mussa...@csz.com wrote:
On Tue, August 4, 2015 11:19, Ryan Coleman wrote:
I have been a MySQL user and supporter for over a decade (since 2001)
and
I am almost ashamed to admit that I haven’t the faintest idea on how to
do
joins and unions.
I have a specific query I would love to run…
I have
, Ryan Coleman wrote:
I have been a MySQL user and supporter for over a decade (since 2001) and
I am almost ashamed to admit that I haven’t the faintest idea on how to do
joins and unions.
I have a specific query I would love to run…
I have two tables, one with Unique data (“images”) and one
I have been a MySQL user and supporter for over a decade (since 2001) and I am
almost ashamed to admit that I haven’t the faintest idea on how to do joins and
unions.
I have a specific query I would love to run…
I have two tables, one with Unique data (“images”) and one with corresponding
On Tue, August 4, 2015 11:19, Ryan Coleman wrote:
I have been a MySQL user and supporter for over a decade (since 2001) and
I am almost ashamed to admit that I haven’t the faintest idea on how to do
joins and unions.
I have a specific query I would love to run…
I have two tables, one
Parallel Universe* now features Parallel Network Query (Distributed Query)
which joins tables from multiple servers in the network with unprecedented
speed.
Parallel Network Query may also be used to speed up slow server by
distributing tables of the query to multiple servers for processing which
: Jeffrey Grollo [mailto:grol...@gmail.com]
Sent: Tuesday, July 10, 2012 2:50 PM
To: mysql@lists.mysql.com
Subject: Composite Index Usage in Joins
Hi,
I'm attempting to optimize a join and am having a difficult time using
multiple columns from a composite index. The second column of the
composite
Thanks for the guidance and references, Shawn.
On Wed, Jul 11, 2012 at 3:37 PM, Shawn Green shawn.l.gr...@oracle.com wrote:
Ranged scans only happen for the last portion of an index being used. OR
queries (or those using IN) can also only be applied to the last part of an
index search. This
On Wed, Jul 11, 2012 at 5:30 PM, Sergei Petrunia pser...@askmonty.org wrote:
I can provide a refutation. Ability to make a combined index access of
1. Equality with a non-constant: t.sec_id= p.sec_id
2. non-equality comparison with constants, trade_time IN ('2012-07-01',
'2012-07-02')
has
On 7/10/2012 5:50 PM, Jeffrey Grollo wrote:
Hi,
I’m attempting to optimize a join and am having a difficult time using
multiple columns from a composite index. The second column of the composite
key is being used when tested for equality, but not for IN or BETWEEN
criteria.
As an example, say
On Tue, Jul 10, 2012 at 05:50:07PM -0400, Jeffrey Grollo wrote:
Hi,
I’m attempting to optimize a join and am having a difficult time using
multiple columns from a composite index. The second column of the composite
key is being used when tested for equality, but not for IN or BETWEEN
Hi,
I’m attempting to optimize a join and am having a difficult time using
multiple columns from a composite index. The second column of the composite
key is being used when tested for equality, but not for IN or BETWEEN
criteria.
As an example, say that I’m searching two tables: portfolio and
, 2012 5:20 PM
To: mysql@lists.mysql.com
Subject: Re: forcing mysql to use batched key access (BKA) optimization for
joins
2012/04/10 15:58 -0400, Stephen Tu
select
c_custkey,
c_name,
sum(l_extendedprice * (100 - l_discount)) as revenue,
c_acctbal,
n_name,
c_address,
c_phone
Hi Stephen,
2012/04/10 15:58 -0400, Stephen Tu
| id | select_type | table| type | possible_keys | key
| key_len | ref | rows|
Extra |
2012/04/10 15:58 -0400, Stephen Tu
select
c_custkey,
c_name,
sum(l_extendedprice * (100 - l_discount)) as revenue,
c_acctbal,
n_name,
c_address,
c_phone,
c_comment
from CUSTOMER_INT, ORDERS_INT, LINEITEM_INT, NATION_INT
where
c_custkey = o_custkey
and l_orderkey =
Terry Van de Velde wrote:
Good Day,
I am attempting to do something new (to me) with MySQL. I am looking to have
my query return with the value in the visitor and home columns replaced with
the corresponding team name from the teams table. schedule.visitor and
schedule.home are essentially
-Original Message-
From: shawn.gr...@sun.com [mailto:shawn.gr...@sun.com]
Sent: December 12, 2009 4:39 PM
To: Terry Van de Velde
Cc: mysql@lists.mysql.com
Subject: Re: Multiple joins from same table?
