I am trying to join a few tables in swift using the SQLite.swift library and I am having a few problems. The below code shows the issue:
I first join the tables:
let ext_tasks = tasks.join(tasktypes, on: tasktypes[tty_id] == tasks[task_type])
.join(preUsers, on: preUsers[Worker_ID] == task_ownerID)
.order(task_dueDate)
.filter(task_ownerID == iUserID)
At this point I have the tables joined and all the fields from tasks, task types and preUsers are there properly.
Following I run the second join statement:
let ext_equipment = equipment.join(equipment_type, on: equipment_type[eqt_id] == equipment[equ_type])
.join(facilities, on: facilities[fac_id] == equipment[equ_facid])
.join(eqowners, on: eqowners[Worker_ID] == equipment[equ_owner])
.order(equ_make)
.filter(equ_status >= 0)
Again, after running this statement I can access all the fields from the equipment, equipment_type, facilities and eqowners tables, up to here everything is working as expected...
However then I try to join the two above results using:
let comp_tasks = ext_tasks.join(ext_equipment, on: ext_equipment[equ_id] == ext_tasks[task_eqID])
.order(task_dueDate)
Here is where I run into a problem, it seems like the tables coming from the ext_tasks query are there but only the equipment table from the ext_equipment query is available.
Further when I try to access the "facilities"."facility_name" field, I get the following message saying that the field does not exist:
fatal error: no such column '"Facilities"."Facility_Name"' in columns:
["Equipment"."EquipmentType_ID", "Equipment"."Equipment_ID", "Equipment"."Equipment_Owner_ID", "Equipment"."Facility_ID", "Equipment"."Status", "PreUsers"."Client_ID", "PreUsers"."Date_LastLogin", "PreUsers"."First_Name", "TaskTypes"."TaskType_ID", "TaskTypes"."Type", "Tasks"."Equipment_ID", "Tasks"."Owner_ID", "Tasks"."Priority", "Tasks"."Time_Complete", "Tasks"."Time_Start"]:
(I removed some of the columns in there to shorten the answer, there are 53 fields in total shown) but as you can see only tables from the first join + the equipment table are shown, the joins from the second query (equipment_type, facilities and eqowners) are nowhere to be seen
I would appreciate if someone could let me know why this is happening, this has been killing my brain for hours and I just can't figure it out...
Thanks in advance!
Related
Can someone identify why this multi-table join is not accepted? When I bring in the third table, it then fails with invalid table alias. I am not seeing what is wrong:
This works (two table):
select
a.ri as `R_ID`
,oc3.name as `RET`
,a.rch as `RC`
from dev.sl a join dev.codes oc3
on (a.pk_business = oc3.pk_business
and a.pk_data_source = oc3.pk_data_source
and a.pk_frequency = oc3.pk_frequency
and oc3.pk_data_state = '123'
and oc3.code = a.ri and oc3.codeset = 'xyz')
Then add a third table and it fails:
(Three table):
select
a.ri as `R_ID`
,oc3.name as `RET`
,a.rch as `RC`
from dev.sl a join dev.codes oc3
on (a.pk_business = oc3.pk_business
and a.pk_data_source = oc3.pk_data_source
and a.pk_frequency = oc3.pk_frequency
and oc3.pk_data_state = '123'
and oc3.code = a.ri and oc3.codeset = 'xyz') join dev.items b
on (b.pk_business = a.pk_business
and b.pk_data_source = a.pk_data_source
and b.pk_frequency = a.pk_frequency
and b.pk_data_state = '123'
and a.ii = b.item_id
and a.cc = b.country_code)
SemanticException [Error 10009]: Line 1:2920 Invalid table alias 'a':
I have an update - it seems that this was caused by having one table created as an updatable table (TBLPROPERTIES ('transactional'='true')), and one without, and with my session settings of:
SET hive.txn.manager=org.apache.hadoop.hive.ql.lockmgr.DbTxnManager;
SET hive.support.concurrency=true;
SET hive.enforce.bucketing=true;
SET hive.exec.dynamic.partition.mode=nonstrict;
This caused the problem. On another session without the settings AND repointing to an identical table "a" created as a non-ACID type table, the multi-table join worked fine. I don't know enough about HIVE to know why - I suspect that a transactional and non-transactional table cannot be joined in the same "transaction" (select statement).
One more update - It may not be due to the transactional table. With additional testing, I now also see it happens with non-transactional tables as well. It seems that the three table join works when I execute it from a putty session directly on the server, but when I use SQL Developer, it will produce the aforementioned error. It appears to be an issue with SQL Developer, but why still is unknown.
I have a many-to-many relationship so I have three tables (administrators, offices and the intermediate table):
I need to do a very simple innerjoin of the three tables to show lastnames and their offices with Active Record. I tried but I couldn't.
This is what I tried:
$admins = Admins::find()
->joinWith(Oficinas::tableName())
->all();
echo '<pre>';
print_r($admins);
echo '</pre>';
die();
Also I would like to know how to show the SQL query so it can help me to find a solution.
You need to specify the relation name for joinWith() rather than table names. Since there isn't any info on the relation names I will use simple innerJoin using table names as per your requirements to display the last name and the office name for the admins.
