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