Author: slebresne
Date: Fri Jul 26 16:02:29 2013
New Revision: 1507361
URL: http://svn.apache.org/r1507361
Log:
Update CQL doc on website too
Modified:
cassandra/site/publish/doc/cql3/CQL.html
Modified: cassandra/site/publish/doc/cql3/CQL.html
URL:
http://svn.apache.org/viewvc/cassandra/site/publish/doc/cql3/CQL.html?rev=1507361&r1=1507360&r2=1507361&view=diff
==============================================================================
--- cassandra/site/publish/doc/cql3/CQL.html (original)
+++ cassandra/site/publish/doc/cql3/CQL.html Fri Jul 26 16:02:29 2013
@@ -1,7 +1,9 @@
<?xml version='1.0' encoding='utf-8' ?><!DOCTYPE html PUBLIC "-//W3C//DTD
XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd";><html
xmlns="http://www.w3.org/1999/xhtml";><head><meta http-equiv="Content-Type"
content="text/html; charset=utf-8"/><title>CQL</title></head><body><p><link
rel="StyleSheet" href="CQL.css" type="text/css" media="screen"></p><h1
id="CassandraQueryLanguageCQLv3.0.4">Cassandra Query Language (CQL)
v3.0.4</h1><span id="tableOfContents"><ol style="list-style: none;"><li><a
href="CQL.html#CassandraQueryLanguageCQLv3.0.4">Cassandra Query Language (CQL)
v3.0.4</a><ol style="list-style: none;"><li><a href="CQL.html#CQLSyntax">CQL
Syntax</a><ol style="list-style: none;"><li><a
href="CQL.html#Preamble">Preamble</a></li><li><a
href="CQL.html#Conventions">Conventions</a></li><li><a
href="CQL.html#identifiers">Identifiers and keywords</a></li><li><a
href="CQL.html#constants">Constants</a></li><li><a
href="CQL.html#Comments">Comments</a></l
i><li><a href="CQL.html#statements">Statements</a></li><li><a
href="CQL.html#preparedStatement">Prepared Statement</a></li></ol></li><li><a
href="CQL.html#dataDefinition">Data Definition</a><ol style="list-style:
none;"><li><a href="CQL.html#createKeyspaceStmt">CREATE KEYSPACE</a></li><li><a
href="CQL.html#useStmt">USE</a></li><li><a
href="CQL.html#alterKeyspaceStmt">ALTER KEYSPACE</a></li><li><a
href="CQL.html#dropKeyspaceStmt">DROP KEYSPACE</a></li><li><a
href="CQL.html#createTableStmt">CREATE TABLE</a></li><li><a
href="CQL.html#alterTableStmt">ALTER TABLE</a></li><li><a
href="CQL.html#dropTableStmt">DROP TABLE</a></li><li><a
href="CQL.html#truncateStmt">TRUNCATE</a></li><li><a
href="CQL.html#createIndexStmt">CREATE INDEX</a></li><li><a
href="CQL.html#dropIndexStmt">DROP INDEX</a></li></ol></li><li><a
href="CQL.html#dataManipulation">Data Manipulation</a><ol style="list-style:
none;"><li><a href="CQL.html#insertStmt">INSERT</a></li><li><a
href="CQL.html#updateStmt">UPDATE</a></li>
<li><a href="CQL.html#deleteStmt">DELETE</a></li><li><a
href="CQL.html#batchStmt">BATCH</a></li></ol></li><li><a
href="CQL.html#queries">Queries</a><ol style="list-style: none;"><li><a
href="CQL.html#selectStmt">SELECT</a></li></ol></li><li><a
href="CQL.html#types">Data Types</a><ol style="list-style: none;"><li><a
href="CQL.html#usingdates">Working with dates</a></li><li><a
href="CQL.html#counters">Counters</a></li><li><a
href="CQL.html#collections">Working with collections</a></li></ol></li><li><a
href="CQL.html#functions">Functions</a><ol style="list-style: none;"><li><a
href="CQL.html#tokenFun">Token</a></li><li><a
href="CQL.html#timeuuidFun">Timeuuid functions</a></li><li><a
href="CQL.html#blobFun">Blob conversion functions</a></li></ol></li><li><a
href="CQL.html#appendixA">Appendix A: CQL Keywords</a></li><li><a
href="CQL.html#changes">Changes</a><ol style="list-style: none;"><li><a
href="CQL.html#a3.0.4">3.0.4</a></li><li><a
href="CQL.html#a3.0.3">3.0.3</a></li><li><a href="C
QL.html#a3.0.2">3.0.2</a></li><li><a
href="CQL.html#a3.0.1">3.0.1</a></li></ol></li><li><a
href="CQL.html#Versioning">Versioning</a></li></ol></li></ol></span><h2
id="CQLSyntax">CQL Syntax</h2><h3 id="Preamble">Preamble</h3><p>This document
describes the Cassandra Query Language (CQL) version 3. CQL v3 is not backward
compatible with CQL v2 and differs from it in numerous ways. Note that this
document describes the last version of the languages. However, the <a
href="#changes">changes</a> section provides the diff between the different
versions of CQL v3.</p><p>CQL v3 offers a model very close to SQL in the sense
that data is put in <em>tables</em> containing <em>rows</em> of
<em>columns</em>. For that reason, when used in this document, these terms
(tables, rows and columns) have the same definition than they have in SQL. But
please note that as such, they do <strong>not</strong> refer to the concept of
rows and columns found in the internal implementation of Cassandra and in the t
hrift and CQL v2 API.</p><h3 id="Conventions">Conventions</h3><p>To aid in
