On Sat, Mar 8, 2008 at 11:55 PM, Waynn Lue <[EMAIL PROTECTED]> wrote:
Subject: Re: mysqldump on specific columns only?
I'm trying to dump all the columns of a table but one in a
restructuring of my schema.
By "dump", I assume you mean "output", not "delete".
I suspect I'm too inexperienced in MySQL or I don't understand the
question, because I don't see why you haven't mentioned
ALTER TABLE DROP COLUMN. Or, if you don't want to touch the original
database but rather a copy database: mysqldump, load it into another
database, ALTER TABLE DROP COLUMN. It's true that you wrote
since the files are going to be rather big.
The second notion has the disadvantage that the data will be copied
three times (mysqldump, load, ALTER TABLE). On the other hand, you
have the full reliability of mysqldump, with its care in copying
CREATE TABLEs and data correctly.
Am I perhaps misunderstanding?
On Sun, 9 Mar 2008, Rob Wultsch <[EMAIL PROTECTED]> wrote:
I would probably use [SELECT] INTO OUTFILE. Any particular reason it
does not work?
It's not well-suited for "restructuring of my schema". mysqldump
emits SQL that can be used immediately to create the table with
exactly the same data types and column names and keys and other
properties (like NOT NULL), and to insert data into columns with
quoting and escaping as needed, and nice little flourishes like DROP
TABLE IF EXISTS, LOCK TABLES, UNLOCK TABLES.
mysql> select c1,c2 from t INTO OUTFILE 'outfile';
Query OK, 4 rows affected (0.00 sec)
outfile contents:
1 2
4 5
7 8
10 11
That provides only the data to insert. Further, it would require
considerable massaging to get it into the form of INSERT statements,
though for all I know MySQL provides other mechanisms to load that
sort of data. But those are tab-separated columns: what if one of the
columns were a text field with a literal tab?
--
Tim McDaniel, [EMAIL PROTECTED]
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