compare two values in sql with eachother - mysql

I have a database of magento with double images, I want to delete those but first i got to detect them with a sql query.
I have tried this code
select t1.VALUE from catalog_product_entity_media_gallery t1
join catalog_product_entity_media_gallery t2 on (t1.value = t2.value)
this one:
select * from catalog_product_entity_media_gallery where value=value
and this one:
select
*
from
(
select
value
from
catalog_product_entity_media_gallery
group by
value
having count(*) > 1
) as t
inner join catalog_product_entity_media_gallery on (
catalog_product_entity_media_gallery.value = t.value
)
the first gives an error and the second- and third one gives back every product.

Give this one a try:
select
*
from (
select
entity_id,attribute_id,value,
MIN(value_id) value_id
from catalog_product_entity_media_gallery
group by
entity_id,attribute_id,value
having COUNT(*) > 1
) A1
inner join catalog_product_entity_media_gallery A2 on
A1.entity_id = A2.entity_id and
A1.attribute_id = A2.attribute_id and
A1.value = A2.value and
A1.value_id = A2.value_id

You can just get the min id by value, then except the other records:
select
*
from catalog_product_entity_media_gallery t1
where exists
( select * from
(select value, min(value_id) as min_value_id
from catalog_product_entity_media_gallery
group by value
) as t2
where t1.value=t2.value and t1.value_id=t2.min_value_id
)
If you want delete the duplicated rows, change exists to not exists.
delete
from catalog_product_entity_media_gallery t1
where not exists
( select * from
(select value, min(value_id) as min_value_id
from catalog_product_entity_media_gallery
group by value
) as t2
where t1.value=t2.value and t1.value_id=t2.min_value_id
)

Related

Wrong count result in mysql when joining two tables

I am trying to join two tables and get the count and grouped by specific field. However, it outputs same count values even if the other table consist only two rows. How should I fix this?
Here's my code:
SELECT tbl1.preferredDay, COUNT(tbl1.preferredDay) as count_1, COUNT(tbl2.preferredDay) as count_2
FROM tblschedule as tbl1
LEFT JOIN tblappointments as tbl2 ON (tbl1.preferredDay = tbl2.preferredDay)
WHERE tbl1.preferredDay = tbl2.preferredDay
GROUP BY preferredDay;
Here is the output but it should be [15, 0][3, 3]
Your query is based on left join it will return the same count().
This is a working query for Mysql 8:
with tbl1 as (
SELECT preferredDay, count(1) as count_1
FROM tblschedule
GROUP BY preferredDay
),
tbl2 as (
SELECT preferredDay, count(1) as count_2
FROM tblappointments
GROUP BY preferredDay
)
select t1.preferredDay, t1.count_1, t2.count_2
from tbl1 t1
inner join tbl2 t2 on t1.preferredDay = t2.preferredDay
There are two WITHs to get separately the count and then an INNER JOIN to join those results
For Mysql 5.7 and lower :
select t1.preferredDay, t1.count_1, t2.count_2
from (
SELECT preferredDay, count(1) as count_1
FROM tblschedule
GROUP BY preferredDay
) as t1
inner join (
SELECT preferredDay, count(1) as count_2
FROM tblappointments
GROUP BY preferredDay
) as t2 on t1.preferredDay = t2.preferredDay

MySQL problem joining 2 tables with UNION

I'm doing UNION in MySQL that I'm unable to troubleshoot for a while.
Error says that
syntax is incorrect around t1.*
Those 2 SELECTs work ok separately, checked. But UNION fails. I'm not custom to MySQL syntax, maybe something is wrong with that.
SELECT (
t1.*,
a.region_count
FROM
(
SELECT
data_region,
COUNT(*) AS region_count
FROM
t2
GROUP BY
data_region
) AS a
LEFT OUTER JOIN
t1
ON
t1.values_att0 = a.data_region
WHERE
t1.name_0 = 'region'
) AS b
UNION
SELECT (
t1.*,
c.age_gen_count
FROM
(
SELECT
data_dage,
data_gen,
COUNT(*) AS age_gen_count
FROM
t2
GROUP BY
data_dage,
data_gen
) AS c
LEFT JOIN
t1
ON
t1.values_att0 = c.data_dage AND
t1.id_question_1 = c.data_gen
WHERE
t1.name_0 = 'age' AND
t1.q_name_1 = 'gen'
)
You are using parenthesis around your SELECT field, this is your syntax error origin (the UNION is not the cause). Just remove them:
SELECT
t1.*,
a.region_count
FROM
(
SELECT
data_region,
COUNT(*) AS region_count
FROM t2
GROUP BY data_region
) AS a
LEFT OUTER JOIN t1
ON t1.values_att0 = a.data_region
WHERE t1.name_0 = 'region'
UNION ALL
SELECT
t1.*,
c.age_gen_count
FROM
(
SELECT
data_dage,
data_gen,
COUNT(*) AS age_gen_count
FROM t2
GROUP BY data_dage, data_gen
) AS c
LEFT JOIN t1
ON t1.values_att0 = c.data_dage
AND t1.id_question_1 = c.data_gen
WHERE t1.name_0 = 'age'
AND t1.q_name_1 = 'gen'

