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
165
166
|
<!DOCTYPE html>
<html><head>
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<link href="../sqlite.css" rel="stylesheet">
<title>Constraint values in xBestIndex()</title>
<!-- path=../ -->
</head>
<body>
<div class=nosearch>
<a href="../index.html">
<img class="logo" src="../images/sqlite370_banner.gif" alt="SQLite" border="0">
</a>
<div><!-- IE hack to prevent disappearing logo --></div>
<div class="tagline desktoponly">
Small. Fast. Reliable.<br>Choose any three.
</div>
<div class="menu mainmenu">
<ul>
<li><a href="../index.html">Home</a>
<li class='mobileonly'><a href="javascript:void(0)" onclick='toggle_div("submenu")'>Menu</a>
<li class='wideonly'><a href='../about.html'>About</a>
<li class='desktoponly'><a href="../docs.html">Documentation</a>
<li class='desktoponly'><a href="../download.html">Download</a>
<li class='wideonly'><a href='../copyright.html'>License</a>
<li class='desktoponly'><a href="../support.html">Support</a>
<li class='desktoponly'><a href="../prosupport.html">Purchase</a>
<li class='search' id='search_menubutton'>
<a href="javascript:void(0)" onclick='toggle_search()'>Search</a>
</ul>
</div>
<div class="menu submenu" id="submenu">
<ul>
<li><a href='../about.html'>About</a>
<li><a href='../docs.html'>Documentation</a>
<li><a href='../download.html'>Download</a>
<li><a href='../support.html'>Support</a>
<li><a href='../prosupport.html'>Purchase</a>
</ul>
</div>
<div class="searchmenu" id="searchmenu">
<form method="GET" action="../search">
<select name="s" id="searchtype">
<option value="d">Search Documentation</option>
<option value="c">Search Changelog</option>
</select>
<input type="text" name="q" id="searchbox" value="">
<input type="submit" value="Go">
</form>
</div>
</div>
<script>
function toggle_div(nm) {
var w = document.getElementById(nm);
if( w.style.display=="block" ){
w.style.display = "none";
}else{
w.style.display = "block";
}
}
function toggle_search() {
var w = document.getElementById("searchmenu");
if( w.style.display=="block" ){
w.style.display = "none";
} else {
w.style.display = "block";
setTimeout(function(){
document.getElementById("searchbox").focus()
}, 30);
}
}
function div_off(nm){document.getElementById(nm).style.display="none";}
window.onbeforeunload = function(e){div_off("submenu");}
/* Disable the Search feature if we are not operating from CGI, since */
/* Search is accomplished using CGI and will not work without it. */
if( !location.origin || !location.origin.match || !location.origin.match(/http/) ){
document.getElementById("search_menubutton").style.display = "none";
}
/* Used by the Hide/Show button beside syntax diagrams, to toggle the */
function hideorshow(btn,obj){
var x = document.getElementById(obj);
var b = document.getElementById(btn);
if( x.style.display!='none' ){
x.style.display = 'none';
b.innerHTML='show';
}else{
x.style.display = '';
b.innerHTML='hide';
}
return false;
}
var antiRobot = 0;
function antiRobotGo(){
if( antiRobot!=3 ) return;
antiRobot = 7;
var j = document.getElementById("mtimelink");
if(j && j.hasAttribute("data-href")) j.href=j.getAttribute("data-href");
}
function antiRobotDefense(){
document.body.onmousedown=function(){
antiRobot |= 2;
antiRobotGo();
document.body.onmousedown=null;
}
document.body.onmousemove=function(){
antiRobot |= 2;
antiRobotGo();
document.body.onmousemove=null;
}
setTimeout(function(){
antiRobot |= 1;
antiRobotGo();
}, 100)
antiRobotGo();
}
antiRobotDefense();
</script>
<!-- keywords: sqlite3_vtab_rhs_value -->
<div class=nosearch>
<a href="../c3ref/intro.html"><h2>SQLite C Interface</h2></a>
<h2>Constraint values in xBestIndex()</h2>
</div>
<blockquote><pre>
int sqlite3_vtab_rhs_value(sqlite3_index_info*, int, sqlite3_value **ppVal);
</pre></blockquote>
<p>
This API may only be used from within the <a href="../vtab.html#xbestindex">xBestIndex method</a>
of a <a href="../vtab.html">virtual table</a> implementation. The result of calling this interface
from outside of an xBestIndex method are undefined and probably harmful.</p>
<p>When the sqlite3_vtab_rhs_value(P,J,V) interface is invoked from within
the <a href="../vtab.html#xbestindex">xBestIndex</a> method of a <a href="../vtab.html">virtual table</a> implementation, with P being
a copy of the <a href="../c3ref/index_info.html">sqlite3_index_info</a> object pointer passed into xBestIndex and
J being a 0-based index into P->aConstraint[], then this routine
attempts to set *V to the value of the right-hand operand of
that constraint if the right-hand operand is known. If the
right-hand operand is not known, then *V is set to a NULL pointer.
The sqlite3_vtab_rhs_value(P,J,V) interface returns SQLITE_OK if
and only if *V is set to a value. The sqlite3_vtab_rhs_value(P,J,V)
inteface returns SQLITE_NOTFOUND if the right-hand side of the J-th
constraint is not available. The sqlite3_vtab_rhs_value() interface
can return an result code other than SQLITE_OK or SQLITE_NOTFOUND if
something goes wrong.</p>
<p>The sqlite3_vtab_rhs_value() interface is usually only successful if
the right-hand operand of a constraint is a literal value in the original
SQL statement. If the right-hand operand is an expression or a reference
to some other column or a <a href="../c3ref/bind_blob.html">host parameter</a>, then sqlite3_vtab_rhs_value()
will probably return <a href="../rescode.html#notfound">SQLITE_NOTFOUND</a>.</p>
<p>Some constraints, such as <a href="../c3ref/c_index_constraint_eq.html">SQLITE_INDEX_CONSTRAINT_ISNULL</a> and
<a href="../c3ref/c_index_constraint_eq.html">SQLITE_INDEX_CONSTRAINT_ISNOTNULL</a>, have no right-hand operand. For such
constraints, sqlite3_vtab_rhs_value() always returns SQLITE_NOTFOUND.</p>
<p>The <a href="../c3ref/value.html">sqlite3_value</a> object returned in *V is a protected sqlite3_value
and remains valid for the duration of the xBestIndex method call.
When xBestIndex returns, the sqlite3_value object returned by
sqlite3_vtab_rhs_value() is automatically deallocated.</p>
<p>The "_rhs_" in the name of this routine is an abbreviation for
"Right-Hand Side".
</p><p>See also lists of
<a href="../c3ref/objlist.html">Objects</a>,
<a href="../c3ref/constlist.html">Constants</a>, and
<a href="../c3ref/funclist.html">Functions</a>.</p>
|
