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40 lines
2.4 KiB
HTML
40 lines
2.4 KiB
HTML
<html><head><title>PgAccess Tutorial</title></head>
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<body bgcolor="#C0C0C0">
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<h1>PgAccess Tutorial - Editing a table</h1>
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<img src="sel_tbl.jpg" border=1 align=right>
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<h2>Adding records</h2>
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Once you have a table, you can begin to add entries to it. In the main
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PgAccess window, when you click the <em>Tables</em> button, you should see the
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new table appear in the list of tables. Highlighting the table name by clicking
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on it and clicking on the <em>Open</em> button will open that table in another
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window, as shown below.<p>
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The most straighforward way to add records to a table is to type the information
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directly into the fields. Two records have been entered in the table shown. As
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is common with this user interface, clicking the mouse while the pointer is in a
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field will allow keyboard entry to that field. This type of entry is adequate
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when the information arrives infrequently in small parcels, for instance in
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keeping a table of contact information about other researchers. However, what
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do you do when someone emails you the entire reference list for their doctoral
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dissertation?<p>
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This is best handled using the SQL <em>COPY</em> command.
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First, the information will have to be massaged into shape in what is called a
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'flat' ASCII file. This is simply a text file in which each line is a record,
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and each field in each record is separated by a <em>delimiter</em> such as a
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tilde (~). The fields will have to be in the same order as those in your table,
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and there will have to be the same number of fields in each record as are in the
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table, otherwise you may get unexpected data or no data at all. Say you produce
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a text file named <samp>newref.txt</samp> that starts like this:<p>
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<samp>Cassileth, BR~Unorthodox Cancer Medicine~Cancer Investigation~~1986~4~6~591-598
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<br>...</samp><p>
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Notice that there are two consecutive tildes to allow for the fact that this
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particular entry doesn't have anything in the <b>Editor</b> field.
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You can then perform a <em>Query</em> as follows:<p>
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<samp>COPY psyref FROM '/home/jim/newref.txt' USING DELIMITERS
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'~';</samp><p>
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This will read the records from <samp>newref.txt</samp> and insert them into the
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table <samp>psyref</samp>. See the PostgreSQL documentation under the headings
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<br><b>Tutorial|The Query Language|Populating a Class with Instances</b><p>
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<img src="addref.jpg" border=1 align=right>
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<a href="index.html#tut">Back to index</a>
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</body></html>
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