This simple MySQL join will not work for me

Each individual query (t1 and t2) works fine by itself, however a simple join is seemingly not allowed.
I recreated the code using tables x1 and x2 and it was fine, however copy pasting t1 and t2 over the top gets me an error again.
It must be something to do with the variables?
problematic attempt:
select *
from
(
set #rownumber1 = 0;
select (#rownumber1:= #rownumber1 + 1) as num,
id,
updated_at as date,
risk_factor
from (select * from user.users_audit order by id) orig
order by id
) t1
left join
(
set #rownumber2 = 0;
select (#rownumber2:= #rownumber2 + 1) as num,
id,
updated_at as date,
risk_factor
from (select * from user.users_audit order by id) orig
order by id
) t2 on t1.id = t2.id
working attempt - but with tables I dont care about:
select *
from
(
select *
from sport_type_sources
) x1
inner join
(
select *
from sport_type_sources
) x2 on x1.id = x2.id
I would simply like to join the two tables.

How to remove duplicates from table using join in mysql

select *
from
(
SELECT id, imei1, status
FROM `owarranty_imei` mto
WHERE EXISTS
(
SELECT 1
FROM `owarranty_imei` mti
WHERE mto.imei1=mti.imei1
LIMIT 1, 1
)
) t1
left join `owarranty_warranty_activations` as t2 on t1.id=t2.imei_id
where t2.id is null
limit 100
this is my query. In owarranty_imei has more than 100000 records. i want to get duplicates from imei table which owarranty_imei not in owarranty_warranty_activation table. This query work for few records but when i run it for more than 1000000 records its not working
SELECT
mto.id,
mto.imei1,
mto.status
FROM
`owarranty_imei` mto
INNER JOIN
`owarranty_imei` mti ON mto.imei1=mti.imei1
LEFT JOIN
`owarranty_warranty_activations` as t2 ON mto.id=t2.imei_id
GROUP BY mto.id
HAVING COUNT(t2.id)=0

sql query question

I have tables
table 1
id text
1 A
1 B
2 C
table 2
id text
1 x
1 f
2 y
2 z
I want to join them this way
1 A x
1 B f
2 C y
2 z
In other words i want to see all texts from table1 and table2 grouped by id, with no repeats.
Any ideas?
Update: as they say in comments, the logic is not clear, I'll try to explain.
I have current values in table_1 and deleted values in table_2.
Customer wants to see current values and deleted values in one table grouped by some id.
Simple solution to get something close to what you're looking for
SELECT t1.id, t1.text, t2.text
FROM tbl_1 t1
INNER JOIN tbl_2 t2
ON t1.id = t2.id
this will create output
1 A x
1 B x
2 C y
2 C z
Only different is now that the duplicated texts x and C should somehow removed.
Update
precondition: duplicates per id are either in tbl_1 or tbl_2 not both !
Joining a grouped select in addition to above simple solution will allow to create kind of "CASE-Filters" to get your desired output.
SELECT
t1.id,
CASE
WHEN t2.text = txt_i2 THEN t1.text
END AS txt_t1,
CASE
WHEN t1.text = txt_i1 THEN t2.text
END AS txt_t2
FROM (
SELECT
i1.id,
i1.text AS txt_i1,
i2.text AS txt_i2
FROM tbl_1 i1
INNER JOIN tbl_2 i2
ON i1.id = i2.id
GROUP BY id
) i
INNER JOIN tbl_1 t1
ON i.id = t1.id
INNER JOIN tbl_2 t2
ON t1.id = t2.id
You should create a view of the tbl_1-tbl_2-join to get more readable SQL:
CREATE OR REPLACE VIEW V_tbl_1_2 AS (
SELECT
t1.id,
t1.text AS txt_1,
t2.text AS txt_2
FROM tbl_1 t1
INNER JOIN tbl_2 t2
ON t1.id = t2.id
)
;
SELECT
t.id,
CASE
WHEN t.txt_2 = i.txt_2 THEN t.txt_1
END AS txt_t1,
CASE
WHEN t.txt_1 = i.txt_1 THEN t.txt_2
END AS txt_t2
FROM V_tbl_1_2 t
INNER JOIN (
SELECT *
FROM V_tbl_1_2
GROUP BY id
) i ON t.id = i.id
;
USE MYSQL VIEW OR JOIN
This works if you can have no more than two items per id in either table and if neither one has complete duplicates. (And I must also add that this can only work if MySQL is able to swallow this monster and not choke with it.)
SELECT
COALESCE (t1.id, t2.id) AS id,
t1.text AS text1,
t2.text AS text2
FROM (
SELECT
t.id,
t.text,
CASE t.text WHEN m.text THEN 1 ELSE 2 END AS rowid
FROM table_1 t
INNER JOIN (
SELECT id, MIN(text) AS text
FROM table_1
GROUP BY id
) m ON t.id = m.id
) t1
FULL JOIN (
SELECT
t.id,
t.text,
CASE t.text WHEN m.text THEN 1 ELSE 2 END AS rowid
FROM table_2 t
INNER JOIN (
SELECT id, MIN(text) AS text
FROM table_2
GROUP BY id
) m ON t.id = m.id
) t2
ON t1.id = t2.id AND t1.rowid = t2.rowid
ORDER BY COALESCE (t1.id, t2.id), COALESCE (t1.rowid, t2.rowid)