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Commit432fb5b

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Updates for array documentation, from Joe Conway.
1 parent80860c3 commit432fb5b

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3 files changed

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3 files changed

+85
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‎doc/src/sgml/array.sgml‎

Lines changed: 58 additions & 18 deletions
Original file line numberDiff line numberDiff line change
@@ -1,4 +1,4 @@
1-
<!-- $Header: /cvsroot/pgsql/doc/src/sgml/array.sgml,v 1.29 2003/08/09 22:50:21 tgl Exp $ -->
1+
<!-- $Header: /cvsroot/pgsql/doc/src/sgml/array.sgml,v 1.30 2003/08/19 06:06:43 tgl Exp $ -->
22

33
<sect1 id="arrays">
44
<title>Arrays</title>
@@ -162,7 +162,6 @@ ERROR: multidimensional arrays must have array expressions with matching dimens
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expression syntax is discussed in more detail in <xref
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linkend="sql-syntax-array-constructors">.
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</para>
165-
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</sect2>
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168167
<sect2>
@@ -326,9 +325,9 @@ UPDATE sal_emp SET pay_by_quarter[1:2] = '{27000,27000}'
326325
<literal>||</literal>.
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<programlisting>
328327
SELECT ARRAY[1,2] || ARRAY[3,4];
329-
?column?
330-
---------------
331-
{{1,2},{3,4}}
328+
?column?
329+
-----------
330+
{1,2,3,4}
332331
(1 row)
333332

334333
SELECT ARRAY[5,6] || ARRAY[[1,2],[3,4]];
@@ -337,27 +336,68 @@ SELECT ARRAY[5,6] || ARRAY[[1,2],[3,4]];
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{{5,6},{1,2},{3,4}}
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(1 row)
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</programlisting>
339+
</para>
340340

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<para>
341342
The concatenation operator allows a single element to be pushed on to the
342343
beginning or end of a one-dimensional array. It also accepts two
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<replaceable>N</>-dimensional arrays, or an <replaceable>N</>-dimensional
344-
and an <replaceable>N+1</>-dimensional array. In the former case, the two
345-
<replaceable>N</>-dimension arrays become outer elements of an
346-
<replaceable>N+1</>-dimensional array. In the latter, the
347-
<replaceable>N</>-dimensional array is added as either the first or last
348-
outer element of the <replaceable>N+1</>-dimensional array.
349-
350-
When extending an array by concatenation, the subscripts of its existing
351-
elements are preserved. For example, when pushing
352-
onto the beginning of an array with one-based subscripts, the resulting
353-
array has zero-based subscripts:
345+
and an <replaceable>N+1</>-dimensional array.
346+
</para>
354347

348+
<para>
349+
When a single element is pushed on to the beginning of a one-dimensional
350+
array, the result is an array with a lower bound subscript equal to
351+
the righthand operand's lower bound subscript, minus one. When a single
352+
element is pushed on to the end of a one-dimensional array, the result is
353+
an array retaining the lower bound of the lefthand operand. For example:
355354
<programlisting>
356355
SELECT array_dims(1 || ARRAY[2,3]);
357356
array_dims
358357
------------
359358
[0:2]
360359
(1 row)
360+
361+
SELECT array_dims(ARRAY[1,2] || 3);
362+
array_dims
363+
------------
364+
[1:3]
365+
(1 row)
366+
</programlisting>
367+
</para>
368+
369+
<para>
370+
When two arrays with an equal number of dimensions are concatenated, the
371+
result retains the lower bound subscript of the lefthand operand's outer
372+
dimension. The result is an array comprising every element of the lefthand
373+
operand followed by every element of the righthand operand. For example:
374+
<programlisting>
375+
SELECT array_dims(ARRAY[1,2] || ARRAY[3,4,5]);
376+
array_dims
377+
------------
378+
[1:5]
379+
(1 row)
380+
381+
SELECT array_dims(ARRAY[[1,2],[3,4]] || ARRAY[[5,6],[7,8],[9,0]]);
382+
array_dims
383+
------------
384+
[1:5][1:2]
385+
(1 row)
386+
</programlisting>
387+
</para>
388+
389+
<para>
390+
When an <replaceable>N</>-dimensional array is pushed on to the beginning
391+
or end of an <replaceable>N+1</>-dimensional array, the result is
392+
analogous to the element-array case above. Each <replaceable>N</>-dimensional
393+
sub-array is essentially an element of the <replaceable>N+1</>-dimensional
394+
array's outer dimension. For example:
395+
<programlisting>
396+
SELECT array_dims(ARRAY[1,2] || ARRAY[[3,4],[5,6]]);
397+
array_dims
398+
------------
399+
[0:2][1:2]
400+
(1 row)
361401
</programlisting>
362402
</para>
363403