Terry Van de Velde wrote:
Good Day,
I am attempting to do something new (to me) with MySQL. I
Good Day,
I am attempting to do something new (to me) with MySQL. I am looking to have
my query return with the value in the visitor and home columns replaced with
the corresponding team name from the teams table. schedule.visitor and
schedule.home are essentially foreign keys to
Terry Van de Velde wrote:
Good Day,
I am attempting to do something new (to me) with MySQL. I am looking to have
my query return with the value in the visitor and home columns replaced with
the corresponding team name from the teams table. schedule.visitor and
schedule.home are essentially
Hello:
I have a database with over 60 tables with thousands
to millions or rows in each.
I want to develop a summary of the data joined across
all the tables.
I can do this with a view, but I am concerned it will
take a lot of resources to perform all the joins required
by the view. Is a view
A view is no more or less efficient that the queries that make it up. Each
time you invoke the view, you repeat all the joins.
A join could be more efficient only if you go to a lot of effort to ensure
it forms the most efficient join(s) of the underlying tables.
Your solution of the summary
Jim:
A view is no more or less efficient that the queries that
make it up. Each
time you invoke the view, you repeat all the joins.
That is what I was afraid of. With the large number
of tables I have, the joins are going to take a lot
of cycles to run.
Your solution of the summary table
Dear Michail and Sergey,
Thank you very much for your responses and kind suggestions!
On 29.10.2009, at 16:53, Sergey Petrunya wrote:
this makes it clear that index on O1.tsn will not be useful. You
need indexes
on parent_tsn column.
mysql alter table taxonomic_units1 add index
| |
++-+---+--+---+--+-
+--++---+
6 rows in set (0.00 sec)
What is wrong with this query? Or is it a problem of all adjacency
list models?
Is there a way to get columns indexed using self-joins?
Thanks,
Olga
--
MySQL General Mailing List
Not sure if this is the exact problem you're trying to solve, but this helped
me in a similar situation.
http://dev.mysql.com/tech-resources/articles/hierarchical-data.html
kabel
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MySQL General Mailing List
For list archives: http://lists.mysql.com/mysql
To unsubscribe:
Thanks Kabel,
Not sure if this is the exact problem you're trying to solve, but
this helped
me in a similar situation.
http://dev.mysql.com/tech-resources/articles/hierarchical-data.html
Yes, I have seen this article before, and it is really nice. However
they do not discuss any
adjacency list
models?
Is there a way to get columns indexed using self-joins?
For an outer join like
... taxonomic_units1 AS O1
LEFT OUTER JOIN taxonomic_units1 AS O2
ON O1.tsn = O2.parent_tsn
current optimizer has only one option(*): use Nested-Loops Join algorthm, with
the outer table being
On Thu, Oct 29, 2009 at 07:53:25PM +0300, Sergey Petrunya wrote:
... taxonomic_units1 AS O1
LEFT OUTER JOIN taxonomic_units1 AS O2
ON O1.tsn = O2.parent_tsn
current optimizer has only one option(*): use Nested-Loops Join algorthm, with
the outer table being the first one. That is, it
| |
++-+---+--+---+--+-+--++---+
6 rows in set (0.00 sec)
What is wrong with this query? Or is it a problem of all adjacency
list models?
Is there a way to get columns indexed using self-joins?
