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="g_relation_count ()"> |
| <a name="g-relation-count"></a><h3>g_relation_count ()</h3> |
| <pre class="programlisting"><a class="link" href="glib-Basic-Types.html#gint" title="gint"><span class="returnvalue">gint</span></a> g_relation_count (<em class="parameter"><code><a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a> *relation</code></em>, |
| <em class="parameter"><code><a class="link" href="glib-Basic-Types.html#gconstpointer" title="gconstpointer"><span class="type">gconstpointer</span></a> key</code></em>, |
| <em class="parameter"><code><a class="link" href="glib-Basic-Types.html#gint" title="gint"><span class="type">gint</span></a> field</code></em>);</pre> |
| <p> |
| Returns the number of tuples in a <a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a> that have the given |
| value in the given field. |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>relation</code></em> :</span></p></td> |
| <td>a <a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a>. |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>key</code></em> :</span></p></td> |
| <td>the value to compare with. |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>field</code></em> :</span></p></td> |
| <td>the field of each record to match. |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td>the number of matches. |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="g_relation_select ()"> |
| <a name="g-relation-select"></a><h3>g_relation_select ()</h3> |
| <pre class="programlisting"><a class="link" href="glib-Relations-and-Tuples.html#GTuples" title="GTuples"><span class="returnvalue">GTuples</span></a>* g_relation_select (<em class="parameter"><code><a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a> *relation</code></em>, |
| <em class="parameter"><code><a class="link" href="glib-Basic-Types.html#gconstpointer" title="gconstpointer"><span class="type">gconstpointer</span></a> key</code></em>, |
| <em class="parameter"><code><a class="link" href="glib-Basic-Types.html#gint" title="gint"><span class="type">gint</span></a> field</code></em>);</pre> |
| <p> |
| Returns all of the tuples which have the given key in the given |
| field. Use <a class="link" href="glib-Relations-and-Tuples.html#g-tuples-index" title="g_tuples_index ()"><code class="function">g_tuples_index()</code></a> to access the returned records. The |
| returned records should be freed with <a class="link" href="glib-Relations-and-Tuples.html#g-tuples-destroy" title="g_tuples_destroy ()"><code class="function">g_tuples_destroy()</code></a>. |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>relation</code></em> :</span></p></td> |
| <td>a <a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a>. |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>key</code></em> :</span></p></td> |
| <td>the value to compare with. |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>field</code></em> :</span></p></td> |
| <td>the field of each record to match. |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td>the records (tuples) that matched. |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="g_relation_delete ()"> |
| <a name="g-relation-delete"></a><h3>g_relation_delete ()</h3> |
| <pre class="programlisting"><a class="link" href="glib-Basic-Types.html#gint" title="gint"><span class="returnvalue">gint</span></a> g_relation_delete (<em class="parameter"><code><a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a> *relation</code></em>, |
| <em class="parameter"><code><a class="link" href="glib-Basic-Types.html#gconstpointer" title="gconstpointer"><span class="type">gconstpointer</span></a> key</code></em>, |
| <em class="parameter"><code><a class="link" href="glib-Basic-Types.html#gint" title="gint"><span class="type">gint</span></a> field</code></em>);</pre> |
| <p> |
| Deletes any records from a <a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a> that have the given key value |
| in the given field. |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>relation</code></em> :</span></p></td> |
| <td>a <a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a>. |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>key</code></em> :</span></p></td> |
| <td>the value to compare with. |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>field</code></em> :</span></p></td> |
| <td>the field of each record to match. |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td>the number of records deleted. |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="g_relation_destroy ()"> |
| <a name="g-relation-destroy"></a><h3>g_relation_destroy ()</h3> |
| <pre class="programlisting"><span class="returnvalue">void</span> g_relation_destroy (<em class="parameter"><code><a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a> *relation</code></em>);</pre> |
| <p> |
| Destroys the <a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a>, freeing all memory allocated. However, it |
| does not free memory allocated for the tuple data, so you should |
| free that first if appropriate. |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody><tr> |
