david
2a98435b14
git-svn-id: https://192.168.0.254/svn/Componentes.Terceros.RemObjects@68 b6239004-a887-0f4b-9937-50029ccdca16
52 lines
2.0 KiB
HTML
52 lines
2.0 KiB
HTML
<html>
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<head>
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<link rel="stylesheet" type="text/css" href="..\styles.css">
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</head>
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<body>
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<img src="..\..\da.png" alt="" align="right">
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<!-------------------------------------------------------------------------->
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<p class="h1">Union Tables Sample</p>
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<p>
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This sample uses <b>Unions</b> defined in the server's Schema to fetch data from several tables in the back-end
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database that is seamlessly combined and available to the client as a unified data table.
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Note how the Union table contains an additional @SourceTable field to indicate the original table,
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and how by filling the @SourceTable field with the appropriate value when inserting new records,
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those records can automatically be updated into the appropriate back-end table.
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</p>
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<p class="h2">Examine the code</p>
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<ul>
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<li>
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Take a look at the <b>TClientForm.btLoadClick</b> method to see how the data is loaded.
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Note that the calculated field SourceTableName is not loaded from the server.
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</li>
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<li>See the <b>TClientForm.btUpdateClick</b> event handler, where the dataset is updated.</li>
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<li>
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Look at the piece of code in <b>TClientForm.btUpdateClick</b> method related to filter.
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See how <b>Dynamic Where</b> conditions are applied to the <b>Union Tables</b>.
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<b>Dynamic Where</b> conditions work fine against union tables.
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</li>
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<li>
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Examine properties of the <b>RemoteDataAdapter</b>.
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Note that its <b>DataStreamer.SendReducedDelta</b> and <b>DynamicSelect</b> properties are both set to true.
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</li>
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</ul>
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<p class="h2">Getting started</p>
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<ul>
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<li>Run the Sample Server.</li>
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<li>Run the Union Tables Sample.</li>
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<li>Try to fill DataSet.</li>
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<li>Try to change some records.</li>
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<li>Apply changes to the server using the Update button.</li>
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<li>Examine the Sql command used to load and update data (in the server log).</li>
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<li>
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Try to apply simple DynamicWhere condition like 'fr'. Examine the server log to see how the data is loaded from two
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different physical tables using the provided condition.
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</li>
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</ul>
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</body>
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</html> |