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<concept id="GUID-118C8F84-2BB3-5F60-B6AB-22F0F1B3349E" xml:lang="en"><title>Types

of rowset</title><shortdesc>Describes the types of rowset available to you.</shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>

<p>Database application programs use a <keyword>rowset</keyword>, which maintains

a <keyword>cursor</keyword> on a current row within that set. The rowset provides

an abstract interface, two types are provided:</p>

<ul>

<li id="GUID-87C3A645-D3F9-5D16-8B4C-CA3FE80AA7D3"><p>a table is an entire

table in a database. Row ordering is either undefined, or by one of the table’s

indexes. Fast key-based retrieval using an index can be performed on a table.

The table is encapsulated in the derived class <codeph>RDbTable</codeph>.</p> </li>

<li id="GUID-BC628D8C-BCC4-50AF-B1E3-93428CDB8506"><p>an SQL view is a rowset

generated by an <keyword>SQL</keyword> query on a database, currently restricted

to a single table. Cursor navigation is implemented by evaluating the view

as necessary. Since evaluation may be expensive, a pre-evaluation window may

be specified, allowing the rowset to be evaluated once and navigated quickly.

The desired window is described by the <codeph>TDbWindow</codeph> class. Rowsets

can also be evaluated in steps. The SQL view is encapsulated in the derived

class <codeph>RDbView</codeph>. </p> </li>

</ul>

</conbody></concept>