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Merge documentation updates from 7.3 branch.

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This commit is contained in:
Peter Eisentraut
2002-11-11 20:14:04 +00:00
parent b327906683
commit 1b342df00a
28 changed files with 2330 additions and 2479 deletions
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doc/src/sgml/array.sgml
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@@ -1,4 +1,4 @@
<!-- $Header: /cvsroot/pgsql/doc/src/sgml/array.sgml,v 1.23 2002/11/10 00:32:16 momjian Exp $ -->
<!-- $Header: /cvsroot/pgsql/doc/src/sgml/array.sgml,v 1.24 2002/11/11 20:14:02 petere Exp $ -->
<sect1 id="arrays">
<title>Arrays</title>
@@ -21,7 +21,7 @@ CREATE TABLE sal_emp (
</programlisting>
As shown, an array data type is named by appending square brackets
(<literal>[]</>) to the data type name of the array elements.
The above query will create a table named
The above command will create a table named
<structname>sal_emp</structname> with columns including
a <type>text</type> string (<structfield>name</structfield>),
a one-dimensional array of type
@@ -68,7 +68,7 @@ SELECT name FROM sal_emp WHERE pay_by_quarter[1] &lt;&gt; pay_by_quarter[2];
The array subscript numbers are written within square brackets.
By default <productname>PostgreSQL</productname> uses the
<quote>one-based</quote> numbering convention for arrays, that is,
one-based numbering convention for arrays, that is,
an array of <replaceable>n</> elements starts with <literal>array[1]</literal> and
ends with <literal>array[<replaceable>n</>]</literal>.
</para>
@@ -90,10 +90,9 @@ SELECT pay_by_quarter[3] FROM sal_emp;
<para>
We can also access arbitrary rectangular slices of an array, or
subarrays. An array slice is denoted by writing
<literal><replaceable>lower subscript</replaceable> :
<replaceable>upper subscript</replaceable></literal> for one or more
array dimensions. This query retrieves the first item on Bill's
schedule for the first two days of the week:
<literal><replaceable>lower-bound</replaceable>:<replaceable>upper-bound</replaceable></literal>
for one or more array dimensions. This query retrieves the first
item on Bill's schedule for the first two days of the week:
<programlisting>
SELECT schedule[1:2][1:1] FROM sal_emp WHERE name = 'Bill';
@@ -112,9 +111,10 @@ SELECT schedule[1:2][1] FROM sal_emp WHERE name = 'Bill';
with the same result. An array subscripting operation is taken to
represent an array slice if any of the subscripts are written in the
form <replaceable>lower</replaceable> <literal>:</literal>
<replaceable>upper</replaceable>. A lower bound of 1 is assumed for
any subscript where only one value is specified.
form
<literal><replaceable>lower</replaceable>:<replaceable>upper</replaceable></literal>.
A lower bound of 1 is assumed for any subscript where only one value
is specified.
</para>
<para>
@@ -310,7 +310,7 @@ SELECT * FROM sal_emp WHERE pay_by_quarter **= 10000;
<tip>
<para>
Remember that what you write in an SQL query will first be interpreted
Remember that what you write in an SQL command will first be interpreted
as a string literal, and then as an array. This doubles the number of
backslashes you need. For example, to insert a <type>text</> array
value containing a backslash and a double quote, you'd need to write
@@ -323,7 +323,7 @@ INSERT ... VALUES ('{"\\\\","\\""}');
become <literal>\</> and <literal>"</> respectively. (If we were working
with a data type whose input routine also treated backslashes specially,
<type>bytea</> for example, we might need as many as eight backslashes
in the query to get one backslash into the stored array element.)
in the command to get one backslash into the stored array element.)
</para>
</tip>