I have two MySQL Queries that i am trying to use to balance the db and find issues.
Query 1 for advance totals 286940.99 and query 2 totals 288645.3 which is 1,704.31 different (the advance unallocated is also wrong).
The issue I have is they are both summing the same column the only diffeence been that query 2 has a left join to join another table. The left Join should not affect the primary table at all.
Here are my queries
Query 1
SELECT sum(advance) as advance, sum(advance_unallocated) as advance_unallocated FROM `deals`
Query 2
SELECT
pb.id as pbid,
d.id as did,
sum(d.advance) as advance,
sum(d.advance_unallocated) as advance_unallocated,
sum(pb.payments) as pb_payment,
sum(pb.payments) - sum(d.advance) - sum(d.advance_unallocated) as diff,
pb.payment_method as p_payment_method
FROM `deals` d
LEFT OUTER JOIN `payment_balance` pb on d.id = pb.link_id and pb.table_name = 'deals'
This happens because LEFT JOIN returns not the [0, 1] number of rows as you originally thought but all the rows that match the join conditions, or a row filled NULLs otherwise.
In your particular case there are 1 or more rows that match join condition "unexpectedly".
Related
I am trying to write an SQL query which will select records of a student within 3 tables that have the same column_I'd.
This is what I wrote but the the records selected are not accurate:
select
Nov_DEC_billing.*,
Nov_DEC_students_portfolio.*,
admission_form.academic_year
from
Nov_DEC_billing,
Nov_DEC_student_portfolio,
admission_form
where
Nov_DEC_billing.ID = Nov_DEC_student_portfolio.ID=admission_form.ID
AND
admission_form.Program ='Nov/dec'
I get a records selected alright but its not accurate. Please what's the right way to join 3 tables that share the same column_id.???
Use JOIN in your query
SELECT b.*, p.*, a.academic_year
FROM Nov_DEC_billing b
JOIN Nov_DEC_student_portfolio p ON p.id = b.id
JOIN admission_form a ON a.id = b.id
WHERE a.Program='Nov/dec'
You need to join tables something like this:
SELECT Nov_DEC_billing.*,
Nov_DEC_students_portfolio.*,
admission_form.academic_year
FROM Nov_DEC_billing AS ndb,
LEFT JOIN Nov_DEC_student_portfolio AS ndsp ON ndsp.ID=ndb.ID,
LEFT JOIN admission_form AS af ON af.ID=ndb.ID
WHERE af.Program='Nov/dec'
You should join all the tables to a single one.
What you will is join all the tables to a single one and then select from it.
Since you have 2 tables you should first join 2 and then join another one on the result.
See here left join example for the exact syntax.
Nov_DEC_billing.ID=Nov_DEC_student_portfolio.ID=admission_form.ID
doesn't do what you expect. It takes the first part, Nov_DEC_billing.ID=Nov_DEC_student_portfolio.ID and evaluates it. If the values match, that part becomes a 1, if they don't match, it becomes 0. Then the 0 or the 1 is compared against admission_form.ID. That is very likely to give strange results.
So you'd have to split that into:
Nov_DEC_billing.ID=Nov_DEC_student_portfolio.ID
AND Nov_DEC_student_portfolio.ID=admission_form.ID
Or just use explicit join syntax, as the others already advised (and which I do too). That forces you to split this anyway.
How can I unite two select statement in one table result?
For instance in the first table I want to get everything however on my 2nd table I only want the corel name that is equal to the corel_id and id of my 2nd table?
SELECT *
FROM garage
UNION
SELECT c.name
FROM corel as c
WHERE EXISTS (SELECT 1 FROM garage as g WHERE c.id = g.corel_id
I tried to execute this but this did not work. Is this right? or is there a better way to do this?
Sorry newbie here.
UPDATE EXPECTED RESULT :
https://anotepad.com/notes/b6662w
Give this a try:
SELECT g.*, c.name
FROM garage g
LEFT JOIN corel c
ON c.id = g.corel_id
Matching two tables in a database is called a join. An inner join, the default, returns only the rows that match from both tables.
A left join returns all the rows from the first table whether or not they match the second, and any data from the second table that matches. The right join does the inverse, returning only non-matching data from the second table. There is also the full join that returns all data regardless of match.
A join statement is what you need. A join puts columns from multiple tables into rows together based in the matching conditions in the where clause.
A union requires 2 or more queries to have the same columns. The union puts the sets of rows together into a longer set or rows.
I need to fetch data from 5 tables(all columns of each table) all have FK, which is PK of single table.
But some of the tables may have record may be empty.If data is present on the respective column/table it should return otherwise null/default value
There is one to many and one to one relations on the child tables with parent table.
I have tried so far
- UNION which has concern of same number of columns
- CROSS JOIN not returning any data
- SELECT ALL_COLUMN FROM ALL_TABLE WHERE TABLE.FK=ID Not returning any data
- LEFT JOIN working for 2 tables but not more than that
SELECT A.GENDER, B.BLOCKED_USER FROM t_macroworld_registration AS A
LEFT JOIN t_macroworld_blacklist AS B ON 1=1 WHERE A.ID=15
What are the possible ways I can implement this in a view in MySQL.
Outer join operations are the normative pattern...
SELECT ...
