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@ -10,7 +10,7 @@ |
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alink="#0000ff"> |
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<H1>Frequently Asked Questions (FAQ) for PostgreSQL</H1> |
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<P>Last updated: Mon Jan 31 21:31:39 EST 2005</P> |
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<P>Last updated: Mon Jan 31 21:35:15 EST 2005</P> |
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<P>Current maintainer: Bruce Momjian (<A href= |
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"mailto:pgman@candle.pha.pa.us">pgman@candle.pha.pa.us</A>) |
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@ -1006,7 +1006,7 @@ length</TD></TR> |
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<P>Use <I>CURRENT_TIMESTAMP</I>:</P> |
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<PRE> |
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CREATE TABLE test (x int, modtime timestamp DEFAULT CURRENT_TIMESTAMP ); |
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CREATE TABLE test (x int, modtime TIMESTAMP DEFAULT CURRENT_TIMESTAMP ); |
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</PRE> |
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<H4><A name="4.17">4.17</A>) How do I perform an outer join?</H4> |
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@ -1032,23 +1032,6 @@ length</TD></TR> |
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<SMALL>RIGHT</SMALL>, and <SMALL>FULL</SMALL> joins. Ordinary joins |
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are called <SMALL>INNER</SMALL> joins.</P> |
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<P>In previous releases, outer joins can be simulated using |
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<SMALL>UNION</SMALL> and <SMALL>NOT IN</SMALL>. For example, when |
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joining <I>tab1</I> and <I>tab2</I>, the following query does an |
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<I>outer</I> join of the two tables:<BR> |
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<BR> |
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</P> |
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<PRE> |
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SELECT tab1.col1, tab2.col2 |
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FROM tab1, tab2 |
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WHERE tab1.col1 = tab2.col1 |
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UNION ALL |
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SELECT tab1.col1, NULL |
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FROM tab1 |
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WHERE tab1.col1 NOT IN (SELECT tab2.col1 FROM tab2) |
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ORDER BY col1 |
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</PRE> |
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<H4><A name="4.18">4.18</A>) How do I perform queries using |
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multiple databases?</H4> |
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