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I have a database called programs created as
CREATE TABLE programs (
name varchar(200) NOT NULL,
role varchar(200) NOT NULL,
section text[] NOT NULL,
sub_section text[] NOT NULL,
title text[] NOT NULL
);
INSERT INTO programs (name, role, section, sub_section, title) VALUES
('John','Lead','{"VII","VII","VII"}','{"A","A","C"}','{"STUDY","STUDY","STUDY"}'),
('Olga','Member','{"VII","VII"}','{"A","A"}','{"STUDY","STUDY"}'),
('Ben','Co-Lead','{"XI","X"}','{"A","B"}','{"STUDY","TRAVEL"}'),
('Ana','Member','{"VII","II","VI"}','{"A","ALL","B"}','{"STUDY","STUDY","TRAVEL"}');
Here's what the table looks like
| name | role | section | sub_section | title |
| ---- | ------- | ------------ | ----------- | ------------------------ |
| John | Lead | VII,VII,VII | A,A,C | STUDY,STUDY,STUDY |
| Olga | Member | VII,VII | A,A | STUDY,STUDY |
| Ben | Co-Lead | XI,X | A,B | STUDY,TRAVEL |
| Ana | Member | VII,II,VI | A,ALL,B | STUDY,STUDY,TRAVEL |
I want to identify distinct combinations across the section, sub-section, and title columns, as well as unnesting to get this as output
| name | role | section.sub_section | title |
| ---- | ------- | ------------------- | ------------------------ |
| John | Lead | VII.A | STUDY
| John | Lead | VII.C | STUDY
| Olga | Member | VII.A | STUDY
| Ben | Co-Lead | XI.A | STUDY
| Ben | Co-Lead | X.B | TRAVEL
| Ana | Member | VII.A | STUDY
| Ana | Member | II.ALL | STUDY
| Ana | Member | VI.B | TRAVEL
I'm fairly new to SQL and I'm really struggling with getting desired output. Your help would be very much appreciated.
You desired data does not show "combinations across the section, sub-section, and title columns", it seems that you require to match corresponding array based on positions, so you can just unnest and group by fields which you want to distinct on.
Assuming that corresponding columns contain arrays of varchars (if not - you will need to use some string functions to convert them):
-- sample data
WITH dataset (name, role, section, sub_section, title) AS (
VALUES ('John','Lead',array['VII','VII','VII'],array['A','A','C'],array['STUDY','STUDY','STUDY']),
('Olga','Member',array['VII','VII'],array['A','A'],array['STUDY','STUDY']),
('Ben','Co-Lead',array['XI','X'],array['A','B'],array['STUDY','TRAVEL']),
('Ana','Member',array['VII','II','VI'],array['A','ALL','B'],array['STUDY','STUDY','TRAVEL'])
)
--query
select name,
role,
sec || '.' || sub_sec "section.sub_section",
t title
from dataset
cross join unnest(section, sub_section, title) as t(sec, sub_sec, t)
group by name, role, sec, sub_sec, t
order by name
Output:
name
role
section.sub_section
title
Ana
Member
VII.A
STUDY
Ana
Member
II.ALL
STUDY
Ana
Member
VI.B
TRAVEL
Ben
Co-Lead
XI.A
STUDY
Ben
Co-Lead
X.B
TRAVEL
John
Lead
VII.A
STUDY
John
Lead
VII.C
STUDY
Olga
Member
VII.A
STUDY
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I have spent hours researching how to write the proper SQL for the following task, and finally I feel that I have to get some help as this is the most complex SQL query I have ever had to write :(
I am putting together an email list with all the email adresses that we have on our customers.
I have two tables: one customer table that contains customer level information, and one contact person table that contains person level information. Most of the data is overlapping, so the same email adress will occure in both tables. But the email adress field can be empty in both tables, and I do not want to return any empty rows.
Users that buy in our physical store are often only registered in the customer level table, but users that buys online are always registered both in the customer level table and the person level table.
I want to create a full list where I get all email adresses, where all email adresses are unique, no email adresses are duplicates and no email adresses are null.
Also I want to join in columns from the customer table when the data is retrieved from the person table (the zip code in my example below).