specifying the CQL syntax, we will use the following conventions in this
document:</p><ul><li>Language rules will be given in a <a
href="http://en.wikipedia.org/wiki/Backus%E2%80%93Naur_Form";>BNF</a> -like
notation:</li></ul><pre class="syntax"><pre><start> ::= TERMINAL
<non-terminal1> <non-terminal1>
</pre></pre><ul><li>Nonterminal symbols will have <code><angle
brackets></code>.</li><li>As additional shortcut notations to BNF, we’ll
use traditional regular expression’s symbols (<code>?</code>,
<code>+</code> and <code>*</code>) to signify that a given symbol is optional
and/or can be repeated. We’ll also allow parentheses to group symbols and
the <code>[<characters>]</code> notation to represent any one of
<code><characters></code>.</li><li>The grammar is provided for documentation
purposes and leave some minor details out. For instance, the last column
definition in a <code>CREATE TABLE</code> statement is optional but supported
if present even though the provided grammar in this document suggest it is not
supported. </li><li>Sample code will be provided in a code block:</li></ul><pre
class="sample"><pre>SELECT sample_usage FROM cql;
-</pre></pre><ul><li>References to keywords or pieces of CQL code in running
text will be shown in a <code>fixed-width font</code>.</li></ul><h3
id="identifiers">Identifiers and keywords</h3><p>The CQL language uses
<em>identifiers</em> (or <em>names</em>) to identify tables, columns and other
objects. An identifier is a token matching the regular expression <code
lang="a-zA-Z">[a-zA-Z0-9_]</code><code>*</code>.</p><p>A number of such
identifiers, like <code>SELECT</code> or <code>WITH</code>, are
<em>keywords</em>. They have a fixed meaning for the language and most are
reserved. The list of those keywords can be found in <a
href="#appendixA">Appendix A</a>.</p><p>Identifiers and (unquoted) keywords are
case insensitive. Thus <code>SELECT</code> is the same than <code>select</code>
or <code>sElEcT</code>, and <code>myId</code> is the same than
<code>myid</code> or <code>MYID</code> for instance. A convention often used
(in particular by the samples of this documentation) is to use u
pper case for keywords and lower case for other identifiers.</p><p>There is a
second kind of identifiers called <em>quoted identifiers</em> defined by
enclosing an arbitrary sequence of characters in double-quotes(<code>"</code>).
Quoted identifiers are never keywords. Thus <code>"select"</code> is not a
reserved keyword and can be used to refer to a column, while
<code>select</code> would raise a parse error. Also, contrarily to unquoted
identifiers and keywords, quoted identifiers are case sensitive (<code>"My
Quoted Id"</code> is <em>different</em> from <code>"my quoted id"</code>). A
fully lowercase quoted identifier that matches <code
lang="a-zA-Z">[a-zA-Z0-9_]</code><code>*</code> is equivalent to the unquoted
identifier obtained by removing the double-quote (so <code>"myid"</code> is
equivalent to <code>myid</code> and to <code>myId</code> but different from
<code>"myId"</code>). Inside a quoted identifier, the double-quote character
can be repeated to escape it, so <code>"fo
o "" bar"</code> is a valid identifier.</p><h3
id="constants">Constants</h3><p>CQL defines the following kind of
<em>constants</em>: strings, integers, floats, booleans, uuids and
blobs:</p><ul><li>A string constant is an arbitrary sequence of characters
characters enclosed by single-quote(<code>'</code>). One can include a
single-quote in a string by repeating it, e.g. <code>'It''s raining
today'</code>. Those are not to be confused with quoted identifiers that use
double-quotes.</li><li>An integer constant is defined by
<code>'-'?[0-9]+</code>.</li><li>A float constant is defined by
<code>'-'?[0-9]+('.'[0-9]*)?([eE][+-]?[0-9+])?</code>.</li><li>A boolean
constant is either <code>true</code> or <code>false</code> up to
case-insensitivity (i.e. <code>True</code> is a valid boolean
constant).</li><li>A <a
href="http://en.wikipedia.org/wiki/Universally_unique_identifier";>UUID</a>
constant is defined by <code>hex{8}-hex{4}-hex{4}-hex{4}-hex{12}</code> where
<code>hex</code> is an hexad
ecimal character, e.g. <code>[0-9a-fA-F]</code> and <code>{4}</code> is the
number of such characters.</li><li>A blob constant is an hexadecimal number
defined by <code>0[xX](hex)+</code> where <code>hex</code> is an hexadecimal
character, e.g. <code>[0-9a-fA-F]</code>.</li></ul><p>For how these constants
are typed, see the <a href="#types">data types section</a>.</p><h3
id="Comments">Comments</h3><p>A comment in CQL is a line beginning by either
