📄 sql_select.asp
字号:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html lang="en-US" xml:lang="en-US" xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>SQL SELECT Statement</title>
<link rel="shortcut icon" href="../favicon.ico" type="image/x-icon" />
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1" />
<meta name="Keywords" content="xml,tutorial,html,dhtml,css,xsl,xhtml,javascript,asp,ado,vbscript,dom,sql,colors,soap,php,authoring,programming,training,learning,beginner's guide,primer,lessons,school,howto,reference,examples,samples,source code,tags,demos,tips,links,FAQ,tag list,forms,frames,color table,w3c,cascading style sheets,active server pages,dynamic html,internet,database,development,Web building,Webmaster,html guide" />
<meta name="Description" content="Well organized easy to understand SQL tutorial with lots of examples. Including PHP, ASP, ADO, Oracle, Access, SQL Server. Related: HTML, JavaScript, XML, XQuery" />
<meta http-equiv="pragma" content="no-cache" />
<meta http-equiv="cache-control" content="no-cache" />
<link rel="stylesheet" type="text/css" href="../stdtheme.css" />
<script type="text/javascript">
var gaJsHost = (("https:" == document.location.protocol) ? "../../https@ssl./default.htm" : "../../www./default.htm");
document.write(unescape("%3Cscript src='" + gaJsHost + "google-analytics.com/ga.js' type='text/javascript'%3E%3C/script%3E"));
</script>
<script type="text/javascript">
var pageTracker = _gat._getTracker("UA-3855518-1");
pageTracker._initData();
pageTracker._trackPageview();
</script>
</head>
<body>
<a name="top"></a>
<table cellpadding="0" cellspacing="0" width="100%" bgcolor="#808080">
<tr>
<td width="234" valign="top">
<a href="../default.htm"><img src="../images/w3default80.jpg" border="0" alt="W3Schools" /></a>
</td>
<th valign="middle" align="left" class="right">
<script type="text/javascript"><!--
google_ad_client = "pub-3440800076797949";
/*txtimg*/
google_ad_slot = "5330033957";
google_ad_width = 728;
google_ad_height = 90;
//-->
</script>
<script type="text/javascript" src="../../pagead2.googlesyndication.com/pagead/show_ads.js">
</script>
<noscript>
<a href="../default.asp" target="_blank"><img src="../banners/w6.gif" border="0" alt="W3Schools" /></a>
</noscript>
<br /></th>
</tr>
</table>
<table style="margin-left:1px" width="800px" border="0" cellpadding="0" cellspacing="2">
<tr>
<td width="137" class="content" valign="top"><br />
<a class="left" href="../default.asp" target="_top">
<img src="../images/homeicon.gif" border="0" alt="home" /></a>
<a class="left" href="../default.asp" target="_top">
<b>HOME</b></a>
<br /><br />
<b>SQL Basic</b>
<br />
<a class="left" target="_top" href="default.asp" >SQL HOME</a><br />
<a class="left" target="_top" href="sql_intro.asp" >SQL Intro</a><br />
<a class="left" target="_top" href="sql_select.asp" style='font-weight:bold;'>SQL Select</a><br />
<a class="left" target="_top" href="sql_where.asp" >SQL Where</a><br />
<a class="left" target="_top" href="sql_insert.asp" >SQL Insert</a><br />
<a class="left" target="_top" href="sql_update.asp" >SQL Update</a><br />
<a class="left" target="_top" href="sql_delete.asp" >SQL Delete</a><br />
<br />
<b>SQL Demo</b><br />
<a class="left" target="_top" href="sql_tryit.asp" >SQL Try It</a><br />
<br />
<b>SQL Advanced</b><br />
<a class="left" target="_top" href="sql_orderby.asp" >SQL Order By</a><br />
<a class="left" target="_top" href="sql_and_or.asp" >SQL and & or</a><br />
<a class="left" target="_top" href="sql_in.asp" >SQL In</a><br />
<a class="left" target="_top" href="sql_between.asp" >SQL Between</a><br />
<a class="left" target="_top" href="sql_alias.asp" >SQL Aliases</a><br />
<a class="left" target="_top" href="sql_join.asp" >SQL Join</a><br />
<a class="left" target="_top" href="sql_union.asp" >SQL Union</a><br />
<a class="left" target="_top" href="sql_create.asp" >SQL Create</a><br />
<a class="left" target="_top" href="sql_drop.asp" >SQL Drop</a><br />
<a class="left" target="_top" href="sql_alter.asp" >SQL Alter</a><br />
<a class="left" target="_top" href="sql_functions.asp" >SQL Functions</a><br />
<a class="left" target="_top" href="sql_groupby.asp" >SQL Group By</a><br />
<a class="left" target="_top" href="sql_select_into.asp" >SQL Select Into</a><br />
<a class="left" target="_top" href="sql_view.asp" >SQL Create View</a><br />
<a class="left" target="_top" href="sql_server.asp" >SQL Server</a><br />
<br />
<a class="left" target="_top" href="sql_quickref.asp" >SQL Quick Ref</a><br />
<a class="left" target="_top" href="sql_summary.asp" >SQL Summary</a><br />
<br />
<b>SQL Quiz</b><br />
