I have two table user_table and subscription_table
user_table
| user_id(int)| email(varchar) | phone(int)|
------------------------------------------------
| 1 | abc#gmail.com | 9910256256 |
| 2 | def#gmail.com | 8856956325 |
| 3 | ghi#gmail.com | 8745692455 |
| 4 | jkl#gmail.com | 7852369526 |
subscription_table
| email(varchar) | type(varchar)| is_subscribed(boolean)
------------------------------------------------------------------
| abc#gmail.com | news | true
| abc#gmail.com | video | false
| def#gmail.com | news | true
| def#gmail.com | video | true
I have user_id and want to update is_subscription. Best wayto update is_subscription.
I have tried to do it with multiple query but i think that is not good.
Is this what you want?
update subscription_table s
set is_subscription = ?
from user_table u
where u.email = s.email and u.user_id= ?;
Note: If you have a user_id, then you should be using that for foreign key relationships. I don't understand why email would be used for this purpose.
Related
I have three different tables here:
df_umts_relation table:
|---------------------|------------------|---------------------|------------------|------------------|
| cell_name | n_cell_name | technology | source_ops_num | target_ops_num |
|---------------------|------------------|---------------------|------------------|------------------|
| 121 | 221 | UMTS | 1 | | |
|---------------------|------------------|---------------------|------------------|------------------|
| 122 | 222 | GSM | 2 | | |
|---------------------|------------------|---------------------|------------------|------------------|
| 123 | 223 | UMTS | 3 | | |
|---------------------|------------------|---------------------|------------------|------------------|
| 124 | 224 | GSM | 4 | | |
|---------------------|------------------|---------------------|------------------|------------------|
| 125 | 225 | GSM | 5 | | |
|---------------------|------------------|---------------------|------------------|------------------|
| 126 | 226 | UMTS | 6 | | |
|---------------------|------------------|---------------------|------------------|------------------|
| 127 | 227 | UMTS | 7 | | |
|---------------------|------------------|---------------------|------------------|------------------|
So now I want to update target_ops_num from the two below tables
df_umts_carrier table as this table contains those thow columns I want to work on them and contains some integer values also:
|---------------------|------------------|
| opsnum_umts | cell_name_umts |
|---------------------|------------------|
as I have another table called df_gsm_carrier:
|---------------------|------------------|
| opsnum_gsm | cellname |
|---------------------|------------------|
So All I need I want to update [MyNewDatabase].[dbo].[df_umts_relation].[target_ops_num] CASE WHEN technologyis UMTS then update from table df_umts_carrier ELSE technology is GSM then update from df_gsm_carrier on n_cell_name = cell_name_umts and on n_cell_name = cellname
So I tried to create a query as the below one works with one condition only and it's update the the rows which is UMTS only:
UPDATE [MyNewDatabase].[dbo].[df_umts_relation]
SET [MyNewDatabase].[dbo].[df_umts_relation].[target_ops_num] = [MyNewDatabase].[dbo].[df_umts_carrier].[opsnum_umts]
FROM [MyNewDatabase].[dbo].[df_umts_relation]
INNER JOIN [MyNewDatabase].[dbo].[df_umts_carrier]
ON [n_cell_name] = [cell_name_umts]
and works fine but doesn't update the rows which contains GSM...
On other way I tried to create a query to handle this but it didn't update the GSM part and take a long of time:
UPDATE [MyNewDatabase].[dbo].[df_umts_relation]
SET [MyNewDatabase].[dbo].[df_umts_relation].[target_ops_num] = (CASE WHEN [MyNewDatabase].[dbo].[df_umts_relation].[technology] = 'UMTS'
THEN [MyNewDatabase].[dbo].[df_umts_carrier].[opsnum_umts] ELSE [MyNewDatabase].[dbo].[df_gsm_carrier].[opsnum_gsm] END)
FROM [MyNewDatabase].[dbo].[df_umts_relation]
LEFT JOIN [MyNewDatabase].[dbo].[df_umts_carrier]
ON [n_cell_name] = [cell_name_umts]
LEFT JOIN [MyNewDatabase].[dbo].[df_gsm_carrier]
ON [n_cell_name] = [cell_name]
So any one have any idea how to solve this?
Please check if this will help.
update df_umts_relation
set target_ops_num = ( select case when dur.technology = 'UMTS' then du.cell_name_umts
when dur.technology = 'GSM' then dg.cellname
end
from df_umts_relation dur
left join df_umts_carrier du on dur.n_cell_name = du.opsnum_umts
left join df_gsm_carrier dg on dur.n_cell_name = dg.opsnum_umts
where dur.id= df_umts_relation.id)
Here is a demo
I apologise in advance because I have no idea how to structure this question.
