I have 2 tables - patients, and issuers.
I with to extract entire patients table along with issuer_name from patients and issuers table. Optionally there might be no issuer of patient identifier.
If i do:
select * from patients, issuer_name where patients.issuer_of_patient_identifier=issuer.issuer_id doesn't return anything in case for the corresponding patient table row issuer_of_patient_identifier is NULL.
How do i accomplish this?
mysql> describe patients;
+------------------------------+--------------+------+-----+-------------------+-----------------------------+
| Field | Type | Null | Key | Default | Extra |
+------------------------------+--------------+------+-----+-------------------+-----------------------------+
| patient_id | int(11) | NO | PRI | NULL | auto_increment |
| patient_identifier | varchar(64) | YES | MUL | NULL | |
| issuer_of_patient_identifier | int(11) | YES | MUL | NULL | |
| medical_record_locator | varchar(64) | YES | | NULL | |
| patient_name | varchar(128) | NO | MUL | NULL | |
| birth_date | datetime | YES | | NULL | |
| deceased_date | datetime | YES | | NULL | |
| gender | varchar(16) | YES | | NULL | |
| ethnicity | varchar(45) | YES | | NULL | |
| date_created | datetime | NO | | CURRENT_TIMESTAMP | |
| last_update_date | datetime | YES | | NULL | on update CURRENT_TIMESTAMP |
| last_updated_by | varchar(128) | NO | | NULL | |
+------------------------------+--------------+------+-----+-------------------+-----------------------------+
12 rows in set (0.00 sec)
mysql> describe issuers;
+------------------+--------------+------+-----+-------------------+-----------------------------+
| Field | Type | Null | Key | Default | Extra |
+------------------+--------------+------+-----+-------------------+-----------------------------+
| issuer_id | int(11) | NO | PRI | NULL | auto_increment |
| issuer_name | varchar(64) | NO | MUL | NULL | |
| issuer_uid | varchar(128) | YES | | NULL | |
| issuer_uid_type | varchar(64) | YES | | NULL | |
| date_created | datetime | NO | | CURRENT_TIMESTAMP | |
| last_update_date | datetime | YES | | NULL | on update CURRENT_TIMESTAMP |
| last_updated_by | varchar(128) | NO | | NULL | |
+------------------+--------------+------+-----+-------------------+-----------------------------+
The query is
select * from patients
LEFT JOIN issuer_name ON
patients.issuer_of_patient_identifier = issuer.issuer_id
Without joins:
select * from patients, issuer_name
where patients.issuer_of_patient_identifier = issuer.issuer_id
OR patients.issuer_of_patient_identifier IS NULL
Never use commas in the FROM clause. Always use proper, explicit JOIN syntax. Avoid tutorials that use commas. Challenge instructors that show examples with them.
You want a LEFT JOIN:
select *
from patients p left join
issuer_name i
on p.issuer_of_patient_identifier = i.issuer_id;
Related
I have the following 2 tables (student and attendance):
mysql> describe student;
+----------------------+--------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+----------------------+--------------+------+-----+---------+----------------+
| student_id | int(11) | NO | PRI | NULL | auto_increment |
| student_email | varchar(255) | YES | | NULL | |
| student_phone_number | varchar(255) | YES | | NULL | |
| parent_first_name | varchar(255) | NO | | NULL | |
| parent_last_name | varchar(255) | NO | | NULL | |
| parent_email | varchar(255) | NO | | NULL | |
| parent_phone_number | varchar(255) | NO | | NULL | |
| first_name | varchar(255) | NO | | NULL | |
| last_name | varchar(255) | NO | | NULL | |
| days_absent | int(11) | YES | | NULL | |
| days_tardy | int(11) | YES | | NULL | |
| class_id | int(11) | NO | MUL | NULL | |
+----------------------+--------------+------+-----+---------+----------------+
mysql> describe attendance;
+-----------------+------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-----------------+------------+------+-----+---------+-------+
| student_id | int(11) | NO | PRI | NULL | |
| class_id | int(11) | NO | PRI | NULL | |
| attendance_date | date | NO | PRI | NULL | |
| absent | tinyint(1) | YES | | NULL | |
| tardy | tinyint(1) | YES | | NULL | |
| note | text | YES | | NULL | |
+-----------------+------------+------+-----+---------+-------+
I want to check the attendance and email of all the children who are absent or tardy for the day. Is there a SQL statement I can use that can, for example, select the students from attendance with an absent/tardy value = 1, then using that student_id specified in the attendance table, pull all the student info from the student table where attendance.student_id = student.student_id?
just try exists
select student_email,student_phone_number from student std
where exists(
select 1 from attendance atd where std.student_id = atd.student_id
and (atd.absent =1 or atd.tardy =1)
)
just make sure you select all the info from student table and exists all the filter in attendance talbe. the condition is student_id.
Also if you need info from attendance talbe, then use join.
I have two databases.
One is called INFO with three tables (Stories, Comments, Replies)
Stories has the following fields
+--------------+----------------+------+-----+---------------------+-----------------------------+
| Field | Type | Null | Key | Default | Extra |
+--------------+----------------+------+-----+---------------------+-----------------------------+
| storyID | int(11) | NO | PRI | NULL | |
| originalURL | varchar(500) | YES | | NULL | |
| originalDate | timestamp | NO | | CURRENT_TIMESTAMP | on update CURRENT_TIMESTAMP |
| numDiggs | int(11) | YES | | NULL | |
| numComments | int(11) | YES | | NULL | |
| diggURL | varchar(500) | YES | | NULL | |
| rating | varchar(50) | YES | | NULL | |
| title | varchar(200) | YES | | NULL | |
| summary | varchar(10000) | YES | | NULL | |
| uploaderID | varchar(50) | YES | | NULL | |
| imageURL | varchar(500) | YES | | NULL | |
| category1 | varchar(50) | YES | | NULL | |
| category2 | varchar(50) | YES | | NULL | |
| uploadDate | timestamp | NO | | 0000-00-00 00:00:00 | |
| num | int(11) | YES | | NULL | |
+--------------+----------------+------+-----+---------------------+-----------------------------+
Another database is called Data with one table (User). Fields shown below:
+-------------------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------------------+-------------+------+-----+---------+-------+
| userID | varchar(50) | NO | PRI | NULL | |
| numStories | int(11) | YES | | NULL | |
| numComments | int(11) | YES | | NULL | |
| numReplies | int(11) | YES | | NULL | |
| numStoryDiggs | int(11) | YES | | NULL | |
| numCommentReplies | int(11) | YES | | NULL | |
| numReplyDiggs | int(11) | YES | | NULL | |
| numStoryComments | int(11) | YES | | NULL | |
| numStoryReplies | int(11) | YES | | NULL | |
+-------------------+-------------+------+-----+---------+-------+
User.userID is full of thousands of unique names. All other fields are currently NULL. The names in User.userID correspond to the names in Stories.uploaderID.
I need to, for each userID in User, count the number of stories uploaded from (i.e. num) Stories for the corresponding name and insert this value into User.numStories.
The query which I have come up with (which produces an error) is:
INSERT INTO DATA.User(numStories)
SELECT count(num)
FROM INFO.Stories
WHERE INFO.Stories.uploaderID=DATA.User.userID;
The error I get when running this query is
Unknown column 'DATA.User.userID' in 'where clause'
Sorry if this is badly explained. I will try and re-explain if need be.
You aren't creating new entries in the User table, you're updating existing ones. Hence, insert isn't the right syntax here, but rather update:
UPDATE DATA.User u
JOIN (SELECT uploaderID, SUM(num) AS sumNum
FROM INFO.Stories
GROUP BY uploadedID) i ON i.uploaderID = u.userID
SET numStories = sumNum
EDIT:
Some clarification, as requested in the comments.
The inner query sums the num in Stories per uploaderId. The updates statement updates the numStories in User the the calculated sum of the inner query of the matching id.
I have three tables, emails, person_details and data_providers. Basically all of my users id, email, and current assigned data_providers_id are stored in the emails table.
The second table, person_details contains demographic information collected by multiple data providers, each row identified by an emails_id that is relational to the emails.id data_providers_id that is relational to the third table data_providers.id
The third table, data_providers contains each of my data providers id, name, and precedence.
Basically, a users information could be collected from multiple sources, and I need to UPDATE emails set data_providers_id = based on a select that would JOIN the person_details table and the data_providers table sorting by data_providers.precedence DESC then person_details.import_date ASC and use the first value (highest precedence, then oldest import_date).
I was trying to build the query, but my subquery is returning more than one row. This query is a little over my head, hoping someone more experienced with complex queries might be able to point me in the right direction.
UPDATE emails
SET emails.data_providers_id =
SELECT person_details.data_providers_id
FROM person_details
LEFT JOIN data_providers ON person_details.data_providers_id = data_providers.id
ORDER BY data_providers.percent_payout ASC, person_details.import_date ASC ;
Here are some details about the three tables if this helps. Any guidance would be MUCH appreciated. Thanks in advance :)
emails table:
+-------------------+---------------------+------+-----+---------------------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-------------------+---------------------+------+-----+---------------------+----------------+
| id | int(11) unsigned | NO | PRI | NULL | auto_increment |
| data_providers_id | tinyint(3) unsigned | NO | MUL | NULL | |
| email | varchar(255) | NO | UNI | NULL | |
+-------------------+---------------------+------+-----+---------------------+----------------+
person_details:
+-------------------+---------------------+------+-----+---------------------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------------------+---------------------+------+-----+---------------------+-------+
| emails_id | int(11) unsigned | NO | PRI | NULL | |
| data_providers_id | tinyint(3) unsigned | NO | PRI | NULL | |
| fname | varchar(255) | YES | | NULL | |
| lname | varchar(255) | YES | | NULL | |
| address_line1 | text | YES | | NULL | |
| address_line2 | text | YES | | NULL | |
| city | varchar(255) | YES | | NULL | |
| state | varchar(2) | YES | | NULL | |
| zip5 | varchar(5) | YES | | NULL | |
| zip4 | varchar(4) | YES | | NULL | |
| home_phone | varchar(10) | YES | | NULL | |
| mobile_phone | varchar(10) | YES | | NULL | |
| work_phone | varchar(10) | YES | | NULL | |
| dob | date | YES | | NULL | |
| gender | varchar(1) | YES | | NULL | |
| ip_address | varchar(15) | NO | | NULL | |
| source | varchar(255) | NO | | NULL | |
| optin_datetime | datetime | NO | MUL | NULL | |
| import_date | timestamp | NO | | 0000-00-00 00:00:00 | |
+-------------------+---------------------+------+-----+---------------------+-------+
data_providers table:
+-----------------+---------------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-----------------+---------------------+------+-----+---------+----------------+
| id | tinyint(3) unsigned | NO | PRI | NULL | auto_increment |
| name | varchar(255) | NO | | NULL | |
| precedence | int(2) | YES | | 0 | |
+-----------------+---------------------+------+-----+---------+----------------+
To use a SELECT as an expression you have to put it in parentheses. And to get the first value, use LIMIT 1:
UPDATE emails
SET emails.data_providers_id = (
SELECT person_details.data_providers_id
FROM person_details
LEFT JOIN data_providers ON person_details.data_providers_id = data_providers.id
WHERE person_details.emails_id = emails.id
ORDER BY data_providers.percent_payout ASC, person_details.import_date ASC
LIMIT 1) ;
I am trying to write a MySQL query that gives me results of Organisation Name, its Post Code, any Events that belong to the Organisation and the Post Code of that Event. I've tried all sorts of of join, join and select combinations to no avail. Is this something that is possible ? (I could have a separate table for Org Address and Event Address but it seems like it should be possible to use just one table)
My table structures:
mysql> DESCRIBE cc_organisations;
+-------------+------------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-------------+------------------+------+-----+---------+----------------+
| id | int(10) unsigned | NO | PRI | NULL | auto_increment |
| user_id | int(10) unsigned | NO | MUL | NULL | |
| type | enum('C','O') | YES | | NULL | |
| name | varchar(150) | NO | MUL | NULL | |
| description | text | YES | | NULL | |
+-------------+------------------+------+-----+---------+----------------+
5 rows in set (0.00 sec)
mysql> DESCRIBE cc_events;
+-------------+------------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-------------+------------------+------+-----+---------+----------------+
| id | int(10) unsigned | NO | PRI | NULL | auto_increment |
| org_id | int(10) unsigned | NO | MUL | NULL | |
| name | varchar(150) | NO | MUL | NULL | |
| start_date | int(11) | NO | MUL | NULL | |
| end_date | int(11) | YES | MUL | NULL | |
| start_time | int(11) | NO | | NULL | |
| end_time | int(11) | NO | | NULL | |
| description | text | YES | | NULL | |
+-------------+------------------+------+-----+---------+----------------+
8 rows in set (0.00 sec)
mysql> DESCRIBE cc_addresses;
+--------------+------------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+--------------+------------------+------+-----+---------+----------------+
| id | int(10) unsigned | NO | PRI | NULL | auto_increment |
| org_id | int(10) unsigned | YES | MUL | NULL | |
| event_id | int(10) unsigned | YES | MUL | NULL | |
| post_code | varchar(7) | NO | MUL | NULL | |
| address_1 | varchar(100) | NO | | NULL | |
| address_2 | varchar(100) | YES | | NULL | |
| town | varchar(50) | NO | | NULL | |
| county | varchar(50) | NO | | NULL | |
| email | varchar(150) | NO | | NULL | |
| phone | int(11) | YES | | NULL | |
| mobile | int(11) | YES | | NULL | |
| website_uri | varchar(150) | YES | | NULL | |
| facebook_uri | varchar(250) | YES | | NULL | |
| twitter_uri | varchar(250) | YES | | NULL | |
+--------------+------------------+------+-----+---------+----------------+
14 rows in set (0.00 sec)
select o.Name, oAddress.PostCode, e.Name, eAddress.PostCode
from cc_organisations o
inner join cc_addresses oAddress on oAddress.org_id = o.id
left outer join cc_events e on e.org_id=o.id
inner join cc_addresses eAddress on eAddress.event_id = e.id
SELECT cco.name as OrgName, cca.post_code as OrgPostCode, cce.id,
cce.org_id, cce.name, cce.start_date, cce.end_date, cce.start_time,
cce.end_time, cce.description
FROM cc_events cce, cc_addresses cca, cc_organisations cco
WHERE cca.event_id = cce.id AND cco.id=cce.org_id
ORDER BY cce.start_date
LIMIT 50;
You can change your sort and limit, I just added those in because I don't know how big your DB is... You may even be able to get away with:
SELECT cco.name as OrgName, cca.post_code as OrgPostCode, cce.*
FROM cc_events cce, cc_addresses cca, cc_organisations cco
WHERE cca.event_id = cce.id AND cco.id=cce.org_id
ORDER BY cce.start_date LIMIT 50;
But im not 100% sure if the 2nd query will bum out or not.
Your address table has the post codes in it; but it also has an organization id and event id foreign keys. We only need to check the event_id from the address table because any event will belong to an organization.
Address's Event matched Event ID
Event's Organization matched Organization ID
I have the following query:
SELECT DISTINCT `movies_manager_movie`.`id`,
`movies_manager_movie`.`title`,
`movies_manager_movie`.`original_title`,
`movies_manager_movie`.`synopsis`,
`movies_manager_movie`.`keywords`,
`movies_manager_movie`.`release_date`,
`movies_manager_movie`.`rating`,
`movies_manager_movie`.`poster_web_url`,
`movies_manager_movie`.`has_poster`,
`movies_manager_movie`.`number`,
`movies_manager_movie`.`has_sources`,
`movies_manager_movie`.`season_id`,
`movies_manager_movie`.`created`,
`movies_manager_movie`.`updated`,
`movies_manager_moviecache`.`activity_name`
FROM `movies_manager_movie`
LEFT OUTER JOIN `movies_manager_moviecache` ON (`movies_manager_movie`.`id` = `movies_manager_moviecache`.`movie_id`)
WHERE (`movies_manager_movie`.`has_sources` = 1
AND (`movies_manager_moviecache`.`team_member_id` IN (
SELECT U0.`id` FROM `movies_manager_movieteammember` U0
INNER JOIN `movies_manager_movieteammemberactivity` U1 ON (U0.`id` = U1.`team_member_id`)
WHERE U1.`movie_id` = 3588 )
AND `movies_manager_movie`.`number` IS NULL
)
AND NOT (`movies_manager_movie`.`id` = 3588 ))
ORDER BY `movies_manager_moviecache`.`activity_name` DESC LIMIT 3;
This query can take up to 3 seconds and I'm very surprise since I got indexes everywhere and no more than 35 rows in each of my MyIsam tables, using the latest MySQL version.
I cached everything I could but I have at least to run this one 20000 times every day, which is approximately 16 h of waiting for loading. And I'm pretty sure none of my user (nor Google Bot) appreciate a 4 secondes waiting time for each page loading.
What could I do to make it faster ?
I thought about duplicating field from movie to moviecache since the all purpose of movie cache is to denormalize to complex join already.
I tried inlining the subquery to a list of ID but it surprisingly doubled the time of the query.
Tables:
+----------------+--------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+----------------+--------------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| title | varchar(120) | NO | UNI | NULL | |
| original_title | varchar(120) | YES | | NULL | |
| synopsis | longtext | YES | | NULL | |
| keywords | varchar(120) | YES | | NULL | |
| release_date | date | YES | | NULL | |
| rating | int(11) | NO | | NULL | |
| poster_web_url | varchar(255) | YES | | NULL | |
| has_poster | tinyint(1) | NO | | NULL | |
| number | int(11) | YES | | NULL | |
| season_id | int(11) | YES | MUL | NULL | |
| created | datetime | NO | | NULL | |
| updated | datetime | NO | | NULL | |
| has_sources | tinyint(1) | NO | | NULL | |
+----------------+--------------+------+-----+---------+----------------+
+---------------------+--------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+---------------------+--------------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| name | varchar(120) | NO | UNI | NULL | |
| biography | longtext | YES | | NULL | |
| birth_date | date | YES | | NULL | |
| picture_web_url | varchar(255) | YES | | NULL | |
| allocine_link | varchar(255) | YES | | NULL | |
| created | datetime | NO | | NULL | |
| updated | datetime | NO | | NULL | |
| has_picture | tinyint(1) | NO | | NULL | |
| biography_linkyfied | longtext | YES | | NULL | |
+---------------------+--------------+------+-----+---------+----------------+
+----------------+--------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+----------------+--------------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| movie_id | int(11) | NO | MUL | NULL | |
| tag_slug | varchar(100) | YES | MUL | NULL | |
| team_member_id | int(11) | YES | MUL | NULL | |
| cast_rank | int(11) | YES | | NULL | |
| activity_name | varchar(30) | YES | MUL | NULL | |
+----------------+--------------+------+-----+---------+----------------+
Mysql tells me it's a slow query:
# Query_time: 3 Lock_time: 0 Rows_sent: 9 Rows_examined: 454128
Move movies_manager_movieteammemberactivity and movies_manager_movieteammember to your main join statement (so that you're doing a left outer between movies_manager_movie and the inner join product of the other 3 tables). This should speed up your query considerably.
Try this:
SELECT `movies_manager_movie`.`id`,
`movies_manager_movie`.`title`,
`movies_manager_movie`.`original_title`,
`movies_manager_movie`.`synopsis`,
`movies_manager_movie`.`keywords`,
`movies_manager_movie`.`release_date`,
`movies_manager_movie`.`rating`,
`movies_manager_movie`.`poster_web_url`,
`movies_manager_movie`.`has_poster`,
`movies_manager_movie`.`number`,
`movies_manager_movie`.`has_sources`,
`movies_manager_movie`.`season_id`,
`movies_manager_movie`.`created`,
`movies_manager_movie`.`updated`,
(
SELECT `movies_manager_moviecache`.`activity_name`
FROM `movies_manager_moviecache`
WHERE (`movies_manager_movie`.`id` = `movies_manager_moviecache`.`movie_id`
AND (`movies_manager_moviecache`.`team_member_id` IN (
SELECT U0.`id` FROM `movies_manager_movieteammember` U0
INNER JOIN `movies_manager_movieteammemberactivity` U1 ON (U0.`id` = U1.`team_member_id`)
WHERE U1.`movie_id` = 3588 )
AND `movies_manager_movie`.`number` IS NULL
) ) LIMIT 1) AS `activity_name`
FROM `movies_manager_movie`
WHERE (`movies_manager_movie`.`has_sources` = 1
AND NOT (`movies_manager_movie`.`id` = 3588 ))
ORDER BY `activity_name` DESC
LIMIT 3;
Let me know how that performs