Thanks,
Olga
--
MySQL General Mailing List
For list
*From:* Victor Subervi [mailto:victorsube...@gmail.com]
*Sent:* Thursday, October 01, 2009 3:04 PM
*To:* Gavin Towey; mysql@lists.mysql.com
*Subject:* Re: Nested Joins
Well, your syntax is *exactly* what I had (with a few cosmetic changes).
I've been over the MySQL manual on joins
Hi;
I'm new to join statements. Here's my python syntax:
cursor.execute('select * from %s left join products on
%s.Item=products.Item (left join categories on
products.Category=categories.ID);' % (client, client))
I believe it's clear how I want to nest, but I don't know how to repair my
Joins aren't nested like that, unless you use a subquery. I think you just
need to remove the parens around the second join.
For better help:
1. show the real SQL -- echo the statement. Most people here don't like
looking at app code because your variables could contain anything.
2. Give
On Thu, Oct 1, 2009 at 4:03 PM, Gavin Towey gto...@ffn.com wrote:
Joins aren't nested like that, unless you use a subquery. I think you just
need to remove the parens around the second join.
I tried that and no go :(
For better help:
1. show the real SQL -- echo the statement. Most
on p.Category=cat.ID
Make your code produce the above, and you should be fine. I suspect you don't
need LEFT JOIN there, an inner join will suffice.
For more info on joins:
http://hashmysql.org/index.php?title=Introduction_to_Joins
For more indepth info:
http://dev.mysql.com/tech-resources/articles
Well, your syntax is *exactly* what I had (with a few cosmetic changes).
I've been over the MySQL manual on joins with no luck. I'll read over your
resources tonight. Any other ideas would be appreciated.
Thanks,
V
On Thu, Oct 1, 2009 at 4:49 PM, Gavin Towey gto...@ffn.com wrote:
Victor
the query you're building to a string, then printing it out so you
know *exactly* what you're sending to mysql.
Regards,
Gavin Towey
From: Victor Subervi [mailto:victorsube...@gmail.com]
Sent: Thursday, October 01, 2009 3:04 PM
To: Gavin Towey; mysql@lists.mysql.com
Subject: Re: Nested Joins
Well, your
going well so far, and several ColdFusion pages written already.
Need to do one for a Purchase Order Report for ...
- given SupplierCode
- given StartDate and EndDate of Orders
My problem is in the CFquery - understanding what JOINS to use and in what
order to use them.
Which kind
ColdFusion pages written already.
Need to do one for a Purchase Order Report for ...
- given SupplierCode
- given StartDate and EndDate of Orders
My problem is in the CFquery - understanding what JOINS to use and in what
order to use them.
(it is a MyISAM database
- understanding what JOINS to use and in what
order to use them.
(it is a MyISAM database = no constraints)
--
I am using the free version of SPAMfighter.
We are a community of 6 million users fighting spam.
SPAMfighter has removed 12908 of my spam emails to date.
Get the free SPAMfighter here: http
I have 3 tables that are 1:1 and will always have a row for a given
product,_code date. If I want to join them together, is it going to be
faster to use an equi join or a left join, or does it matter?
Who cares, they are -different- things symantically, use the correct type of
join for
IIRC it does not matter. But you can double-check my opinion with EXPLAIN.
A.
On Thu, Mar 12, 2009 at 11:41 AM, mos mo...@fastmail.fm wrote:
I have 3 tables that are 1:1 and will always have a row for a given
product,_code date. If I want to join them together, is it going to be
faster to
On Thu, Mar 12, 2009 at 8:41 AM, mos mo...@fastmail.fm wrote:
I have 3 tables that are 1:1 and will always have a row for a given
product,_code date. If I want to join them together, is it going to be
faster to use an equi join or a left join, or does it matter?
IIRC:With an inner join the
I have 3 tables that are 1:1 and will always have a row for a given
product,_code date. If I want to join them together, is it going to be
faster to use an equi join or a left join, or does it matter?
