Symbian3/PDK/Source/GUID-C474376E-1766-5781-B5BF-3786C5B4D72E.dita
author Dominic Pinkman <Dominic.Pinkman@Nokia.com>
Thu, 11 Mar 2010 18:02:22 +0000
changeset 3 46218c8b8afa
parent 1 25a17d01db0c
child 5 f345bda72bc4
permissions -rw-r--r--
week 10 bug fix submission (SF PDK version): Bug 1892, Bug 1897, Bug 1319. Also 3 or 4 documents were found to contain code blocks with SFL, which has been fixed. Partial fix for broken links, links to Forum Nokia, and the 'Symbian platform' terminology issues.
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
3
46218c8b8afa week 10 bug fix submission (SF PDK version): Bug 1892, Bug 1897, Bug 1319. Also 3 or 4 documents were found to contain code blocks with SFL, which has been fixed. Partial fix for broken links, links to Forum Nokia, and the 'Symbian platform' terminology issues.
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents: 1
diff changeset
     1
<?xml version="1.0" encoding="utf-8"?>
46218c8b8afa week 10 bug fix submission (SF PDK version): Bug 1892, Bug 1897, Bug 1319. Also 3 or 4 documents were found to contain code blocks with SFL, which has been fixed. Partial fix for broken links, links to Forum Nokia, and the 'Symbian platform' terminology issues.
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents: 1
diff changeset
     2
<!-- Copyright (c) 2007-2010 Nokia Corporation and/or its subsidiary(-ies) All rights reserved. -->
46218c8b8afa week 10 bug fix submission (SF PDK version): Bug 1892, Bug 1897, Bug 1319. Also 3 or 4 documents were found to contain code blocks with SFL, which has been fixed. Partial fix for broken links, links to Forum Nokia, and the 'Symbian platform' terminology issues.
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents: 1
diff changeset
     3
<!-- This component and the accompanying materials are made available under the terms of the License 
46218c8b8afa week 10 bug fix submission (SF PDK version): Bug 1892, Bug 1897, Bug 1319. Also 3 or 4 documents were found to contain code blocks with SFL, which has been fixed. Partial fix for broken links, links to Forum Nokia, and the 'Symbian platform' terminology issues.
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents: 1
diff changeset
     4
"Eclipse Public License v1.0" which accompanies this distribution, 
46218c8b8afa week 10 bug fix submission (SF PDK version): Bug 1892, Bug 1897, Bug 1319. Also 3 or 4 documents were found to contain code blocks with SFL, which has been fixed. Partial fix for broken links, links to Forum Nokia, and the 'Symbian platform' terminology issues.
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents: 1
diff changeset
     5
and is available at the URL "http://www.eclipse.org/legal/epl-v10.html". -->
46218c8b8afa week 10 bug fix submission (SF PDK version): Bug 1892, Bug 1897, Bug 1319. Also 3 or 4 documents were found to contain code blocks with SFL, which has been fixed. Partial fix for broken links, links to Forum Nokia, and the 'Symbian platform' terminology issues.
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents: 1
diff changeset
     6
<!-- Initial Contributors:
46218c8b8afa week 10 bug fix submission (SF PDK version): Bug 1892, Bug 1897, Bug 1319. Also 3 or 4 documents were found to contain code blocks with SFL, which has been fixed. Partial fix for broken links, links to Forum Nokia, and the 'Symbian platform' terminology issues.
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents: 1
diff changeset
     7
    Nokia Corporation - initial contribution.
46218c8b8afa week 10 bug fix submission (SF PDK version): Bug 1892, Bug 1897, Bug 1319. Also 3 or 4 documents were found to contain code blocks with SFL, which has been fixed. Partial fix for broken links, links to Forum Nokia, and the 'Symbian platform' terminology issues.
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents: 1
diff changeset
     8
Contributors: 
46218c8b8afa week 10 bug fix submission (SF PDK version): Bug 1892, Bug 1897, Bug 1319. Also 3 or 4 documents were found to contain code blocks with SFL, which has been fixed. Partial fix for broken links, links to Forum Nokia, and the 'Symbian platform' terminology issues.
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents: 1
diff changeset
     9
-->
46218c8b8afa week 10 bug fix submission (SF PDK version): Bug 1892, Bug 1897, Bug 1319. Also 3 or 4 documents were found to contain code blocks with SFL, which has been fixed. Partial fix for broken links, links to Forum Nokia, and the 'Symbian platform' terminology issues.
