From: | "Ben" <reply(at)to-the-newsgroup(dot)com> |
---|---|
To: | pgsql-general(at)postgresql(dot)org |
Subject: | Are there commands to enquire about table structure? |
Date: | 2004-01-30 21:06:46 |
Message-ID: | b26aca210516c97d8f584b00d85acac6@news.teranews.com |
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Lists: | pgsql-general |
PostgreSQL mavens, can I ask the database, in a normal database query command, or in other words,
essentially using the same environment where I'd say...
SELECT count(*) FROM mytable [WHERE myconditions_obtain];
...to get # records in my table,
o How many fields mytable has as in:
SELECT fieldcount(*) from mytable
o What the names of the fields are as in:
SELECT fieldname(n) from mytable = one name ...OR...
SELECT fieldnames() from mytable = a row per field
o What type of field "fieldname" is as in:
SELECT fieldtype(fieldnumber) from mytable ...OR...
SELECT fieldtype(fieldname) from mytable ...OR...
SELECT fieldtypes() from mytable = a row per field
o How long a field is as in:
SELECT fieldlength(fieldnumber) from mytable ...OR...
SELECT fieldlength(fieldname) from mytable
SELECT fieldlengths() from mytable = a row per field
Ideally, I envision being able to say...
SELECT fieldnames(),fieldtypes(),fieldlengths() FROM customers;
...and I might get back:
[firstname],[char],[15]
[lastname],[char],[20]
[custnum],[int],NULL
etc...
...or maybe...
SELECT fieldnames(),fieldtypes() FROM customers;
...and I might get back:
[firstname],[char(15)]
[lastname],[char(20)]
[custnum],[int]
etc...
Maybe I could even say:
SELECT fieldnames(),fieldtypes() from customers WHERE fieldnames() ilike '%name%';
...and I might get back:
[firstname],[char(15)]
[lastname],[char(20)]
...where [custnum],[int] is left out because of the WHERE clause.
I would find this kind of capability very useful for certain types of flexible table
processing I'd like to do.
Thanks for any insight into this, I appreciate any and all input.
--Ben
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