FROM a
LEFT JOIN b ON b.a_id = a.id
LEFT JOIN c ON c.a_id = a.id
LEFT JOIN d ON d.a_id = a.id
WHERE a.id = 15
It's important for the predicates on the outer joined tables to be in the ON clause and not the WHERE clause. If there's any predicate in the WHERE clause requires that a value from one of the outer joined tables be non-NULL, that will negate the "outerness" of the join, making it into an inner join.
The "big rock" problem with this the result when there are more than one matching rows in b, c and d. If there's five rows from b that match, and three rows from c that match, and two rows from b that match, it's going to look like a lot of duplicates. (5x3x2 = 30 rows to be returned, with a lot of duplicated data on those rows.)
Finally I have solved It,
I broke the whole thing into many select query based on FK from each table, so number of additional row returns and mapping has become easy.
Who ever is getting this kind of problem, if it is possible then break it into many select query instead of one.
SELECT
w.id,w.name,a.address,i.name,i.quantity
FROM
warehouse w
LEFT JOIN address AS a ON a.warehouse_id = w.id
LEFT JOIN item AS i ON i.warehouse_id = w.id
LEFT JOIN order AS o ON o.item_id = i.id
WHERE
w.id = 1
GROUP BY 1,2,3,4;
Will give you an overview of your stock and orders for your warehouses. This will also duplicate some results.
Assuming 2 warehouses, 1 address for each, 3 items per warehouse, 2 orders by item = 2 * 3 * 2 = 12 lines
I recommend adding your LEFT JOIN stage by stage and visualizing the result for each stage. You'll quickly understand why lines are multiplying.
Note the usage of foreign keys and ids in the tables to link the tables.
Good luck
Given the following query…
SELECT DISTINCT *
FROM PAS_Post
WHERE post_user_id = 21
GROUP BY post_post_id
UNION
SELECT DISTINCT PAS_Post.*
FROM PAS_Follow LEFT JOIN PAS_Post ON (
PAS_Follow.folw_followed_user_id = PAS_Post.post_user_id
)
WHERE PAS_Follow.folw_follower_user_id = 21
GROUP BY post_post_id
ORDER BY post_posted_date DESC
I always get a row in the results that is just NULL's, unfortunately I need to preserve some NULL values in the data as the Post's table (PAS_Post) holds different types of information.
Can anyone steer me in the right direction to get rid of this null row.
I do not want or need the last row here
You're using a (left) outer join in the second part of the UNION, so any cases that do not satisfy the join criteria will result in data from the table on the left of the join (PAS_Follow), but NULL in every column of the table on the right of the join (PAS_Post); the subsequent selection only of columns from the latter table results in the NULL rows that you observe. Therefore, the simplest solution is to use an inner join (that completely excludes records where the join criteria is not met).
However, in your case, it appears that your query can be greatly simplified by simply using two possible conditions in a filter on the joined tables rather than a UNION:
SELECT p.*
FROM PAS_Post AS p
JOIN PAS_Follow AS f ON f.folw_followed_user_id = p.post_user_id
WHERE p.post_user_id = 21
OR f.folw_follower_user_id = 21
ORDER BY p.post_posted_date DESC
I have excluded the GROUP BY clause on the assumption that post_post_id is the primary key (or at very least is UNIQUE) in your PAS_Post table. If that assumption is incorrect, you may want to reintroduce it—but beware that MySQL will indeterminately select the values that will be returned from each group.
I need a query. I'm trying to sum of one field with joined tables. Some records not in second table. So this records sum should be zero. But the query only sum the records which are in the second table.
select s.*,sum(sd.fiyat) as konak from fuar_sozlesme1 s
left outer join fuar_sozlesme1_detay sd on (sd.sozlesme_id = s.id)
------EDIT-------
I added group by into the query and solved my problem. Here is the new ;
select s.*,sum(sd.fiyat) as konak from fuar_sozlesme1 s
left outer join fuar_sozlesme1_detay sd on (sd.sozlesme_id = s.id)
group by sd.sozlesme_id
I thinik you need to use IFNULL(sd.fiyat,0) instead of sd.fiyat to get zeros for the NULL values coming from the second table because of the LEFT JOIN like so:
SELECT s.*, SUM(IFNULL(sd.fiyat, 0)) as konak
FROM fuar_sozlesme1 s
LEFT OUTER JOIN fuar_sozlesme1_detay sd ON sd.sozlesme_id = s.id
GROUP BY s.someFields
Here is a simple example, you may help: http://sqlfiddle.com/#!2/41481/1
This is an old thread, but I spent a couple of hours trying to solve the same issue.
My query has two joins, a filter and a SUM function. I'm no SQL expert, but this helped me achieve the desired result of still showing a result even if the joined table had no rows to sum.
The key for me in order to show results even if the sum was totaling nothing, was the GROUP BY. I'm still not 100% sure why.
The two types of joins were chosen based on this article - MySQL Multiple Joins in one query?
SELECT registrations.reg_active, registrations.team_id, registrations.area_id, registrations.option_id, registrations.reg_fund_goal, registrations.reg_type, registrations.reg_fee_paid, registrations.reg_has_avatar, users.user_name, users.user_email, users.user_phone, users.user_zip, users.user_age, users.user_gender, users.user_active, SUM(IFNULL(donations.donation_amount,0)) as amt from registrations
INNER JOIN `users`
ON registrations.user_id = users.user_id
AND registrations.event_id = :event_id
LEFT OUTER JOIN `donations`
ON registrations.reg_id = donations.reg_id
GROUP BY donations.reg_id
ORDER BY users.user_name ASC