diff options
Diffstat (limited to 'www/c3ref/column_decltype.html')
-rw-r--r-- | www/c3ref/column_decltype.html | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/www/c3ref/column_decltype.html b/www/c3ref/column_decltype.html new file mode 100644 index 0000000..1297fe7 --- /dev/null +++ b/www/c3ref/column_decltype.html @@ -0,0 +1,157 @@ +<!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>Declared Datatype Of A Query Result</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_column_decltype sqlite3_column_decltype16 --> +<div class=nosearch> +<a href="../c3ref/intro.html"><h2>SQLite C Interface</h2></a> +<h2>Declared Datatype Of A Query Result</h2> +</div> +<blockquote><pre> +const char *sqlite3_column_decltype(sqlite3_stmt*,int); +const void *sqlite3_column_decltype16(sqlite3_stmt*,int); +</pre></blockquote> +<p> +The first parameter is a <a href="../c3ref/stmt.html">prepared statement</a>. +If this statement is a <a href="../lang_select.html">SELECT</a> statement and the Nth column of the +returned result set of that <a href="../lang_select.html">SELECT</a> is a table column (not an +expression or subquery) then the declared type of the table +column is returned. If the Nth column of the result set is an +expression or subquery, then a NULL pointer is returned. +The returned string is always UTF-8 encoded.</p> + +<p>For example, given the database schema:</p> + +<p>CREATE TABLE t1(c1 VARIANT);</p> + +<p>and the following statement to be compiled:</p> + +<p>SELECT c1 + 1, c1 FROM t1;</p> + +<p>this routine would return the string "VARIANT" for the second result +column (i==1), and a NULL pointer for the first result column (i==0).</p> + +<p>SQLite uses dynamic run-time typing. So just because a column +is declared to contain a particular type does not mean that the +data stored in that column is of the declared type. SQLite is +strongly typed, but the typing is dynamic not static. Type +is associated with individual values, not with the containers +used to hold those values. +</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> + |