Customers
| CustomerID | Firstname | Lastname | Email | Zipcode |
| 22 | Jeff | Carson | jeffcar#mail.com | 81712 |
| 29 | John | Doe | null | 51211 |
| 37 | Gina | Andersen | null | 21147 |
| 42 | Brad | Cole | brad#company.org | 39261 |
Contact persons
| PersonID | CustomerID | Firstname | Lastname | Email |
| 8712 | 22 | Jeff | Carson | null || 8916 | 29 | Jane | Doe | jane#doe.net || 8922 | 29 | Danny | Doe | null |
| 9181 | 37 | Gina | Andersen | gina#gmail.com |
| 9515 | 37 | Ben | Andersen | ben88#gmail.com |
I want to join the tables to generate the following:
Final table
| PersonID | CustomerID | Firstname | Lastname | Email | Zipcode |
| 8712 | 22 | Jeff | Carson | jeffcar#mail.com | 81712 |
| 8916 | 29 | Jane | Doe | jane#doe.net | 51211 |
| 9181 | 37 | Gina | Andersen | gina#gmail.com | 21147 |
| 9515 | 37 | Ben | Andersen | ben88#gmail.com | 21147 |
| null | 42 | Brad | Cole | brad#company.org | 39261 |
I guessed this would be a fairly common task to do, but I haven't found anyone with a similar question, so I put my trust in the expertise out there.
This SQL will get you exactly the results table you were looking for. I've made a live demo you can play with here at SQLFiddle.
SELECT
ContactPerson.PersonID,
Customer.CustomerID,
COALESCE(ContactPerson.FirstName, Customer.FirstName) AS FirstName,
COALESCE(ContactPerson.LastName, Customer.LastName) AS LastName,
COALESCE(ContactPerson.Email, Customer.Email) AS Email,
Customer.ZipCode
FROM Customer
LEFT JOIN ContactPerson
ON ContactPerson.CustomerID = Customer.CustomerID
WHERE COALESCE(ContactPerson.Email, Customer.Email) IS NOT NULL
Results (identical to your desired results):
| PersonID | CustomerID | FirstName | LastName | Email | ZipCode |
| 8712 | 22 | Jeff | Carson | jeffcar#mail.com | 81712 |
| 8916 | 29 | Jane | Doe | jane#doe.net | 51211 |
| 9181 | 37 | Gina | Andersen | gina#gmail.com | 21147 |
| 9515 | 37 | Ben | Andersen | ben88#gmail.com | 21147 |
| NULL | 42 | Brad | Cole | brad#company.org | 39261 |
A quick explanation of some key points to aid understanding:
The query uses a LEFT JOIN to join the two tables together. JOINs are pretty common once you get into SQL problems like this. I won't go into an in-depth explanation here: now that you know what they are called you should have no trouble Googling for loads of info on them!
NB: COALESCE basically means 'the first one of these options which isn't null' (docs). So this query will grab their name and email address from ContactPerson IF POSSIBLE, otherwise from Customer. If NEITHER of these tables hold an email address, then the WHERE clause makes sure that record isn't included at all, as required.
This will work:
SELECT b.PersonID
,a.CustomerID
,a.FirstName
,a.LastName
,COALESCE(a.Email,b.Email) AS Email
,a.ZipCode
FROM Customers a
LEFT JOIN Contact b
ON a.CustomerID = b.CustomerID
WHERE COALESCE(a.Email, b.Email) IS NOT NULL
Demo: SQL Fiddle
select con.personid,
con.customerid,
con.firstname,
con.lastname,
coalesce(con.email, cus.email) email,
cus.zipcode
from contact_persons con
right join
customers cus
on con.customerid = cus.customerid
I appologize if the title does not make sense. I am trying to do something that is probably simple, but I have not been able to figure it out, and I'm not sure how to search for the answer. I have the following MDX query:
SELECT
event_count ON 0,
TOPCOUNT(name.children, 10, event_count) ON 1
FROM
events
which returns something like this:
| | event_count |
+---------------+-------------+
| P Davis | 123 |
| J Davis | 123 |
| A Brown | 120 |
| K Thompson | 119 |
| R White | 119 |
| M Wilson | 118 |
| D Harris | 118 |
| R Thompson | 116 |
| Z Williams | 115 |
| X Smith | 114 |
I need to include an additional column (gender). Gender is not a metric. It's just another dimension on the data. For instance, consider this query:
SELECT
gender.children ON 0,
TOPCOUNT(name.children, 10, event_count) ON 1
FROM
events
But this is not what I want! :(
| | female | male | unknown |
+--------------+--------+------+---------+
| P Davis | | | 123 |
| J Davis | | 123 | |
| A Brown | | 120 | |
| K Thompson | | 119 | |
| R White | 119 | | |
| M Wilson | | | 118 |
| D Harris | | | 118 |
| R Thompson | | | 116 |
| Z Williams | | | 115 |
| X Smith | | | 114 |
Nice try, but I just want three columns: name, event_count, and gender. How hard can it be?
Obviously this reflects lack of understanding about MDX on my part. Any pointers to quality introductory material would be appreciated.
