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
167
168
169
170
171
172
173
174
175
176
|
<!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>SQL Keyword Checking</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_keyword_check sqlite3_keyword_count sqlite3_keyword_name -->
<div class=nosearch>
<a href="../c3ref/intro.html"><h2>SQLite C Interface</h2></a>
<h2>SQL Keyword Checking</h2>
</div>
<blockquote><pre>
int sqlite3_keyword_count(void);
int sqlite3_keyword_name(int,const char**,int*);
int sqlite3_keyword_check(const char*,int);
</pre></blockquote>
<p>
These routines provide access to the set of SQL language keywords
recognized by SQLite. Applications can uses these routines to determine
whether or not a specific identifier needs to be escaped (for example,
by enclosing in double-quotes) so as not to confuse the parser.</p>
<p>The sqlite3_keyword_count() interface returns the number of distinct
keywords understood by SQLite.</p>
<p>The sqlite3_keyword_name(N,Z,L) interface finds the 0-based N-th keyword and
makes *Z point to that keyword expressed as UTF8 and writes the number
of bytes in the keyword into *L. The string that *Z points to is not
zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns
SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z
or L are NULL or invalid pointers then calls to
sqlite3_keyword_name(N,Z,L) result in undefined behavior.</p>
<p>The sqlite3_keyword_check(Z,L) interface checks to see whether or not
the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero
if it is and zero if not.</p>
<p>The parser used by SQLite is forgiving. It is often possible to use
a keyword as an identifier as long as such use does not result in a
parsing ambiguity. For example, the statement
"CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and
creates a new table named "BEGIN" with three columns named
"REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid
using keywords as identifiers. Common techniques used to avoid keyword
name collisions include:
<ul>
<li> Put all identifier names inside double-quotes. This is the official
SQL way to escape identifier names.
<li> Put identifier names inside [...]. This is not standard SQL,
but it is what SQL Server does and so lots of programmers use this
technique.
<li> Begin every identifier with the letter "Z" as no SQL keywords start
with "Z".
<li> Include a digit somewhere in every identifier name.
</ul></p>
<p>Note that the number of keywords understood by SQLite can depend on
compile-time options. For example, "VACUUM" is not a keyword if
SQLite is compiled with the <a href="../compile.html#omit_vacuum">-DSQLITE_OMIT_VACUUM</a> option. Also,
new keywords may be added to future releases of SQLite.
</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>
|
