Re: TODO item: Have psql show current values for a sequence - Mailing list pgsql-hackers

Wow.  I adjusted the patch slightly and applied it;  the updated version
is attached.  We have been waiting for this to be done for quite some
time.  Thanks.

---------------------------------------------------------------------------


Dickson S. Guedes wrote:
> Hi all,
>
> These patch implements the TODO item: Have psql show current values
> for a sequence.
> Comments are welcome.
>
> * Credits
>
> The original patch were developed by Euler Taveira de Oliveira
> <euler@timbira.com>
> but how he is a little busy, he sends it to me and I made some changes
> to satisfy
> the TODO item above.
>
> * Discussions
>
> http://archives.postgresql.org/pgsql-hackers/2007-12/msg00102.php
> http://archives.postgresql.org/pgsql-hackers/2007-12/msg00605.php
>
> * Outputs
>
> # \d foo_bar_seq
>           Sequence "public.foo_bar_seq"
> +---------------+---------+---------------------+
> |    Column     |  Type   |        Value        |
> +---------------+---------+---------------------+
> | sequence_name | name    | foo_bar_seq         |
> | last_value    | bigint  | 11                  |
> | start_value   | bigint  | 1                   |
> | increment_by  | bigint  | 1                   |
> | max_value     | bigint  | 9223372036854775807 |
> | min_value     | bigint  | 1                   |
> | cache_value   | bigint  | 1                   |
> | log_cnt       | bigint  | 31                  |
> | is_cycled     | boolean | f                   |
> | is_called     | boolean | t                   |
> +---------------+---------+---------------------+
>
> # \d+ foo_bar_seq
>                  Sequence "public.foo_bar_seq"
> +---------------+---------+---------------------+-------------+
> |    Column     |  Type   |        Value        | Description |
> +---------------+---------+---------------------+-------------+
> | sequence_name | name    | foo_bar_seq         |             |
> | last_value    | bigint  | 11                  |             |
> | start_value   | bigint  | 1                   |             |
> | increment_by  | bigint  | 1                   |             |
> | max_value     | bigint  | 9223372036854775807 |             |
> | min_value     | bigint  | 1                   |             |
> | cache_value   | bigint  | 1                   |             |
> | log_cnt       | bigint  | 31                  |             |
> | is_cycled     | boolean | f                   |             |
> | is_called     | boolean | t                   |             |
> +---------------+---------+---------------------+-------------+
>
> --
> []s
> Dickson S. Guedes
> --------------------------------------
> Projeto Colmeia - Curitiba - PR
> +55 (41) 3254-7130 ramal: 27
> http://makeall.wordpress.com/
> http://pgcon.postgresql.org.br/
> http://planeta.postgresql.org.br/

[ Attachment, skipping... ]

>
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--
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

  + If your life is a hard drive, Christ can be your backup. +
Index: src/bin/psql/describe.c
===================================================================
RCS file: /cvsroot/pgsql/src/bin/psql/describe.c,v
retrieving revision 1.179
diff -c -c -r1.179 describe.c
*** src/bin/psql/describe.c    14 Jul 2008 23:13:04 -0000    1.179
--- src/bin/psql/describe.c    15 Jul 2008 03:06:24 -0000
***************
*** 811,817 ****
      printTableContent cont;
      int            i;
      char       *view_def = NULL;
!     char       *headers[5];
      char      **modifiers = NULL;
      char      **ptr;
      PQExpBufferData title;
--- 811,818 ----
      printTableContent cont;
      int            i;
      char       *view_def = NULL;
!     char       *headers[6];
!     char      **seq_values = NULL;
      char      **modifiers = NULL;
      char      **ptr;
      PQExpBufferData title;
***************
*** 869,874 ****
--- 870,904 ----
      tableinfo.tablespace = (pset.sversion >= 80000) ?
          atooid(PQgetvalue(res, 0, 6)) : 0;
      PQclear(res);
+
+     /*
+      * This is used to get the values of a sequence and store it in an
+      * array that will be used later.
+      */
+     if (tableinfo.relkind == 'S')
+     {
+         PGresult   *result;
+
+ #define SEQ_NUM_COLS 10
+         printfPQExpBuffer(&buf,
+                 "SELECT sequence_name, last_value, \n"
+                 "        start_value, increment_by, \n"
+                 "        max_value, min_value, cache_value, \n"
+                 "        log_cnt, is_cycled, is_called \n"
+                 "FROM \"%s\"",
+                 relationname);
+
+         result = PSQLexec(buf.data, false);
+         if (!result)
+             goto error_return;
+
+         seq_values = pg_malloc_zero((SEQ_NUM_COLS+1) * sizeof(*seq_values));
+
+         for (i = 0; i < SEQ_NUM_COLS; i++)
+             seq_values[i] = pg_strdup(PQgetvalue(result, 0, i));
+
+         PQclear(result);
+     }

      /* Get column info (index requires additional checks) */
      printfPQExpBuffer(&buf, "SELECT a.attname,");
***************
*** 932,938 ****
      }

      /* Set the number of columns, and their names */
!     cols = 2;
      headers[0] = gettext_noop("Column");
      headers[1] = gettext_noop("Type");

--- 962,968 ----
      }

      /* Set the number of columns, and their names */
!     cols += 2;
      headers[0] = gettext_noop("Column");
      headers[1] = gettext_noop("Type");

***************
*** 943,948 ****
--- 973,981 ----
          modifiers = pg_malloc_zero((numrows + 1) * sizeof(*modifiers));
      }

+     if (tableinfo.relkind == 'S')
+         headers[cols++] = gettext_noop("Value");
+
      if (verbose)
      {
          headers[cols++] = gettext_noop("Storage");
***************
*** 980,986 ****

          /* Type */
          printTableAddCell(&cont, PQgetvalue(res, i, 1), false);
!
          /* Extra: not null and default */
          if (show_modifiers)
          {
--- 1013,1023 ----

          /* Type */
          printTableAddCell(&cont, PQgetvalue(res, i, 1), false);
!
!         /* A special 'Value' column for sequences */
!         if (tableinfo.relkind == 'S')
!             printTableAddCell(&cont, seq_values[i], false);
!
          /* Extra: not null and default */
          if (show_modifiers)
          {
***************
*** 1543,1549 ****
      termPQExpBuffer(&buf);
      termPQExpBuffer(&title);
      termPQExpBuffer(&tmpbuf);
!
      if (show_modifiers)
      {
          for (ptr = modifiers; *ptr; ptr++)
--- 1580,1593 ----
      termPQExpBuffer(&buf);
      termPQExpBuffer(&title);
      termPQExpBuffer(&tmpbuf);
!
!     if (tableinfo.relkind == 'S')
!     {
!         for (ptr = seq_values; *ptr; ptr++)
!             free(*ptr);
!         free(seq_values);
!     }
!
      if (show_modifiers)
      {
          for (ptr = modifiers; *ptr; ptr++)