I have the following tables:
Sessions:
+----------+---------+
| login | host |
+----------+---------+
| breilly | node001 |
+----------+---------+
| pparker | node003 |
+----------+---------+
| jjameson | node004 |
+----------+---------+
| jjameson | node012 |
+----------+---------+
Userlist:
+----------+----------------+------------------+
| login | primary_server | secondary_server |
+----------+----------------+------------------+
| breilly | node001 | node010 |
+----------+----------------+------------------+
| pparker | node002 | node003 |
+----------+----------------+------------------+
| jjameson | node003 | node004 |
+----------+----------------+------------------+
What kind of SQL query should I perform so I can get a table like this?:
+----------+---------+------------+
| login | Host | Server |
+----------+---------+------------+
| jjameson | node004 | Secondary |
+----------+---------+------------+
| jjameson | node012 | Wrong Node |
+----------+---------+------------+
| pparker | node003 | Secondary |
+----------+---------+------------+
| breilly | node001 | Primary |
+----------+---------+------------+
Currently I'm just using Go with a bunch of structs / hashmaps to generate this.
I am planning to migrate the users / sessions to an in memory sqlite Database, but I can't seem to wrap my head around a query to get this sort of table.
The Server column is based on whether the user is logged on his primary / secondary or wrong machine.
I've put this in SQL Fiddle as well
Use case logic:
select s.*,
(case when s.host = ul.primary_server then 'primary'
when s.host = ul.secondary_server then 'secondary'
else 'wrong node'
end) as server
from sessions s left join
userlist ul
on s.login = ul.login;
Basically, I have 3 tables, titles, providers, and provider_titles.
Let's say they look like this:
| title_id | title_name |
|------------|----------------|
| 1 | San Andres |
| 2 |Human Centipede |
| 3 | Zoolander 2 |
| 4 | Hot Pursuit |
| provider_id| provider_name |
|------------|----------------|
| 1 | Hulu |
| 2 | Netflix |
| 3 | Amazon_Prime |
| 4 | HBO_GO |
| provider_id| title_id |
|------------|----------------|
| 1 | 1 |
| 1 | 2 |
| 2 | 1 |
| 3 | 1 |
| 3 | 3 |
| 4 | 4 |
So, clearly there are titles with multiple providers, yeah? Typical many-to-many so far.
So what I'm doing to query it is with a JOIN like the following:
SELECT * FROM provider_title JOIN provider ON provider_title.provider_id = provider.provider_id JOIN title ON title.title_id = provider_title.title_id WHERE provider.name IN ('Netflix', 'HBO_GO', 'Hulu', 'Amazon_Prime')
Ok, now to the actual issue. I don't want repeated title names back, but I do want all of the providers associated with the title. Let me explain with another table. Here is what I am getting back with the current query, as is:
| provider_id| provider_name | title_id | title_name |
|------------|---------------|----------|---------------|
| 1 | Hulu | 1|San Andreas |
| 1 | Hulu | 2|Human Centipede|
| 2 | Netflix | 1|San Andreas |
| 3 | Amazon_Prime | 1|San Andreas |
| 3 | Amazon_prime | 3|Zoolander 2 |
| 4 | HBO_GO | 4|Hot Pursuit |
But what I really want would be something more like
| provider_id| provider_name |title_id| title_name|
|------------|-----------------------------|--------|-----------|
| [1, 2, 3] |[Hulu, Netflix, Amazon_Prime]| 1|San Andreas|
Meaning I only want distinct titles back, but I still want each title's associated providers. Is this only possible to do post-sql query with logic iterating through the returned rows?
Depending on your database engine, there may be an aggregation function to help achieve this.
For example, this SQLfiddle demonstrates the postgres array_agg function:
SELECT t.title_id,
t.title_name,
array_agg( p.provider_id ),
array_agg( p.provider_name )
FROM provider_title as pt
JOIN
provider as p
ON pt.provider_id = p.provider_id
JOIN title as t
ON t.title_id = pt.title_id
GROUP BY t.title_id,
t.title_name
Other database engines have equivalents. For example:
mySQL has group_concat
Oracle has listagg
sqlite has group_concat (as well!)