double dashes (<code>--</code>) or double slash (<code>//</code>).</p><pre
class="sample"><pre>-- This is a comment
+</pre></pre><ul><li>References to keywords or pieces of CQL code in running
text will be shown in a <code>fixed-width font</code>.</li></ul><h3
id="identifiers">Identifiers and keywords</h3><p>The CQL language uses
<em>identifiers</em> (or <em>names</em>) to identify tables, columns and other
objects. An identifier is a token matching the regular expression <code
lang="a-zA-Z">[a-zA-Z0-9_]</code><code>*</code>.</p><p>A number of such
identifiers, like <code>SELECT</code> or <code>WITH</code>, are
<em>keywords</em>. They have a fixed meaning for the language and most are
reserved. The list of those keywords can be found in <a
href="#appendixA">Appendix A</a>.</p><p>Identifiers and (unquoted) keywords are
case insensitive. Thus <code>SELECT</code> is the same than <code>select</code>
or <code>sElEcT</code>, and <code>myId</code> is the same than
<code>myid</code> or <code>MYID</code> for instance. A convention often used
(in particular by the samples of this documentation) is to use u
pper case for keywords and lower case for other identifiers.</p><p>There is a
second kind of identifiers called <em>quoted identifiers</em> defined by
enclosing an arbitrary sequence of characters in double-quotes(<code>"</code>).
Quoted identifiers are never keywords. Thus <code>"select"</code> is not a
reserved keyword and can be used to refer to a column, while
<code>select</code> would raise a parse error. Also, contrarily to unquoted
identifiers and keywords, quoted identifiers are case sensitive (<code>"My
Quoted Id"</code> is <em>different</em> from <code>"my quoted id"</code>). A
fully lowercase quoted identifier that matches <code
lang="a-zA-Z">[a-zA-Z0-9_]</code><code>*</code> is equivalent to the unquoted
identifier obtained by removing the double-quote (so <code>"myid"</code> is
equivalent to <code>myid</code> and to <code>myId</code> but different from
<code>"myId"</code>). Inside a quoted identifier, the double-quote character
can be repeated to escape it, so <code>"fo
o "" bar"</code> is a valid identifier.</p><h3
id="constants">Constants</h3><p>CQL defines the following kind of
<em>constants</em>: strings, integers, floats, booleans, uuids and
blobs:</p><ul><li>A string constant is an arbitrary sequence of characters
characters enclosed by single-quote(<code>'</code>). One can include a
single-quote in a string by repeating it, e.g. <code>'It''s raining
today'</code>. Those are not to be confused with quoted identifiers that use
double-quotes.</li><li>An integer constant is defined by
<code>'-'?[0-9]+</code>.</li><li>A float constant is defined by
<code>'-'?[0-9]+('.'[0-9]*)?([eE][+-]?[0-9+])?</code>.</li><li>A boolean
constant is either <code>true</code> or <code>false</code> up to
case-insensitivity (i.e. <code>True</code> is a valid boolean
constant).</li><li>A <a
href="http://en.wikipedia.org/wiki/Universally_unique_identifier";>UUID</a>
constant is defined by <code>hex{8}-hex{4}-hex{4}-hex{4}-hex{12}</code> where
<code>hex</code> is an hexad
ecimal character, e.g. <code>[0-9a-fA-F]</code> and <code>{4}</code> is the
number of such characters.</li><li>A blob constant is an hexadecimal number
defined by <code>0[xX](hex)+</code> where <code>hex</code> is an hexadecimal
character, e.g. <code>[0-9a-fA-F]</code>.</li></ul><p>For how these constants
are typed, see the <a href="#types">data types section</a>.</p><h3
id="Comments">Comments</h3><p>A comment in CQL is a line beginning by either
double dashes (<code>--</code>) or double slash
(<code>//</code>).</p><p>Multi-line comments are also supported through
enclosure withing <code>/*</code> and <code>*/</code> (but nesting is not
supported).</p><pre class="sample"><pre>-- This is a comment
// This is a comment too
+/* This is
+ a multiline comment */
</pre></pre><h3 id="statements">Statements</h3><p>CQL consists of statements.
As in SQL, these statements can be divided in 3 categories:</p><ul><li>Data
definition statements, that allow to set and change the way data is
stored.</li><li>Data manipulation statements, that allow to change
data</li><li>Queries, to look up data</li></ul><p>All statements end with a
semicolon (<code>;</code>) but that semicolon can be omitted when dealing with
a single statement. The supported statements are described in the following
sections. When describing the grammar of said statements, we will reuse the
non-terminal symbols defined below:</p><pre class="syntax"><pre><identifier>
::= any quoted or unquoted identifier, excluding reserved keywords
<tablename> ::= (<identifier> '.')? <identifier>