| <td><p><span class="term"><em class="parameter"><code>relation</code></em> :</span></p></td> |
| <td>a <a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a>. |
| </td> |
| </tr></tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="g_relation_print ()"> |
| <a name="g-relation-print"></a><h3>g_relation_print ()</h3> |
| <pre class="programlisting"><span class="returnvalue">void</span> g_relation_print (<em class="parameter"><code><a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a> *relation</code></em>);</pre> |
| <p> |
| Outputs information about all records in a <a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a>, as well as |
| the indexes. It is for debugging. |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody><tr> |
| <td><p><span class="term"><em class="parameter"><code>relation</code></em> :</span></p></td> |
| <td>a <a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a>. |
| </td> |
| </tr></tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="GTuples"> |
| <a name="GTuples"></a><h3>GTuples</h3> |
| <pre class="programlisting">typedef struct { |
| guint len; |
| } GTuples; |
| </pre> |
| <p> |
| The <a class="link" href="glib-Relations-and-Tuples.html#GTuples" title="GTuples"><span class="type">GTuples</span></a> struct is used to return records (or tuples) from the |
| <a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a> by <a class="link" href="glib-Relations-and-Tuples.html#g-relation-select" title="g_relation_select ()"><code class="function">g_relation_select()</code></a>. It only contains one public |
| member - the number of records that matched. To access the matched |
| records, you must use <a class="link" href="glib-Relations-and-Tuples.html#g-tuples-index" title="g_tuples_index ()"><code class="function">g_tuples_index()</code></a>. |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody><tr> |
| <td><p><span class="term"><a class="link" href="glib-Basic-Types.html#guint" title="guint"><span class="type">guint</span></a> <em class="structfield"><code><a name="GTuples.len"></a>len</code></em>;</span></p></td> |
| <td>the number of records that matched. |
| </td> |
| </tr></tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="g_tuples_destroy ()"> |
| <a name="g-tuples-destroy"></a><h3>g_tuples_destroy ()</h3> |
| <pre class="programlisting"><span class="returnvalue">void</span> g_tuples_destroy (<em class="parameter"><code><a class="link" href="glib-Relations-and-Tuples.html#GTuples" title="GTuples"><span class="type">GTuples</span></a> *tuples</code></em>);</pre> |
| <p> |
| Frees the records which were returned by <a class="link" href="glib-Relations-and-Tuples.html#g-relation-select" title="g_relation_select ()"><code class="function">g_relation_select()</code></a>. This |
| should always be called after <a class="link" href="glib-Relations-and-Tuples.html#g-relation-select" title="g_relation_select ()"><code class="function">g_relation_select()</code></a> when you are |
| finished with the records. The records are not removed from the |
| <a class="link" href="glib-Relations-and-Tuples.html#GRelation" title="GRelation"><span class="type">GRelation</span></a>. |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody><tr> |
| <td><p><span class="term"><em class="parameter"><code>tuples</code></em> :</span></p></td> |
| <td>the tuple data to free. |
| </td> |
| </tr></tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="g_tuples_index ()"> |
| <a name="g-tuples-index"></a><h3>g_tuples_index ()</h3> |
| <pre class="programlisting"><a class="link" href="glib-Basic-Types.html#gpointer" title="gpointer"><span class="returnvalue">gpointer</span></a> g_tuples_index (<em class="parameter"><code><a class="link" href="glib-Relations-and-Tuples.html#GTuples" title="GTuples"><span class="type">GTuples</span></a> *tuples</code></em>, |
| <em class="parameter"><code><a class="link" href="glib-Basic-Types.html#gint" title="gint"><span class="type">gint</span></a> index_</code></em>, |
| <em class="parameter"><code><a class="link" href="glib-Basic-Types.html#gint" title="gint"><span class="type">gint</span></a> field</code></em>);</pre> |
| <p> |
| Gets a field from the records returned by <a class="link" href="glib-Relations-and-Tuples.html#g-relation-select" title="g_relation_select ()"><code class="function">g_relation_select()</code></a>. It |
| returns the given field of the record at the given index. The |
| returned value should not be changed. |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>tuples</code></em> :</span></p></td> |
| <td>the tuple data, returned by <a class="link" href="glib-Relations-and-Tuples.html#g-relation-select" title="g_relation_select ()"><code class="function">g_relation_select()</code></a>. |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>index_</code></em> :</span></p></td> |
| <td>the index of the record. |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>field</code></em> :</span></p></td> |
| <td>the field to return. |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td>the field of the record. |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| </div> |
| </div> |
| <div class="footer"> |
| <hr> |
| Generated by GTK-Doc V1.14</div> |
| </body> |
| </html> |