TIA
Mike
--
MySQL General Mailing List
For list archives: http://lists.mysql.com/mysql
To
of JOINs,
to give the following output ...
1) Who is assigned what assets?
2) What maintenance has been carried out on each asset?
3) Which assets have not undergone any maintenance?
4) Who hasn't been assigned any assets?
5) Which assets have not been scheduled for maintenance?
6
Hi Phil,
you seem quite a bit confused!
I would not step to use joins before understanding the 'simple' logic
behind,
otherwise you will be always confused by the syntax.
There are many, many, many resources (thanks to Tim!)
I will try to give you a simple overview of joins but please get more
Claudio Nanni wrote:
Hi Phil,
you seem quite a bit confused!
I would not step to use joins before understanding the 'simple' logic
behind,
otherwise you will be always confused by the syntax.
There are many, many, many resources (thanks to Tim!)
I will try to give you a simple overview
quite a bit confused!
I would not step to use joins before understanding the 'simple' logic
behind,
otherwise you will be always confused by the syntax.
There are many, many, many resources (thanks to Tim!)
I will try to give you a simple overview of joins but please get more
confortable
a proper
column name though. In your example, the concat_ws expresion has an
alias so in the queries result this name will be used instead of the
expression used to select.
A propos: The problem with your first query was that you were using
natural joins. Natural joins match up all columns
of the
expression used to select.
A propos: The problem with your first query was that you were using
natural joins. Natural joins match up all columns that have the same
name in both tables automatically. I consider it bad practice to use
it as it might have unexpected results, especially when you alter
I have been searching and searching for a clear and logical explanation
of JOINs and have found nothing that can be reasonably understood.
Perhaps I am dense or from another planet, but nothing seems to fall
into place.
I need to display all the books (with their respective authors and
publishers
= 'Plates' AND Plates.Id
= Inventory.ItemId
LEFT OUTER JOIN Cups ON Inventory.ItemType = 'Cups' AND Cups.Id =
Inventory.ItemId
LEFT OUTER JOIN Flatware ON Inventory.ItemType = 'Flatware' AND
Flatware.Id = Inventory.ItemId
WHERE Inventory.id IN (2, 4, 5)
In the query above, the joins on both
I have two indexed MyISAM tables, each in a separate database. If I do a
left join on the two tables, it takes 2 minutes to return the 5,000 rows.
The same join on similar tables in the same database would take 5-10
seconds. Both databases are on the same drive. So why is it 10x slower when
Both times seem a bit long, even if you database has millions of rows.
Can you post and explain of your query? That they are in different
databases should have minimal effect on your query.
Brent
On Oct 3, 2008, at 12:14 PM, mos wrote:
I have two indexed MyISAM tables, each in a separate
the
count of records from sales.
Can someone assist me with this? I have tried differance variants of joins
and none of the results are correct.
Sales tbl doesnt have the companyID, nor does IGuser
Steven,
Since this isn't a PHP-specific question, you'll probably receive
better
Cool it's good to know thank you.
On 25/01/2008, Jay Pipes [EMAIL PROTECTED] wrote:
Nope, no difference, AFAIK.
Alex K wrote:
Any ideas pertaining this newbie question?
Thank you so much,
Hi Guys,
Is there a performance hit when joining across multiple databases as
opposed to
Any ideas pertaining this newbie question?
Thank you so much,
Hi Guys,
Is there a performance hit when joining across multiple databases as
opposed to joining multiples tables in one database? Suppose the same
tables are available across all databases.
Thank you,
Alex
--
MySQL
Nope, no difference, AFAIK.
Alex K wrote:
Any ideas pertaining this newbie question?
Thank you so much,
Hi Guys,
Is there a performance hit when joining across multiple databases as
opposed to joining multiples tables in one database? Suppose the same
tables are available across all
Hi,
I need some urgent for sql query.. It will be great if someone could help
me..