It's important to understand that in MDX you are building sets of members on each axis, and not specifying column names like a tabular rowset. You are describing a 2-dimensional grid of results, not a linear rowset. If you imagine each dimension as a table, the member set is the set of unique values from a single column in that table.
When you choose a Measure as the member (as in your first example), it looks as if you're selecting from a table, so it's easy to misunderstand. When you choose a Dimension, you get many members, and a cross-join between the rows and columns (which is sparse in this case because the names and genders are 1-to-1).
So, you could crossjoin these two dimensions on a single axis, and then filter out the null cells:
SELECT
event_count ON 0,
TOPCOUNT(
NonEmptyCrossJoin(name.children, gender.children),
10,
event_count) ON 1
FROM
events
Which should give you results that have a single column (event_count) and 10 rows, where each row is composed of the tuple (name, gender).
I hope that sets you on the right path, and please feel free to ask you want me to clarify.
For general introductory material, I think the book "MDX Solutions" is a good place to start:
http://www.amazon.ca/MDX-Solutions-Microsoft-Analysis-Services/dp/0471748080/
For an online MDX introductory material, you can have a look to this gentle introduction that presents the main MDX concepts.
I have three tables like this:
Person table:
person_id | name | dob
--------------------------------
1 | Naveed | 1988
2 | Ali | 1985
3 | Khan | 1987
4 | Rizwan | 1984
Address table:
address_id | street | city | state | country
----------------------------------------------------
1 | MAJ Road | Karachi | Sindh | Pakistan
2 | ABC Road | Multan | Punjab | Pakistan
3 | XYZ Road | Riyadh | SA | SA
Person_Address table:
person_id | address_id
----------------------
1 | 1
2 | 2
3 | 3
Now I want to get all records of Person_Address table but also with their person and address records like this by one query:
person_id| name | dob | address_id | street | city | state | country
----------------------------------------------------------------------------------
1 | Naveed | 1988 | 1 | MAJ Road | Karachi | Sindh | Pakistan
2 | Ali | 1985 | 2 | ABC Road | Multan | Punjab | Pakistan
3 | Khan | 1987 | 3 | XYZ Road | Riyadh | SA | SA
How it is possible using zend? Thanks
The reference guide is the best starting point to learn about Zend_Db_Select. Along with my example below, of course:
//$db is an instance of Zend_Db_Adapter_Abstract
$select = $db->select();
$select->from(array('p' => 'person'), array('person_id', 'name', 'dob'))
->join(array('pa' => 'Person_Address'), 'pa.person_id = p.person_id', array())
->join(array('a' => 'Address'), 'a.address_id = pa.address_id', array('address_id', 'street', 'city', 'state', 'country'));
It's then as simple as this to fetch a row:
$db->fetchRow($select);
In debugging Zend_Db_Select there's a clever trick you can use - simply print the select object, which in turn invokes the toString method to produce SQl:
echo $select; //prints SQL
I'm not sure if you're looking for SQL to do the above, or code using Zend's facilities. Given the presence of "sql" and "joins" in the tags, here's the SQL you'd need:
SELECT p.person_id, p.name, p.dob, a.address_id, street, city, state, country
FROM person p
INNER JOIN Person_Address pa ON pa.person_id = p.person_id
INNER JOIN Address a ON a.address_id = pa.address_id
Bear in mind that the Person_Address tells us that there's a many-to-many relationship between a Person and an Address. Many Persons may share an Address, and a Person may have more than one address.
The SQL above will show ALL such relationships. So if Naveed has two Address records, you will have two rows in the result set with person_id = 1.
I need to run a query like:
SELECT p.id, p.name,
(SELECT name
FROM sites s
WHERE s.id = p.site_id) AS site_list
FROM publications p
But I'd like the sub-select to return a comma separated list, instead of a column of data. Is this even possible, and if so, how?
You can use GROUP_CONCAT to perform that, e.g. something like
SELECT p.id, p.name, GROUP_CONCAT(s.name) AS site_list
FROM sites s
INNER JOIN publications p ON(s.id = p.site_id)
GROUP BY p.id, p.name;
Now only I came across this situation and found some more interesting features around GROUP_CONCAT. I hope these details will make you feel interesting.
