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Terminology cleanup: class -> table, instance -> row, attribute -> column,

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etc.
This commit is contained in:
Peter Eisentraut
2001-01-13 23:58:55 +00:00
parent 0651a5799d
commit 027f144e39
38 changed files with 300 additions and 323 deletions
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64
doc/src/sgml/syntax.sgml
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@@ -1,5 +1,5 @@
<!--
$Header: /cvsroot/pgsql/doc/src/sgml/syntax.sgml,v 1.34 2001/01/13 18:34:51 petere Exp $
$Header: /cvsroot/pgsql/doc/src/sgml/syntax.sgml,v 1.35 2001/01/13 23:58:55 petere Exp $
-->
<chapter id="sql-syntax">
@@ -553,15 +553,12 @@ CAST ( '<replaceable>string</replaceable>' AS <replaceable>type</replaceable> )
<sect1 id="sql-syntax-columns">
<title>Fields and Columns</title>
<sect2>
<title>Fields</title>
<title>Columns</title>
<para>
A <firstterm>field</firstterm>
is either a user-defined attribute of a given class or one of the
following system-defined attributes:
A <firstterm>column</firstterm>
is either a user-defined column of a given table or one of the
following system-defined columns:
<variablelist>
<varlistentry>
@@ -653,40 +650,29 @@ CAST ( '<replaceable>string</replaceable>' AS <replaceable>type</replaceable> )
<xref linkend="STON87a" endterm="STON87a">.
Transaction and command identifiers are 32 bit quantities.
</para>
</sect2>
<sect2>
<title>Columns</title>
<para>
A <firstterm>column</firstterm> is a construct of the form:
A column can be referenced in the form:
<synopsis>
<replaceable>instance</replaceable>{.<replaceable>composite_field</replaceable>}.<replaceable>field</replaceable> `['<replaceable>subscript</replaceable>`]'
</synopsis>
<synopsis>
<replaceable>corelation</replaceable>.<replaceable>columnname</replaceable> `['<replaceable>subscript</replaceable>`]'
</synopsis>
<replaceable>instance</replaceable>
identifies a particular class and can be thought of as standing for
the instances of that class. An instance variable is either a class
name, an alias for a class defined by means of a FROM clause,
or the keyword NEW or OLD.
(NEW and OLD can only appear in the action portion of a rule, while
other instance variables can be used in any SQL statement.) The
instance name can be omitted if the first field name is unique
across all the classes being used in the current query.
<replaceable>composite_field</replaceable>
is a field of of one of the Postgres composite types,
while successive composite fields select attributes in the
class(s) to which the composite field evaluates. Lastly,
<replaceable>field</replaceable>
is a normal (base type) field in the class(s) last addressed. If
<replaceable>field</replaceable>
is of an array type,
then the optional <replaceable>subscript</replaceable>
selects a specific element in the array. If no subscript is
provided, then the whole array is selected.
<replaceable>corelation</replaceable> is either the name of a
table, an alias for a table defined by means of a FROM clause, or
the keyword <literal>NEW</literal> or <literal>OLD</literal>.
(NEW and OLD can only appear in the action portion of a rule,
while other corelation names can be used in any SQL statement.)
The corelation name can be omitted if the column name is unique
across all the tables being used in the current query. If
<replaceable>column</replaceable> is of an array type, then the
optional <replaceable>subscript</replaceable> selects a specific
element in the array. If no subscript is provided, then the
whole array is selected. Refer to the description of the
particular commands in the <citetitle>PostgreSQL Reference
Manual</citetitle> for the allowed syntax in each case.
</para>
</sect2>
</sect1>
<sect1 id="sql-expressions">
@@ -861,10 +847,10 @@ sqrt(emp.salary)
The simplest possibility for a from-expression is:
<synopsis>
<replaceable>class_reference</replaceable> [ [ AS ] <replaceable class="PARAMETER">alias</replaceable> ]
<replaceable>table_reference</replaceable> [ [ AS ] <replaceable class="PARAMETER">alias</replaceable> ]
</synopsis>
where <replaceable>class_reference</replaceable> is of the form
where <replaceable>table_reference</replaceable> is of the form
<synopsis>
[ ONLY ] <replaceable class="PARAMETER">table_name</replaceable> [ * ]