I have ARTICLE, FAVORITE_ARTICLES, RATING Tables apart from other table
USER, CHANNEL, CATEGORY etc
ARTICLE table stores a user's article, FAVORITE_ARTICLES will store a user's
favorite articles, and rating
Hi Guys,
Is there a performance hit when joining across multiple databases as
opposed to joining multiples tables in one database? Suppose the same
tables are available across all databases.
Thank you,
Alex
--
MySQL General Mailing List
For list archives: http://lists.mysql.com/mysql
To
Hi all,
I have a query that is not quite producing what I expected:
select
n.nid,
n.title,
DATE_FORMAT(FROM_UNIXTIME(n.created), '%c/%e/%Y') as created,
c.field_product_price_value as price,
d.name,
t.tid,
v.value AS vote_average
from
node n
left join
Hi,
I found one thread on this that included some people's opinions, but I
haven't been able to find anyone who has actually done some performance
testing to see if there is a cost and what that cost is to doing cross
database joins. I do tend to want to keep everything in one DB
Hi,
I have the following sql request:
SELECT projects.`id` AS t0_r0, projects.`name` AS
t0_r1, projects.`abbreviated_name` AS t0_r2,
projects.`producer` AS t0_r3, projects.`tel_1` AS
t0_r4, projects.`tel_2` AS t0_r5, projects.`recital`
AS t0_r6, projects.`completed_flag` AS t0_r7,
tom wang wrote:
Hi,
I have the following sql request:
[snipped, for the sake of the children]
As you can see I have two left outerjoins involving
the readerships table:
LEFT OUTER JOIN readerships ON readerships.topic_id =
topics.id
and
LEFT OUTER JOIN readerships readerships_topics ON
tom wang schrieb:
Hi,
I have the following sql request:
SELECT projects.`id` AS t0_r0, projects.`name` AS
[..endless sql..]
Hi Tom,
did you understand that query (in lets say 3 months) if you need to fix
a bug? If not it maybe better to simplify that.
regards
-ralf
--
MySQL General
Hi,
First, sorry, I kind of messed of with copy and
pasting (it's been a long day) and forgot to strip all
the useless part (for the sake of explaining my
problem) between select and from...
SELECT * FROM projects LEFT OUTER JOIN forums ON
forums.work_id = projects.id AND forums.work_type =
tom wang wrote:
Hi,
First, sorry, I kind of messed of with copy and
pasting (it's been a long day) and forgot to strip all
the useless part (for the sake of explaining my
problem) between select and from...
SELECT * FROM projects LEFT OUTER JOIN forums ON
forums.work_id = projects.id AND
--- [EMAIL PROTECTED] a écrit :
tom wang wrote:
Hi,
First, sorry, I kind of messed of with copy and
pasting (it's been a long day) and forgot to strip
all
the useless part (for the sake of explaining my
problem) between select and from...
SELECT * FROM projects LEFT
more than one that syntax wont work because
the second join will be trying to join to the first lookup table no the
main table. Is there a way around this or do I need to just do joins
using this syntax
SELECT x, y, z
FROM table t, lookupA la, lookupB lb
WHERE t.aID = a.aID AND t.bID = b.bID
need to join more than one that syntax wont work because
the second join will be trying to join to the first lookup table no the
main table. Is there a way around this or do I need to just do joins
using this syntax
SELECT x, y, z
FROM table t, lookupA la, lookupB lb
WHERE t.aID = a.aID
join will be trying to join to the first lookup table no the
main table. Is there a way around this or do I need to just do joins
using this syntax
SELECT x, y, z
FROM table t, lookupA la, lookupB lb
WHERE t.aID = a.aID AND t.bID = b.bID
--
Chris W
KE5GIX
Protect your digital freedom
Hi all,
First sorry my bad english :)
I having a problem with a large join with 10 tables with 70Gb of text data,
some joins executed by index but some others not.
I´m work with HP SERVER (Proliant NL-150) a 2 Xeon 2 Duo with 3Gb Ram and
RAID 0.
