i saw this
In MySQL, joins work for INSERT,
UPDATE, and DELETE statements. It's
possible to change data in more than
one table when joining tables in an
UPDATE or DELETE statement.
in an answer for a question from the mysql certification guide. is it true? inserts with joins? an example of it?
...
I have 2 tables, say table A and table B and I want to perform a join, but the matching condition has to be where a column from A 'is like' a column from B meaning that anything can come before or after the column in B:
for example: if the column in A is 'foo'. Then the join would match if column in B is either: 'fooblah', 'somethingfo...
Say I have two tables called A (fields: id, phase, name) and B(fields: id, AID, APHASE, void).
I need to show all records from A except for records where A.id = B.AID and A.phase = B.APHASE and void = 0.
Environment is MySQL.
...
I have three tables setup: POSTS, DISCUSSIONS, and COMMENTS. The layout is as follows:
POSTS
id | user_id | title | body | created
DISCUSSIONS
id | post_id | user_id | title | body | created
COMMENTS
id | post_id | discussion_id | user_id | title | body | created
A post hasMany DISCUSSIONS, which then hasMany COMMENTS.
What I need ...
I have a basic query that goes from 6 seconds to 1 second just by changing one join from LEFT JOIN to LEFT HASH JOIN or 'LEFT LOOP JOIN'. Can anyone explain why this would cause such a large increase in performance and why SQL's optimizer isn't figuring it out on it's own?
Here is roughly what the SQL looks like:
SELECT
a.[ID]
FROM...
I have a query similar to the following:
SELECT
users.id FROM users LEFT JOIN sales ON installations.customer = users.id
What I would like to say is something like "WHERE count(sales.id) > 4" - meaning that if the user has more than 4 sales assoc with them. I am not sure if I am going about this the wrong way or not though
...
I have a relatively simple query joining two tables. The "Where" criteria can be expressed either in the join criteria or as a where clause. I'm wondering which is more efficient.
Query is to find max sales for a salesman from the beginning of time until they were promoted.
Case 1
select salesman.salesmanid, max(sales.quantity)
from...
I have two tables:
Companies: (id, name, city)
Workers: (id, name)
I would like to get all companies and sort them by numbers of employes.
The result should give:
count | company id | company name | city
------------------------------------------
90 6 foo corp NY
45 9 bar corp LA
0 ...
I have this releases table in a SQLite3 database, listing each released version of an application:
|release_id|release_date|app_id|
|==========|============|======|
| 1001| 2009-01-01 | 1|
| 1003| 2009-01-01 | 1|
| 1004| 2009-02-02 | 2|
| 1005| 2009-01-15 | 1|
So for each app_id, there will be multi...
I have two tables:
Companies: (id, name)
Workers: (id, name, country)
I would like to get all companies and sort them by numbers of employees from a given country.
For a query looking for companies that have more workers from the USA, the result should give:
#workers from USA | company id | company name
----------------------------...
Hi,
i have a master table page, and a relative table page_lang.In page_lang i hold the page data for each language.
Using the the above code
SELECT * FROM pages as p
RIGHT JOIN pages_lang as l ON
l.pageID=p.pageID
i get the rows containing common data form pages and language data from page_lang.All OK
The problem is when rty to lim...
I am having some problems with MySQL and selecting column count from a joined table. I have a feeling this is going to require a sub-select statement to fetch the rows I would like to join instead of doing it in my primary where condiutional.
I am trying to select a list of project which are linked to a certain user. I would also like t...
Thanks for your help!
I'd like to output all companyName entries that have uploads across any of their serverFiles as:
companies.companyName - count(files.fileID) - sum(serverFiles.uniqueUploads)
Initech Ltd. - 11 - 24931
Epiphyte Inc. - 23 - 938821
Here are the relavent parts of my table structure:
Table: companies
c...
I need to make an outer join query that retrieves all of the definitions and any properties they have associated with them that are associated with a certain company.
I have two Hibernate models objects:
class PropertyDefinition {
@Id
private Long id;
@Column
private String name;
@OneToMany(mappedBy = "propert...
I have a DataTable and a List of objects. I need to return all rows in the DataTable where a property in the List is a certain value. The List is only used for filtering the datatable (but the filter column isn't containined in the datatable.
I'm sure this must be possible with link
The DataTable contains:
MembershipID Username Pas...
I have 3 different transaction tables, which look very similar, but have slight differences. This comes from the fact that there are 3 different transaction types; depending on the transaction types the columns change, so to get them in 3NF I need to have them in separate tables (right?).
As an example:
t1:
date,user,amount
t2:
date,us...
How can I get all products from customers1 and customers2 include their customer names?
customer1 table
cid name1
1 john
2 joe
customer2 table
cid name2
p1 sandy
p2 linda
product table
pid cid pname
1 1 phone
2 2 pencil
3 p1 pen
4 p2 paper
Result should be like this
pid cid pname name1 name2
1 1 phone ...
I have a workorder system using SQL Express 2008. I have a table called Workorders that has several personnel that are linked to it via UserID. In the Workorder table I have TechID for the Technician, CustomerID for the Customer, QAID for quality assurance. These are linked back to the User Table via UserID (User Table PK). I want to joi...
Hi
I have a union opertaion between two tables
SELECT
ID_1,
name_1,
surname_1,
FROM
T_ONE
UNION
SELECT
ID_2,
name_2,
surname_2
FROM
TABLE_2
now I want to join the result of this JOIN operation with another one table or even with all TABLE_1.
How can I handle this new table result of the UNION.
for ex after the previous UN...
Hi Everyone,
I wanna learn how to join two tables which are located two different SQL Server instances.
Thanks in advance.
...