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents: 1
diff changeset
    10
<!DOCTYPE concept
46218c8b8afa week 10 bug fix submission (SF PDK version): Bug 1892, Bug 1897, Bug 1319. Also 3 or 4 documents were found to contain code blocks with SFL, which has been fixed. Partial fix for broken links, links to Forum Nokia, and the 'Symbian platform' terminology issues.
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents: 1
diff changeset
    11
  PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">
1
25a17d01db0c Addition of the PDK content and example code for Documentation_content according to Feature bug 1607 and bug 1608
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    12
<concept xml:lang="en" id="GUID-C474376E-1766-5781-B5BF-3786C5B4D72E"><title>Performing Scalar Queries</title><prolog><metadata><keywords/></metadata></prolog><conbody><p>This tutorial describes the way in which you can execute scalar queries. </p> <section><title>Introduction</title> <p>A scalar query is a <codeph>SELECT</codeph> statement which refers to several data fields and returns a single result, for example, a <codeph>COUNT</codeph> query on a database column. This gives the number of records in the database. Symbian OS provides a class <xref href="GUID-E7B775B0-A609-313A-8BFD-375C81D782A5.dita"><apiname>TSqlScalarFullSelectQuery</apiname></xref>, for making scalar queries. This is more efficient than the <xref href="GUID-0176BF07-DF94-3259-8F90-DE030E35CE9A.dita"><apiname>RSqlStatement</apiname></xref> class. </p> </section> <section><title>Basic procedure</title> <p>The high level steps to perform scalar queries are shown here: </p> <ol id="GUID-55223195-5C72-5F61-A0E7-96B6EE3274F3"><li id="GUID-DCD1126E-F922-5D1F-84AE-DCEAD36005F4"><p>Declare the necessary variables. </p> </li> <li id="GUID-7218837C-3E0A-5B66-8814-234CB1DC5739"><p>Execute the query string. </p> </li> </ol> </section> <section><title>Detailed steps</title> <p>To make a scalar query, do the following: </p> <p><b>Declare the necessary variables</b> </p> <ol id="GUID-9B0B542F-F123-5933-8C54-A376EBD6C97F"><li id="GUID-6252DA75-22E2-5AB7-8F80-6C0EC52EEFD1"><p>Instantiate an object of the database class. </p> <codeblock id="GUID-2EA8226E-5867-59C2-B4D9-BEE0A2D1F730" xml:space="preserve">RSqlDatabase myDatabase;</codeblock> </li> <li id="GUID-95BB8C0A-4BCB-5F2F-AB02-4F30F9077CAB"><p>Declare a literal to hold the query string </p> <codeblock id="GUID-D76C33E4-9914-5D82-9CEB-0C94BFF0E0F4" xml:space="preserve">_LIT(kQueryString,"SELECT COUNT (*) FROM myTable");</codeblock> </li> <li id="GUID-2821B159-D8F7-5F8B-80D5-90A8EABE7D22"><p>Instantiate an object of the <xref href="GUID-E7B775B0-A609-313A-8BFD-375C81D782A5.dita"><apiname>TSqlScalarFullSelectQuery</apiname></xref> class. This class has a peculiar feature of instantiating an instance of it with a parameter that refers to the database to be queried. The class supplies a number of functions taking <codeph>SELECT</codeph> statements as parameters. </p> <codeblock id="GUID-FAF6DE03-B9CE-54B3-B58D-77BF47489E6E" xml:space="preserve">TSqlScalarFullSelectQuery myFullSelectQuery(myDatabase);</codeblock> </li> </ol> <p><b> Execute the query</b> </p>  </section> <section><title>See also</title> <p> <xref href="GUID-F36E5978-29FC-57E8-8A45-2003E7767193.dita">Querying a Database</xref>  </p> <p> <xref href="GUID-CCB9C61B-FB28-5CD9-A366-4A9584097897.dita">Inserting a Row into a Table</xref>  </p> <p> <xref href="GUID-3ACF6C11-A9CC-517C-8C7D-578F41F3DDF7.dita">Deleting Rows from a Table</xref>  </p> <p> <xref href="GUID-72511204-FC90-54AA-9E2E-833318020318.dita">Reading to a Buffer</xref>  </p> <p> <xref href="GUID-3CCA6503-54DA-5558-85DC-93A22A81F565.dita"> Reading to Memory </xref>  </p> <p> <xref href="GUID-183280EE-0C57-54FE-8ABB-E1CC3BDE525B.dita">Reading to a Data Stream</xref>  </p> <p> <xref href="GUID-B9A3B17E-BDEB-5F66-968C-080335A721AC.dita">Writing to a Data Stream</xref>  </p> <p>Performing Scalar Queries - This document </p> </section> </conbody></concept>