When executed to a client with small datasets
and include
the output of SHOW CREATE TABLE for the tables, your query, and the
result of EXPLAIN for the query.
[ Triadbrasil ] Filipe Tomita wrote:
Hi all,
First sorry my bad english :)
I having a problem with a large join with 10 tables with 70Gb of text data,
some joins executed by index but some
I hope someone can clue me in what a syntax of query that produces the
same would look like for MySQL 5.0.12
Old query meant to list most recent message from each thread, e.g.
select * from messages left join messages as messages_ on
messages.thread = messages_.thread and messages.created
It worked in 4.x but does not work in the new syntax. How should I
rewrite it to get the same result?
OK, that was a lie. It works in 5.x as well. I should learn to
describe my problem more accurately as well as RTFM :-(
The correct description of the query in question would have been:
select
appreciate your help.
Thanks
Murthy
Michael Dykman wrote:
a left join and a right join are 2 very distinct things... It is not
clear from your text what it is you exactly are going for here but I
doubt that applying either LEFT or RIGHT to ALL of your (many) joins
is going to give it to you
12:15 AM
To: mysql@lists.mysql.com
Subject: Joins versus Grouping/Indexing: Normalization Excessive?
So I'm currently designing a database for a web site and
intra net for my
campuses student radio. Since I'm not getting paid for this
and I'm doing
this in my free time I kinda want to take my
I tried the following 2 SQL's and the results are less than satisfactory. The
RIGHT join does not show where disposition is NULL. The LEFT join shows
dispositions as NULL where they shouldn't be. Also the LEFT join generates more
dupes. Any way to fix this?
select cust.first as FIRST,
a left join and a right join are 2 very distinct things... It is not
clear from your text what it is you exactly are going for here but I
doubt that applying either LEFT or RIGHT to ALL of your (many) joins
is going to give it to you. You need to stop and examine the
relationships between
... It is not
clear from your text what it is you exactly are going for here but I
doubt that applying either LEFT or RIGHT to ALL of your (many) joins
is going to give it to you. You need to stop and examine the
relationships between the tables in this query and determine which
class of JOIN you
[EMAIL PROTECTED] wrote:
a left join and a right join are 2 very distinct things... It is not
clear from your text what it is you exactly are going for here but I
doubt that applying either LEFT or RIGHT to ALL of your (many) joins
is going to give it to you. You need to stop and examine
So I'm currently designing a database for a web site and intra net for my
campuses student radio. Since I'm not getting paid for this and I'm doing
this in my free time I kinda want to take my time and have the system setup
as perfectly as any one college student can.
I'm currently debating on
I think you're approaching this from the wrong angle. You'll want to put
the data at the highest level at which it changes.
i.e. If every song on an album is always the same year, put it at the
album level, however, if it changes from song to song on a particular
album, then you want it at
Hi -
I'm having an issue with left joins and multiple tables. I have a table
which is a fairly simple name-value pair table:
create table
{
acnt char(20),
item char(40),
value char (60)
}
I want to pull out all of a subset of the values for a particular account.
It works for
two
I'm missing something really silly in a query.
I want to produce a list of accounts, the invoices and receipts and the
balance against them.
Simply, there is an accounts table, invoices and receipts.
I want to show the account details, sum(invoices), sum(receipts) and the
balance. There is a
You're left joining invoices, then left joining receipts. A left join will replicate rows on the left side to match the number of
rows it found in the join, or just leave 1 row with NULL values (as you probably know). This is where your problem is. You were
correct to try to use left joins
I thought I'd pass this on for those of you that have slow table joins. I'm
sure a few of you have already figured this out, but if not, here it is.
I have some slow table joins, namely a 6 table join using a primary integer
index field which takes 15 seconds to pull in 18k rows from each
Are there any hard and fast rules for this? If someone has already
compiled a list I'd love to see it.
For example:
* When a subselect will eliminate duplicates a join might introduce.