<a class="left" target="_top" href="sql_quiz.asp" >SQL Quiz</a><br />
<br />
<b>Selected Reading</b><br />
<a class="left" target="_top" href="../browsers/browsers_stats.asp">Web Statistics</a><br />
<a class="left" target="_top" href="../site/site_glossary.asp">Web Glossary</a><br />
<a class="left" target="_top" href="../hosting/default.asp">Web Hosting</a><br />
<a class="left" target="_top" href="../quality/default.asp">Web Quality</a><br /><br />
<a class="left" target="_top" href="../forum/default.asp">W3Schools Forum</a><br /><br />
<a class="left" target="_top" href="../about/about_helping.asp">Helping W3Schools</a><br /><br />
<script type="text/javascript"><!--
google_ad_client = "pub-3440800076797949";
/*LeftLinkUnit*/
google_ad_slot = "4854527104";
google_ad_width = 120;
google_ad_height = 90;
//-->
</script>
<script type="text/javascript"
src="../../pagead2.googlesyndication.com/pagead/show_ads.js">
</script>
</td>
<td valign="top">
<table style="border: 1px solid gray" width="100%" bgcolor="#FFFFFF" border="0" cellpadding="5" cellspacing="0">
<tr>
<td>
<h1>SQL SELECT Statement</h1>
<a href="sql_intro.asp"><img border="0" alt="previous" src="../images/btn_previous.gif" width="100" height="20" /></a>
<a href="sql_where.asp"><img border="0" alt="next" src="../images/btn_next.gif" width="100" height="20" /></a>
<hr />
<h2>The SQL SELECT Statement</h2>
<p>The SELECT statement is used to select data from a table. The tabular result is stored in a result table (called the
result-set).</p>
<h3>Syntax</h3>
<table class="ex" cellspacing="0" border="1" width="100%">
<tr>
<td>
<pre>SELECT column_name(s)
FROM table_name</pre>
</td>
</tr>
</table>
<p><img src="lamp.gif" alt="Note" /> <b>Note:</b> SQL statements are not case
sensitive. SELECT is the same as select.</p>
<hr />
<h2>SQL SELECT Example</h2>
<p>To select the content of columns named "LastName" and "FirstName",
from the database table called "Persons", use
a SELECT
statement like this:</p>
<table class="ex" cellspacing="0" border="1" width="100%">
<tr>
<td>
<pre>SELECT LastName,FirstName FROM Persons</pre>
</td>
</tr>
</table>
<p><b>The database table "Persons":</b></p>
<table class="ex" cellspacing="0" border="1" width="100%">
<tr>
<th align="left">LastName</th>
<th align="left">FirstName</th>
<th align="left">Address</th>
<th align="left">City</th>
</tr>
<tr>
<td>Hansen</td>
<td>Ola</td>
<td>Timoteivn 10</td>
<td>Sandnes</td>
</tr>
<tr>
<td>Svendson</td>
<td>Tove</td>
<td>Borgvn 23</td>
<td>Sandnes</td>
</tr>
<tr>
<td>Pettersen</td>
<td>Kari</td>
<td>Storgt 20</td>
<td>Stavanger</td>
</tr>
</table>
<p><b>The result</b></p>
<table class="ex" cellspacing="0" border="1" width="50%">
<tr>
<th align="left">LastName</th>
<th align="left">FirstName</th>
</tr>
<tr>
<td>Hansen</td>
<td>Ola</td>
</tr>
<tr>
<td>Svendson</td>
<td>Tove</td>
</tr>
<tr>
<td>Pettersen</td>
<td>Kari</td>
</tr>
</table>
<br />
<hr />
<h2>Select All Columns</h2>
<p>To select all columns from the "Persons" table, use a * symbol
instead of column names, like
this: </p>
<table class="ex" cellspacing="0" border="1" width="100%">
<tr>
<td>
<pre>SELECT * FROM Persons</pre>
</td>
</tr>
</table>
<p><b>Result</b></p>
<table class="ex" cellspacing="0" border="1" width="100%">
<tr>
<th align="left">LastName</th>
<th align="left">FirstName</th>
<th align="left">Address</th>
<th align="left">City</th>
</tr>
<tr>
<td>Hansen</td>
<td>Ola</td>
<td>Timoteivn 10</td>
<td>Sandnes</td>
</tr>
<tr>
<td>Svendson</td>
<td>Tove</td>
<td>Borgvn 23</td>
<td>Sandnes</td>
</tr>
<tr>
<td>Pettersen</td>
<td>Kari</td>
<td>Storgt 20</td>
<td>Stavanger</td>
</tr>
</table>
<br />
<hr />
<h2>The Result Set</h2>
<p>The result from a SQL query is stored in a result-set. Most database software systems allow navigation of the
result set with programming functions, like: Move-To-First-Record,
Get-Record-Content, Move-To-Next-Record, etc.</p>
<p>Programming functions like these are not a part of this tutorial. To learn about accessing data with function calls,
please visit
our <a href="../ado/default.asp">ADO tutorial</a>. </p>
<hr />
<h2>Semicolon after SQL Statements?</h2>
<p>Semicolon is the standard way to separate each SQL statement in database systems that allow more than one
SQL statement to be executed in the same call to the server.</p>
<p>Some SQL tutorials end each SQL statement with a
semicolon. Is this necessary? We are using MS Access and SQL Server 2000 and we
do not have to put a semicolon after each SQL statement, but some database
programs force you to use it.</p>
<hr />
<h2>The SELECT DISTINCT Statement</h2>
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -