> Am Son, 2003-06-22 um 02.09 schrieb Joe Conway:

>>Sounds like all that's needed for your case. But to be complete, in
>>addition to changing tablefunc.c we'd have to:
>>1) come up with a new function call signature that makes sense and does
>>not cause backward compatibility problems for other people
>>2) make needed changes to tablefunc.sql.in
>>3) adjust the README.tablefunc appropriately
>>4) adjust the regression test for new functionality
>>5) be sure we don't break any of the old cases
>>
>>If you want to submit a complete patch, it would be gratefully accepted
>>-- for review at least ;-)
>
> Here's the patch, at least for steps 1-3

Nabil Sayegh
Joe Conway

contrib/tablefunc/README.tablefunc

@@ -4,6 +4,8 @@
  * Sample to demonstrate C functions which return setof scalar
  * and setof composite.
  * Joe Conway <mail@joeconway.com>
+ * And contributors:
+ * Nabil Sayegh <postgresql@e-trolley.de>
  *
  * Copyright 2002 by PostgreSQL Global Development Group
  *
@@ -60,9 +62,11 @@ Installation:
       - requires anonymous composite type syntax in the FROM clause. See
         the instructions in the documentation below.
 
-    connectby(text relname, text keyid_fld, text parent_keyid_fld,
-                text start_with, int max_depth [, text branch_delim])
+    connectby(text relname, text keyid_fld, text parent_keyid_fld
+                [, text orderby_fld], text start_with, int max_depth
+								[, text branch_delim])
       - returns keyid, parent_keyid, level, and an optional branch string
+        and an optional serial column for ordering siblings
       - requires anonymous composite type syntax in the FROM clause. See
         the instructions in the documentation below.
 
@@ -452,13 +456,14 @@ AS
 ==================================================================
 Name
 
-connectby(text, text, text, text, int[, text]) - returns a set
+connectby(text, text, text[, text], text, text, int[, text]) - returns a set
     representing a hierarchy (tree structure)
 
 Synopsis
 
-connectby(text relname, text keyid_fld, text parent_keyid_fld,
-            text start_with, int max_depth [, text branch_delim])
+connectby(text relname, text keyid_fld, text parent_keyid_fld
+            [, text orderby_fld], text start_with, int max_depth
+						[, text branch_delim])
 
 Inputs
 
@@ -474,6 +479,11 @@ Inputs
 
     Name of the key_parent field
 
+  orderby_fld
+
+    If optional ordering of siblings is desired:
+    Name of the field to order siblings
+
   start_with
 
     root value of the tree input as a text value regardless of keyid_fld type
@@ -500,6 +510,16 @@ Outputs
 
     SELECT * FROM connectby('connectby_tree', 'keyid', 'parent_keyid', 'row2', 0)
       AS t(keyid text, parent_keyid text, level int);
+			
+		- or -
+
+    SELECT * FROM connectby('connectby_tree', 'keyid', 'parent_keyid', 'pos', 'row2', 0, '~')
+      AS t(keyid text, parent_keyid text, level int, branch text, pos int);
+
+		- or -
+
+    SELECT * FROM connectby('connectby_tree', 'keyid', 'parent_keyid', 'pos', 'row2', 0)
+      AS t(keyid text, parent_keyid text, level int, pos int);
     
 Notes
 
@@ -520,22 +540,25 @@ Notes
   5. The parameters representing table and field names must include double
      quotes if the names are mixed-case or contain special characters.
 
+  6. If sorting of siblings is desired, the orderby_fld input parameter *and*
+     a name for the resulting serial field (type INT32) in the query column
+     definition must be given.
 
 Example usage
 
-CREATE TABLE connectby_tree(keyid text, parent_keyid text);
+CREATE TABLE connectby_tree(keyid text, parent_keyid text, pos int);
 
-INSERT INTO connectby_tree VALUES('row1',NULL);
-INSERT INTO connectby_tree VALUES('row2','row1');
-INSERT INTO connectby_tree VALUES('row3','row1');
-INSERT INTO connectby_tree VALUES('row4','row2');
-INSERT INTO connectby_tree VALUES('row5','row2');
-INSERT INTO connectby_tree VALUES('row6','row4');
-INSERT INTO connectby_tree VALUES('row7','row3');
-INSERT INTO connectby_tree VALUES('row8','row6');
-INSERT INTO connectby_tree VALUES('row9','row5');
+INSERT INTO connectby_tree VALUES('row1',NULL, 0);
+INSERT INTO connectby_tree VALUES('row2','row1', 0);
+INSERT INTO connectby_tree VALUES('row3','row1', 0);
+INSERT INTO connectby_tree VALUES('row4','row2', 1);
+INSERT INTO connectby_tree VALUES('row5','row2', 0);
+INSERT INTO connectby_tree VALUES('row6','row4', 0);
+INSERT INTO connectby_tree VALUES('row7','row3', 0);
+INSERT INTO connectby_tree VALUES('row8','row6', 0);
+INSERT INTO connectby_tree VALUES('row9','row5', 0);
 