Change:
SELECT DISTINCT Acl.*
FROM Acl
JOIN Link ON Link.childID = Acl.ID
JOIN Paths ON
Subject: Complex SQL for multiple joins
Hi,
For my current website project I'm developing a fine-grained access control
system.
I have the schema mostly worked out, although it will be having additional
data added to parts of it later.
For the record, I have 6 tables:
users (contains all my
for multiple joins
Hi,
For my current website project I'm developing a fine-grained access control
system.
I have the schema mostly worked out, although it will be having additional
data added to parts of it later.
For the record, I have 6 tables:
users (contains all my individual users
; mysql@lists.mysql.com
Subject: Re: Complex SQL for multiple joins
Also, depending on the number of permissions you are tracking, you could
use a single INT field and do bitwise ORing in your application to
determine permission checks...
Though I usually don't recommend denormalizing the schema
Hi,
For my current website project I'm developing a fine-grained access control
system.
I have the schema mostly worked out, although it will be having additional
data added to parts of it later.
For the record, I have 6 tables:
users (contains all my individual users)
usergroups (contains all
On 8/20/06, Ow Mun Heng [EMAIL PROTECTED] wrote:
I'm have a query like so
select
A,
index_A
from
tableA
join tableB
on tableB.indexA = tableA.indexA
select
A,
index_A
from
tableA
join tableB
on tableB.A = tableA.A
whcih would be more efficient? using the where clause which uses the
index or
On Sun, 2006-08-20 at 19:59 +1000, chris smith wrote:
On 8/20/06, Ow Mun Heng [EMAIL PROTECTED] wrote:
I'm have a query like so
select
A,
index_A
from
tableA
join tableB
on tableB.indexA = tableA.indexA
select
A,
index_A
from
tableA
join tableB
on tableB.A =
Ow Mun Heng wrote:
On Sun, 2006-08-20 at 19:59 +1000, chris smith wrote:
On 8/20/06, Ow Mun Heng [EMAIL PROTECTED] wrote:
I'm have a query like so
select
A,
index_A
from
tableA
join tableB
on tableB.indexA = tableA.indexA
select
A,
index_A
from
tableA
join tableB
on tableB.A = tableA.A
On Mon, 2006-08-21 at 07:39 +1000, Chris wrote:
Ow Mun Heng wrote:
On Sun, 2006-08-20 at 19:59 +1000, chris smith wrote:
On 8/20/06, Ow Mun Heng [EMAIL PROTECTED] wrote:
I'm have a query like so
select
A,
index_A
from
tableA
join tableB
on tableB.indexA = tableA.indexA
I'm have a query like so
select
A,
index_A
from
tableA
join tableB
on tableB.indexA = tableA.indexA
select
A,
index_A
from
tableA
join tableB
on tableB.A = tableA.A
whcih would be more efficient? using the where clause which uses the
index or the one which isn't index?
--
MySQL General
Brian E Boothe wrote:
hi all
Can someone provide a small project using inner and outter joins with
querys thanks alot
create table t1 (id int);
create table t2 (id int);
This will find everything that has an entry in both tables:
select * from t1 inner join t2;
This will find records
hi all
Can someone provide a small project using inner and outter joins with
querys thanks alot
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joins like this?
Thanks
Steffan
---
T E L 6 0 2 . 5 7 9 . 4 2 3 0 | F A X 6 0 2 . 9 7 1 . 1 6 9 4
Steffan A. Cline
[EMAIL PROTECTED] Phoenix, Az
http://www.ExecuChoice.net
;
Is it legal to do multiple joins like this?
Thanks
Steffan
forum_messages does not take part in any selection or any where clause.
You have 5 tables listed, with only 4 of them appearing in 2 disjointed,
and improperly formed joins.
From the comma separated table list after a LEFT JOIN, I
A. Cline [EMAIL PROTECTED]
Cc: mysql@lists.mysql.com
Subject: Re: Multiple joins
Steffan A. Cline wrote:
What am I missing here?
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