Converting complex MySQL query to UPDATE statement - mysql

Question

I have a quite complex Mysql query:
SELECT
metabase_field.description, rows_to_copy.description,
metabase_field.display_name, rows_to_copy.display_name
FROM
metabase_field LEFT JOIN (select id as table_id, name as t_name from metabase_table) metabase_field_table ON metabase_field.table_id=metabase_field_table.table_id,
(
SELECT metabase_field.name as name, metabase_field_table.t_name as t_name, metabase_field.display_name as display_name, metabase_field.description as description, metabase_field.special_type as type
FROM metabase_field
LEFT JOIN (select id as table_id, name as t_name, db_id, active, visibility_type from metabase_table) metabase_field_table ON metabase_field.table_id = metabase_field_table.table_id
LEFT JOIN metabase_database metabase_field_table_database ON metabase_field_table.db_id = metabase_field_table_database.id
where metabase_field_table.active=1 and metabase_field_table.visibility_type is null and metabase_field_table_database.name = 'Prod'
) as rows_to_copy
WHERE
metabase_field_table.table_id IN (
SELECT distinct(metabase_table.id) as ids
from metabase_table
LEFT JOIN metabase_database metabase_table_database ON metabase_table.db_id = metabase_table_database.id
where metabase_table_database.name = 'Dev' and metabase_table.active=1 and metabase_table.visibility_type is null
)
and metabase_field_table.t_name = rows_to_copy.t_name
and metabase_field.name = rows_to_copy.name
This returns a table looking a bit like this:
+-------------+-------------+--------------+--------------+
| description | description | display_name | display_name |
+-------------+-------------+--------------+--------------+
| NULL | to copy | Application | Application |
Without going to deep into details, I just wanted to copty results from rows_to_copy to metabase_field fields, which means to set:
metabase_field.description = rows_to_copy.description,
metabase_field.display_name = rows_to_copy.display_name
I tried to just change SELECT to UPDATE:
UPDATE
metabase_field LEFT JOIN (select id as table_id, name as t_name from metabase_table) metabase_field_table ON metabase_field.table_id=metabase_field_table.table_id,
(
SELECT metabase_field.name as name, metabase_field_table.t_name as t_name, metabase_field.display_name as display_name, metabase_field.description as description, metabase_field.special_type as type
FROM metabase_field
LEFT JOIN (select id as table_id, name as t_name, db_id, active, visibility_type from metabase_table) metabase_field_table ON metabase_field.table_id = metabase_field_table.table_id
LEFT JOIN metabase_database metabase_field_table_database ON metabase_field_table.db_id = metabase_field_table_database.id
where metabase_field_table.active=1 and metabase_field_table.visibility_type is null and metabase_field_table_database.name = 'Prod'
) as rows_to_copy
SET
metabase_field.description = rows_to_copy.description,
metabase_field.display_name = rows_to_copy.display_name
WHERE
metabase_field_table.table_id IN (
SELECT distinct(metabase_table.id) as ids
from metabase_table
LEFT JOIN metabase_database metabase_table_database ON metabase_table.db_id = metabase_table_database.id
where metabase_table_database.name = 'Dev' and metabase_table.active=1 and metabase_table.visibility_type is null
)
and metabase_field_table.t_name = rows_to_copy.t_name
and metabase_field.name = rows_to_copy.name
;
But this query doesn't seem to change anything - the results stay the way they were. Is there any simple way to make it work?

Answer 1

After some formating I realize if almost imposible keep track of table names. use shorter and different alias to avoid bugs. I try to improve the rest of the code but too much work
I think the problem is the update. Update table should have the alias MF, and you SET MF.<field>
If that doesnt work, remove the WHERE and see if you UPDATE something. Of course only if you can do testing on those tables.
If that doesnt work, start with a single table and add one join at each time.
UPDATE metabase_field MF -- main alias for table to update.
LEFT JOIN (SELECT id as table_id, name as t_name
FROM metabase_table) MT1
ON MF.table_id = MT1.table_id
CROSS JOIN ( SELECT MF1.name as name,
MT2.t_name as t_name,
MF1.display_name as display_name,
MF1.description as description,
MF1.special_type as type
FROM metabase_field MF1
LEFT JOIN (SELECT id as table_id,
name as t_name,
db_id, active,
visibility_type
from metabase_table) MT2
ON MF1.table_id = MT2.table_id
LEFT JOIN metabase_database MD
ON MT2.db_id = MD.id
WHERE MT2.active = 1
and MT2.visibility_type is null
and MD.name = 'Prod'
) as rows_to_copy
SET
MF.description = rows_to_copy.description,
MF.display_name = rows_to_copy.display_name
WHERE
metabase_field_table.table_id IN (
SELECT distinct(metabase_table.id) as ids
from metabase_table
LEFT JOIN metabase_database MB
ON MT2.db_id = MB.id
WHERE MB.name = 'Dev'
and MT2.active=1
and MT2.visibility_type is null
)
and metabase_field_table.t_name = rows_to_copy.t_name
and metabase_field.name = rows_to_copy.name
;

Answer 2

Update metabase_field set metabase_field.description=
rows_to_copy.description, metabase_field.display_name=
rows_to_copy.display_name LEFT JOIN (select id as table_id, name as
t_name from metabase_table) metabase_field_table ON
metabase_field.table_id=metabase_field_table.table_id, ( SELECT
metabase_field.name as name, metabase_field_table.t_name as t_name,
metabase_field.display_name as display_name,metabase_field.description as description, metabase_field.special_type
as type FROM metabase_field LEFT JOIN (select id as table_id, name as
t_name, db_id, active, visibility_type from metabase_table)
metabase_field_table ON metabase_field.table_id =
metabase_field_table.table_id LEFT JOIN metabase_database
metabase_field_table_database ON metabase_field_table.db_id =
metabase_field_table_database.id where metabase_field_table.active=1
and metabase_field_table.visibility_type is null and
metabase_field_table_database.name = 'Prod' ) as rows_to_copy WHERE
metabase_field_table.table_id IN ( SELECT distinct(metabase_table.id)
as ids from metabase_table LEFT JOIN metabase_database
metabase_table_database ON metabase_table.db_id =
metabase_table_database.id where metabase_table_database.name = 'Dev'
and metabase_table.active=1 and metabase_table.visibility_type is null
) and metabase_field_table.t_name = rows_to_copy.t_name and
metabase_field.name = rows_to_copy.name
Try this