If your database isn't covered by the above, you can google '[Your database engine] aggregate comma delimited string'
I have a table in Access named Spells which holds patient spells (where a patient has a spell within a hospital). It's structure is as below:
| ID | SpellID | MultipleSpell | FirstSpell | LastSpell |
|----|---------|---------------|------------|-----------|
| 1 | 1 | False | | |
| 2 | 2 | True | | |
| 3 | 2 | True | | |
| 4 | 3 | False | | |
| 5 | 4 | False | | |
| 6 | 5 | True | | |
| 7 | 5 | True | | |
| 8 | 5 | True | | |
The MultipleSpell column indicates that there are multiple occurrences of the spell within the table.
I'd like to run query which would update the FirstSpell column to True for records with the IDs of 1,2,4,5,6. So basically, where a Spell is the first one in the table, it should be marked, in the FirstSpell column.
I would also then like to update the LastSpell column to True for records with the IDs of 1,3,4,5,8.
The reasoning for this (if you're interested) is that the table links to a separate table containing the name of wards. It would be useful to link to this other table and indicate whether the ward is the admitting ward (FirstSpell) or the discharging ward (LastSpell)
You can update the first using:
update spells
set firstspell = 1
where id = (select min(id)
from spells as s2
where spells.spellid = s2.spellid
);
Similar logic (using max()) can be used for the last spell.
I have these two tables that i need to join
fields_data fields
+------------+-----------+------+ +------+-------------+----------+
| relationid | fieldname | data | | name | displayname | position |
+------------+-----------+------+ +------+-------------+----------+
| 2 | ftp | test | | user | Username | top |
| 2 | other | 1234 | | pass | Password | top |
+------------+-----------+------+ | ftp | FTP | top |
| log | Log | top |
| txt | Text | mid |
+------+-------------+----------+
I want to get all the rows from the "fields" table if they have the position "top" AND if a row has a match on name = fieldname from fields_data it should also show the data. This is my join
SELECT
fd.`data`,
fd.`relationid`,
fd.`fieldname`,
f.`name`,
f.`displayname`
FROM `fields` AS f
LEFT OUTER JOIN `fields_data` AS fd
ON fd.`fieldname` = f.`name`
WHERE f.`position`='top' AND (fd.`relationid`='3' OR fd.`relationid` IS NULL)
My problem is that the above query only gives me this result:
+------+------------+-----------+------+-------------+
| data | relationid | fieldname | name | displayname |
+------+------------+-----------+------+-------------+
| NULL | NULL | NULL | user | Username |
| NULL | NULL | NULL | pass | Password |
| NULL | NULL | NULL | log | Log |
+------+------------+-----------+------+-------------+
The field called "ftp" is missing due to it having a relation to "2".. However i still want to display it as result but like the others with NULL in it. And if the SQL query had "fd.relationid='2'" instead of 3 it would give same result, but with the row containing ftp in name, holding data in the three fields.
I hope you get what i mean.. My english is not the best.. Heres the result i want:
with above query containing fd.`relationid`='3'
+------+------------+-----------+------+-------------+
| data | relationid | fieldname | name | displayname |
+------+------------+-----------+------+-------------+
| NULL | NULL | NULL | user | Username |
| NULL | NULL | NULL | pass | Password |
| NULL | NULL | NULL | ftp | FTP |
| NULL | NULL | NULL | log | Log |
+------+------------+-----------+------+-------------+
with above query containing fd.`relationid`='2'
+------+------------+-----------+------+-------------+
| data | relationid | fieldname | name | displayname |
+------+------------+-----------+------+-------------+
| NULL | NULL | NULL | user | Username |
| NULL | NULL | NULL | pass | Password |
| test | 2 | ftp | ftp | FTP |
| NULL | NULL | NULL | log | Log |
+------+------------+-----------+------+-------------+
You want to move the condition to the on clause:
SELECT fd.`data`, fd.`relationid`, fd.`fieldname`, f.`name`, f.`displayname`
FROM `fields` f LEFT OUTER JOIN
`fields_data` fd
ON fd.`fieldname` = f.`name` AND fd.`relationid` = '3'
WHERE f.`position`='top' ;
It is interesting that the semantics of your query and this query are different -- and you found the exact situation: when there is a match on another value, the where clause form filters out the row. This will still keep everything.
As a note, the following also does what you want:
SELECT fd.`data`, fd.`relationid`, fd.`fieldname`, f.`name`, f.`displayname`
FROM `fields` f LEFT OUTER JOIN
(SELECT fd.*
FROM `fields_data` fd
WHERE fd.`relationid` = '3'
) fd
ON fd.`fieldname` = f.`name`
WHERE f.`position` = 'top' ;
I wouldn't recommend writing the query this way, particularly in MySQL (because the subquery is materialized). However, understanding why your version is different from these versions (and why these are the same) is a big step forward in mastering outer joins.