@@ -386,9 +426,9 @@ SELECT array_append(ARRAY[1,2], 3);
386426
(1 row)
387427

388428
SELECT array_cat(ARRAY[1,2], ARRAY[3,4]);
389-
array_cat
390-
---------------
391-
{{1,2},{3,4}}
429+
array_cat
430+
-----------
431+
{1,2,3,4}
392432
(1 row)
393433

394434
SELECT array_cat(ARRAY[[1,2],[3,4]], ARRAY[5,6]);

‎doc/src/sgml/func.sgml‎

Lines changed: 9 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -1,5 +1,5 @@
11
<!--
2-
$Header: /cvsroot/pgsql/doc/src/sgml/func.sgml,v 1.167 2003/08/17 04:52:41 momjian Exp $
2+
$Header: /cvsroot/pgsql/doc/src/sgml/func.sgml,v 1.168 2003/08/19 06:06:43 tgl Exp $
33
PostgreSQL documentation
44
-->
55

@@ -7032,7 +7032,7 @@ SELECT pg_type_is_visible('myschema.widget'::regtype);
70327032

70337033
<para>
70347034
<xref linkend="array-operators-table"> shows the operators
7035-
available forthe<type>array</type> types.
7035+
available for <type>array</type> types.
70367036
</para>
70377037

70387038
<table id="array-operators-table">
@@ -7093,7 +7093,7 @@ SELECT pg_type_is_visible('myschema.widget'::regtype);
70937093
<entry> <literal>||</literal> </entry>
70947094
<entry>array-to-array concatenation</entry>
70957095
<entry><literal>ARRAY[1,2,3] || ARRAY[4,5,6]</literal></entry>
7096-
<entry><literal>{{1,2,3},{4,5,6}}</literal></entry>
7096+
<entry><literal>{1,2,3,4,5,6}</literal></entry>
70977097
</row>
70987098

70997099
<row>
@@ -7120,6 +7120,11 @@ SELECT pg_type_is_visible('myschema.widget'::regtype);
71207120
</tgroup>
71217121
</table>
71227122

7123+
<para>
7124+
See <xref linkend="arrays"> for more details about array operator
7125+
behavior.
7126+
</para>
7127+
71237128
<para>
71247129
<xref linkend="array-functions-table"> shows the functions
71257130
available for use with array types. See <xref linkend="arrays">
@@ -7167,7 +7172,7 @@ SELECT pg_type_is_visible('myschema.widget'::regtype);
71677172
for <literal>NULL</literal> inputs
71687173
</entry>
71697174
<entry><literal>array_cat(ARRAY[1,2,3], ARRAY[4,5,6])</literal></entry>
7170-
<entry><literal>{{1,2,3},{4,5,6}}</literal></entry>
7175+
<entry><literal>{1,2,3,4,5,6}</literal></entry>
71717176
</row>
71727177
<row>
71737178
<entry>

‎doc/src/sgml/syntax.sgml‎

Lines changed: 18 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -1,5 +1,5 @@
11
<!--
2-
$Header: /cvsroot/pgsql/doc/src/sgml/syntax.sgml,v 1.82 2003/08/14 23:13:27 tgl Exp $
2+
$Header: /cvsroot/pgsql/doc/src/sgml/syntax.sgml,v 1.83 2003/08/19 06:06:48 tgl Exp $
33
-->
44

55
<chapter id="sql-syntax">
@@ -1270,6 +1270,23 @@ SELECT ARRAY[[1,2],[3,4]];
12701270
at the same level must produce sub-arrays of identical dimensions.
12711271
</para>
12721272

1273+
<para>
1274+
Multidimensional array constructor elements can be anything yielding
1275+
an array of the proper kind, not only a sub-<literal>ARRAY</> construct.
1276+
For example:
1277+
<programlisting>
1278+
create table arr(f1 int[], f2 int[]);
1279+
CREATE TABLE
1280+
insert into arr values (ARRAY[[1,2],[3,4]],ARRAY[[5,6],[7,8]]);
1281+
INSERT 2635544 1
1282+
select ARRAY[f1, f2, '{{9,10},{11,12}}'::int[]] from arr;
1283+
array
1284+
------------------------------------------------
1285+
{{{1,2},{3,4}},{{5,6},{7,8}},{{9,10},{11,12}}}
1286+
(1 row)
1287+
</programlisting>
1288+
</para>
1289+
12731290
<para>
12741291
It is also possible to construct an array from the results of a
12751292
subquery. In this form, the array constructor is written with the

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