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Clean up pages. Add information for operator precedence.

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Split introduction sections into separate files to allow the legal notice
 and notation sections appear in all documents without having the history
 show up everplace too.
Add full list of reserved and non-reserved key words in syntax.sgml.
Add a separate chapter to the admin guide on security.
This commit is contained in:
Thomas G. Lockhart
1998-09-30 05:41:54 +00:00
parent d1a3b7528d
commit 2d73585028
23 changed files with 1812 additions and 727 deletions
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doc/src/sgml/oper.sgml
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@@ -29,6 +29,200 @@ oprleft|oprright|oprresult|oprcode
</ProgramListing>
</Para>
<sect1>
<title>Lexical Precedence</title>
<para>
Operators have a precedence which is currently hardcoded into the parser.
Most operators have the same precedence and are non-associative. This may lead
to non-intuitive behavior; for example the boolean operators "&lt;" and "&gt;"
have a different precedence that the boolean operators "&lt;=" and "&gt;=".
<table tocentry="1">
<title>
Operator Ordering (decreasing precedence)
</title>
<tgroup cols="2">
<thead>
<row>
<entry>
Element
<entry>
Precedence
<entry>
Description
</thead>
<tbody>
<row>
<entry>
UNION
<entry>
left
<entry>
SQL select construct
<row>
<entry>
::
<entry>
<entry>
<productname>Postgres</productname> typecasting
<row>
<entry>
[ ]
<entry>
left
<entry>
array delimiters
<row>
<entry>
.
<entry>
left
<entry>
table/column delimiter
<row>
<entry>
-
<entry>
right
<entry>
unary minus
<row>
<entry>
;
<entry>
left
<entry>
statement termination, logarithm
<row>
<entry>
:
<entry>
right
<entry>
exponentiation
<row>
<entry>
|
<entry>
left
<entry>
start of interval
<row>
<entry>
* /
<entry>
left
<entry>
multiplication, division
<row>
<entry>
+ -
<entry>
left
<entry>
addition, subtraction
<row>
<entry>
IS
<entry>
<entry>
test for TRUE, FALSE, NULL
<row>
<entry>
ISNULL
<entry>
<entry>
test for NULL
<row>
<entry>
NOTNULL
<entry>
<entry>
test for NOT NULL
<row>
<entry>
(all other operators)
<entry>
<entry>
native and user-defined
<row>
<entry>
IN
<entry>
<entry>
set membership
<row>
<entry>
BETWEEN
<entry>
<entry>
containment
<row>
<entry>
LIKE
<entry>
<entry>
string pattern matching
<row>
<entry>
&lt; &gt;
<entry>
<entry>
boolean inequality
<row>
<entry>
=
<entry>
right
<entry>
equality
<row>
<entry>
NOT
<entry>
right
<entry>
negation
<row>
<entry>
AND
<entry>
left
<entry>
logical intersection
<row>
<entry>
OR
<entry>
left
<entry>
logical union
</tbody>
</table>
<sect1>
<title>General Operators</title>