simple GROUP_CONCAT
SELECT GROUP_CONCAT(TaskName)
FROM Tasks;
Result:
+------------------------------------------------------------------+
| GROUP_CONCAT(TaskName) |
+------------------------------------------------------------------+
| Do garden,Feed cats,Paint roof,Take dog for walk,Relax,Feed cats |
+------------------------------------------------------------------+
GROUP_CONCAT with DISTINCT
SELECT GROUP_CONCAT(TaskName)
FROM Tasks;
Result:
+------------------------------------------------------------------+
| GROUP_CONCAT(TaskName) |
+------------------------------------------------------------------+
| Do garden,Feed cats,Paint roof,Take dog for walk,Relax,Feed cats |
+------------------------------------------------------------------+
GROUP_CONCAT with DISTINCT and ORDER BY
SELECT GROUP_CONCAT(DISTINCT TaskName ORDER BY TaskName DESC)
FROM Tasks;
Result:
+--------------------------------------------------------+
| GROUP_CONCAT(DISTINCT TaskName ORDER BY TaskName DESC) |
+--------------------------------------------------------+
| Take dog for walk,Relax,Paint roof,Feed cats,Do garden |
+--------------------------------------------------------+
GROUP_CONCAT with DISTINCT and SEPARATOR
SELECT GROUP_CONCAT(DISTINCT TaskName SEPARATOR ' + ')
FROM Tasks;
Result:
+----------------------------------------------------------------+
| GROUP_CONCAT(DISTINCT TaskName SEPARATOR ' + ') |
+----------------------------------------------------------------+
| Do garden + Feed cats + Paint roof + Relax + Take dog for walk |
+----------------------------------------------------------------+
GROUP_CONCAT and Combining Columns
SELECT GROUP_CONCAT(TaskId, ') ', TaskName SEPARATOR ' ')
FROM Tasks;
Result:
+------------------------------------------------------------------------------------+
| GROUP_CONCAT(TaskId, ') ', TaskName SEPARATOR ' ') |
+------------------------------------------------------------------------------------+
| 1) Do garden 2) Feed cats 3) Paint roof 4) Take dog for walk 5) Relax 6) Feed cats |
+------------------------------------------------------------------------------------+
GROUP_CONCAT and Grouped Results
Assume that the following are the results before using GROUP_CONCAT
+------------------------+--------------------------+
| ArtistName | AlbumName |
+------------------------+--------------------------+
| Iron Maiden | Powerslave |
| AC/DC | Powerage |
| Jim Reeves | Singing Down the Lane |
| Devin Townsend | Ziltoid the Omniscient |
| Devin Townsend | Casualties of Cool |
| Devin Townsend | Epicloud |
| Iron Maiden | Somewhere in Time |
| Iron Maiden | Piece of Mind |
| Iron Maiden | Killers |
| Iron Maiden | No Prayer for the Dying |
| The Script | No Sound Without Silence |
| Buddy Rich | Big Swing Face |
| Michael Learns to Rock | Blue Night |
| Michael Learns to Rock | Eternity |
| Michael Learns to Rock | Scandinavia |
| Tom Jones | Long Lost Suitcase |
| Tom Jones | Praise and Blame |
| Tom Jones | Along Came Jones |
| Allan Holdsworth | All Night Wrong |
| Allan Holdsworth | The Sixteen Men of Tain |
+------------------------+--------------------------+
USE Music;
SELECT ar.ArtistName,
GROUP_CONCAT(al.AlbumName)
FROM Artists ar
INNER JOIN Albums al
ON ar.ArtistId = al.ArtistId
GROUP BY ArtistName;
Result:
+------------------------+----------------------------------------------------------------------------+
| ArtistName | GROUP_CONCAT(al.AlbumName) |
+------------------------+----------------------------------------------------------------------------+
| AC/DC | Powerage |
| Allan Holdsworth | All Night Wrong,The Sixteen Men of Tain |
| Buddy Rich | Big Swing Face |
| Devin Townsend | Epicloud,Ziltoid the Omniscient,Casualties of Cool |
| Iron Maiden | Somewhere in Time,Piece of Mind,Powerslave,Killers,No Prayer for the Dying |
| Jim Reeves | Singing Down the Lane |
| Michael Learns to Rock | Eternity,Scandinavia,Blue Night |
| The Script | No Sound Without Silence |
| Tom Jones | Long Lost Suitcase,Praise and Blame,Along Came Jones |
+------------------------+----------------------------------------------------------------------------+
Instead of using group concat() you can use just concat()
Select concat(Col1, ',', Col2) as Foo_Bar from Table1;
edit this only works in mySQL; Oracle concat only accepts two arguments. In oracle you can use something like select col1||','||col2||','||col3 as foobar from table1;
in sql server you would use + instead of pipes.
In my case i have to concatenate all the account number of a person who's mobile number is unique. So i have used the following query to achieve that.
SELECT GROUP_CONCAT(AccountsNo) as Accounts FROM `tblaccounts` GROUP BY MobileNumber
Query Result is below:
Accounts
93348001,97530801,93348001,97530801
89663501
62630701
6227895144840002
60070021
60070020
60070019
60070018
60070017
60070016
60070015