--- with branch
+-- with branch, without orderby_fld
 SELECT * FROM connectby('connectby_tree', 'keyid', 'parent_keyid', 'row2', 0, '~')
  AS t(keyid text, parent_keyid text, level int, branch text);
  keyid | parent_keyid | level |       branch
@@ -548,7 +571,7 @@ SELECT * FROM connectby('connectby_tree', 'keyid', 'parent_keyid', 'row2', 0, '~
  row9  | row5         |     2 | row2~row5~row9
 (6 rows)
 
--- without branch
+-- without branch, without orderby_fld
 SELECT * FROM connectby('connectby_tree', 'keyid', 'parent_keyid', 'row2', 0)
  AS t(keyid text, parent_keyid text, level int);
  keyid | parent_keyid | level
@@ -561,6 +584,32 @@ SELECT * FROM connectby('connectby_tree', 'keyid', 'parent_keyid', 'row2', 0)
  row9  | row5         |     2
 (6 rows)
 
+-- with branch, with orderby_fld (notice that row5 comes before row4)
+SELECT * FROM connectby('connectby_tree', 'keyid', 'parent_keyid', 'pos', 'row2', 0, '~')
+ AS t(keyid text, parent_keyid text, level int, branch text, pos int) ORDER BY t.pos;
+ keyid | parent_keyid | level |       branch        | pos 
+-------+--------------+-------+---------------------+-----
+ row2  |              |     0 | row2                |   1
+ row5  | row2         |     1 | row2~row5           |   2
+ row9  | row5         |     2 | row2~row5~row9      |   3
+ row4  | row2         |     1 | row2~row4           |   4
+ row6  | row4         |     2 | row2~row4~row6      |   5
+ row8  | row6         |     3 | row2~row4~row6~row8 |   6
+(6 rows)
+
+-- without branch, with orderby_fld (notice that row5 comes before row4)
+SELECT * FROM connectby('connectby_tree', 'keyid', 'parent_keyid', 'pos', 'row2', 0)
+ AS t(keyid text, parent_keyid text, level int, pos int) ORDER BY t.pos;
+ keyid | parent_keyid | level | pos
+-------+--------------+-------+-----
+ row2  |              |     0 |   1
+ row5  | row2         |     1 |   2
+ row9  | row5         |     2 |   3
+ row4  | row2         |     1 |   4
+ row6  | row4         |     2 |   5
+ row8  | row6         |     3 |   6
+(6 rows)
+
 ==================================================================
 -- Joe Conway
 

contrib/tablefunc/data/connectby_text.data

-row1	\N
-row2	row1
-row3	row1
-row4	row2
-row5	row2
-row6	row4
-row7	row3
-row8	row6
-row9	row5
+row1	\N	0
+row2	row1	0
+row3	row1	0
+row4	row2	1
+row5	row2	0
+row6	row4	0
+row7	row3	0
+row8	row6	0
+row9	row5	0

contrib/tablefunc/expected/tablefunc.out

@@ -197,9 +197,9 @@ ERROR:  provided "categories" SQL must return 1 column of at least one row
 -- connectby
 --
 -- test connectby with text based hierarchy
-CREATE TABLE connectby_text(keyid text, parent_keyid text);
+CREATE TABLE connectby_text(keyid text, parent_keyid text, pos int);
 \copy connectby_text from 'data/connectby_text.data'
--- with branch
+-- with branch, without orderby
 SELECT * FROM connectby('connectby_text', 'keyid', 'parent_keyid', 'row2', 0, '~') AS t(keyid text, parent_keyid text, level int, branch text);
  keyid | parent_keyid | level |       branch        
 -------+--------------+-------+---------------------
@@ -211,7 +211,7 @@ SELECT * FROM connectby('connectby_text', 'keyid', 'parent_keyid', 'row2', 0, '~
  row9  | row5         |     2 | row2~row5~row9
 (6 rows)
 
--- without branch
+-- without branch, without orderby
 SELECT * FROM connectby('connectby_text', 'keyid', 'parent_keyid', 'row2', 0) AS t(keyid text, parent_keyid text, level int);
  keyid | parent_keyid | level 
 -------+--------------+-------
@@ -223,6 +223,30 @@ SELECT * FROM connectby('connectby_text', 'keyid', 'parent_keyid', 'row2', 0) AS
  row9  | row5         |     2
 (6 rows)
 
