Re: i have table - Mailing list pgsql-sql

From Markus Schaber
Subject Re: i have table
Date
Msg-id 45237D6E.1030601@logix-tt.com
Whole thread Raw
In response to i have table  ("Penchalaiah P." <penchalaiahp@infics.com>)
Responses Re: i have table
List pgsql-sql
Hi, Penchalaiah,

Penchalaiah P. wrote:

> now I want to add one more field in this table.. but that field has to
> come next to cda_no.. I mean as a 3^rd field.. If I am adding that field
> it is coming last field …

In SQL, field order in the table is not given by design.

A "SELECT * FROM table" might even give you the columns alphabetically
ordered, or in a different random order each time in a different server
implementation.

If you need the colums in a specific order, use "SELECT foo, bar, baz
FROM table" or create a View.

All relevant SQL constructs (SELECT, INSERT, UPDATE, COPY, etc.) let you
specify the columns explicitly to guarantee a given order.

> may I know how it is possible to that table…

If you _really_ want to do that despite what I wrote above, you have
several possibilities:

- COPY the table to some file, drop the table, recreate the table with the desired new column order, and then COPY the
tableback using an explicitly specified, correct row order. 

- use CREATE TABLE ... AS SELECT to select the data into a new table, drop the old table, rename the new one to the old
one.

In both cases, you've to recreate all missing indices, foreing key
constraints etc.


HTH,
Markus


--
Markus Schaber | Logical Tracking&Tracing International AG
Dipl. Inf.     | Software Development GIS

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