+-- with branch, with orderby
+SELECT * FROM connectby('connectby_text', 'keyid', 'parent_keyid', 'pos', 'row2', 0, '~') AS t(keyid text, parent_keyid text, level int, branch text, pos int) ORDER BY t.pos;
+ keyid | parent_keyid | level |       branch        | pos 
+-------+--------------+-------+---------------------+-----
+ row2  |              |     0 | row2                |   1
+ row5  | row2         |     1 | row2~row5           |   2
+ row9  | row5         |     2 | row2~row5~row9      |   3
+ row4  | row2         |     1 | row2~row4           |   4
+ row6  | row4         |     2 | row2~row4~row6      |   5
+ row8  | row6         |     3 | row2~row4~row6~row8 |   6
+(6 rows)
+
+-- without branch, with orderby
+SELECT * FROM connectby('connectby_text', 'keyid', 'parent_keyid', 'pos', 'row2', 0) AS t(keyid text, parent_keyid text, level int, pos int) ORDER BY t.pos;
+ keyid | parent_keyid | level | pos 
+-------+--------------+-------+-----
+ row2  |              |     0 |   1
+ row5  | row2         |     1 |   2
+ row9  | row5         |     2 |   3
+ row4  | row2         |     1 |   4
+ row6  | row4         |     2 |   5
+ row8  | row6         |     3 |   6
+(6 rows)
+
 -- test connectby with int based hierarchy
 CREATE TABLE connectby_int(keyid int, parent_keyid int);
 \copy connectby_int from 'data/connectby_int.data'

contrib/tablefunc/sql/tablefunc.sql

@@ -94,15 +94,21 @@ AS c(rowid text, rowdt timestamp, temperature int4, test_result text, test_start
 --
 
 -- test connectby with text based hierarchy
-CREATE TABLE connectby_text(keyid text, parent_keyid text);
+CREATE TABLE connectby_text(keyid text, parent_keyid text, pos int);
 \copy connectby_text from 'data/connectby_text.data'
 
--- with branch
+-- with branch, without orderby
 SELECT * FROM connectby('connectby_text', 'keyid', 'parent_keyid', 'row2', 0, '~') AS t(keyid text, parent_keyid text, level int, branch text);
 
--- without branch
+-- without branch, without orderby
 SELECT * FROM connectby('connectby_text', 'keyid', 'parent_keyid', 'row2', 0) AS t(keyid text, parent_keyid text, level int);
 
+-- with branch, with orderby
+SELECT * FROM connectby('connectby_text', 'keyid', 'parent_keyid', 'pos', 'row2', 0, '~') AS t(keyid text, parent_keyid text, level int, branch text, pos int) ORDER BY t.pos;
+
+-- without branch, with orderby
+SELECT * FROM connectby('connectby_text', 'keyid', 'parent_keyid', 'pos', 'row2', 0) AS t(keyid text, parent_keyid text, level int, pos int) ORDER BY t.pos;
+
 -- test connectby with int based hierarchy
 CREATE TABLE connectby_int(keyid int, parent_keyid int);
 \copy connectby_int from 'data/connectby_int.data'

contrib/tablefunc/tablefunc.h

@@ -4,6 +4,8 @@
  * Sample to demonstrate C functions which return setof scalar
  * and setof composite.
  * Joe Conway <mail@joeconway.com>
+ * And contributors:
+ * Nabil Sayegh <postgresql@e-trolley.de>
  *
  * Copyright 2002 by PostgreSQL Global Development Group
  *
@@ -36,5 +38,6 @@ extern Datum normal_rand(PG_FUNCTION_ARGS);
 extern Datum crosstab(PG_FUNCTION_ARGS);
 extern Datum crosstab_hash(PG_FUNCTION_ARGS);
 extern Datum connectby_text(PG_FUNCTION_ARGS);
+extern Datum connectby_text_serial(PG_FUNCTION_ARGS);
 
 #endif   /* TABLEFUNC_H */

contrib/tablefunc/tablefunc.sql.in

@@ -64,3 +64,15 @@ CREATE OR REPLACE FUNCTION connectby(text,text,text,text,int)
 RETURNS setof record
 AS 'MODULE_PATHNAME','connectby_text'
 LANGUAGE 'C' STABLE STRICT;
+
+-- These 2 take the name of a field to ORDER BY as 4th arg (for sorting siblings)
+
+CREATE OR REPLACE FUNCTION connectby(text,text,text,text,text,int,text)
+RETURNS setof record
+AS 'MODULE_PATHNAME','connectby_text_serial'
+LANGUAGE 'C' STABLE STRICT;
+
+CREATE OR REPLACE FUNCTION connectby(text,text,text,text,text,int)
+RETURNS setof record
+AS 'MODULE_PATHNAME','connectby_text_serial'
+LANGUAGE 'C' STABLE STRICT;