Admins::find()
->alias('a')
->select('a.lastnameadm, o.nombreofi')
->innerJoin('admin_oficinas ao','ao.idadm = a.idadm')
->innerJoin('oficinas o','o.idofi = ao.idofi')
->all();
Try this:
TABLE_NAME_1::find()
->join('inner join',
'table_name_2',
'table_name_2.column = table_name_1.column'
);
->join('inner join',
'table_name_3',
'table_name_3.column = table_name_2.column'
)->all();
but if you can also use Via like the following example:
public function getClassschedule()
{
return $this->hasOne(TABLE_NAME_2::className(), ['table_name_1.column' => 'table_name_2.column'])
->via('tableName3');
}
when excuded, the results should be obtained like the previous example. so there's no need to repeated relations. full documentation can be seen here :
https://www.yiiframework.com/doc/guide/2.0/en/db-active-record
We recently upgraded to Rails 4.2 from Rails 4.1 and are seeing problems with using Arel + Activerecord because we're getting this type of error:
ActiveRecord::StatementInvalid: PG::ProtocolViolation: ERROR: bind message supplies 0 parameters, but prepared statement "" requires 8
Here's the code that is breaking:
customers = Customer.arel_table
ne_subquery = ImportLog.where(
importable_type: Customer.to_s,
importable_id: customers['id'],
remote_type: remote_type.to_s.singularize,
destination: 'hello'
).exists.not
first = Customer.where(ne_subquery).where(company_id: #company.id)
second = Customer.joins(:import_logs).merge(
ImportLog.where(
importable_type: Customer.to_s,
importable_id: customers['id'],
remote_type: remote_type.to_s.singularize,
status: 'pending',
destination: 'hello',
remote_id: nil
)
).where(company_id: #company.id)
Customer.from(
customers.create_table_alias(
first.union(second),
Customer.table_name
)
)
We figured out how to solve the first part of the query (running into the same rails bug of not having bindings) by moving the exists.not to be within Customer.where like so:
ne_subquery = ImportLog.where(
importable_type: Customer.to_s,
importable_id: customers['id'],
destination: 'hello'
)
first = Customer.where("NOT (EXISTS (#{ne_subquery.to_sql}))").where(company_id: #company.id)
This seemed to work but we ran into the same issue with this line of code:
first.union(second)
whenever we run this part of the query, the bindings get lost. first and second are both active record objects but as soon as we "union" them, they lose the bindings are become arel objects.
We tried cycling through the query and manually replacing the bindings but couldn't seem to get it working properly. What should we do instead?
EDIT:
We also tried extracting the bind values from first and second, and then manually replacing them in the arel object like so:
union.grep(Arel::Nodes::BindParam).each_with_index do |bp, i|
bv = bind_values[i]
bp.replace(Customer.connection.substitute_at(bv, i))
end
However, it fails because:
NoMethodError: undefined method `replace' for #<Arel::Nodes::BindParam:0x007f8aba6cc248>
This was a solution suggested in the rails github repo.
I know this question is a bit old, but the error sounded familiar. I had some notes and our solution in a repository, so I thought I'd share.
The error we were receiving was:
PG::ProtocolViolation: ERROR: bind message supplies 0 parameters, but
prepared statement "" requires 1
So as you can see, our situation is a bit different. We didn't have 8 bind values. However, our single bind value was still being clobbered. I changed the naming of things to keep it general.
first_level = Blog.all_comments
second_level = Comment.where(comment_id: first_level.select(:id))
third_level = Comment.where(comment_id: second_level.select(:id))
Blog.all_comments is where we have the single bind value. That's the piece we're losing.
union = first_level.union second_level
union2 = Comment.from(
Comment.arel_table.create_table_alias union, :comments
).union third_level
relation = Comment.from(Comment.arel_table.create_table_alias union2, :comments)
We created a union much like you except that we needed to union three different queries.
To get the lost bind values at this point, we did a simple assignment. In the end, this is a little simpler of a case than yours. However, it may be helpful.
relation.bind_values = first_level.bind_values
relation
By the way, here's the GitHub issue we found while working on this. It doesn't appear to have any updates since this question was posted though.
I have this, but it loads each and every ebay row individually, generating thousands of SQL statements:
$products = \app\models\Product::find()
->joinWith('ebay', false, 'inner join')
->indexBy(function($row){return $row->ebay->epid;})
->all();
I tried this, but it gave an error: 'Getting unknown property: app\models\Product::ebay.epid'
$products = \app\models\Product::find()
->joinWith('ebay', false, 'inner join')
->indexBy('ebay.epid')
->all();
Setting eager loading = true doesn't help either. It still loads each row individually then loads them again at the end.
How can I efficiently join a table in Yii and index by a value in the joined table?
You won't be able to do it with indexBy. However, ArrayHelper::index can index an array on a related model field. So here's how it can be done:
$products = \app\models\Product::find()
->with('ebay')
->all();
ArrayHelper::index($products, 'ebay.epid');
The code will run two queries, one to get all products, one to get all related ebay products. Then the array will be indexed with no DB queries at all.
I ended up doing it manually for a subset of the ids and it only uses 2 queries. I'd still be interested in the indexBy though.
$products = Product::find()->joinWith('ebay', true, 'inner join')->where(['ebay.epid' => $productIds])->all();
$ebayProducts = array();
foreach ($products as $p) {
$ebayProducts[$p->ebay->epid] = $p;
}
If you want index by relation recods via joinWith() or with() results you can use following:
->with(['relationName' => function($q) {
$q->indexBy('field_name');
}])
With this code:
candidates = Challenge.joins(:projectmilestone).where("challenges.id in (?) and projectmilestones.user_id = ?", c.subtree_ids, assignee.id)
logger.debug "candidates: #{candidates.count}"
I get this into my logs:
SELECT COUNT(*) FROM "challenges" INNER JOIN "projectmilestones" ON "projectmilestones"."id" = "challenges"."projectmilestone_id" WHERE (challenges.id in (1122) and projectmilestones.user_id = 123)
Candidate projectmilestones: 0
When I run the query straight in the database, the result is 1
Why does Activerecord tells me that the result = 0?
Please note that when I remove "and projectmilestones.user_id" from the code, then it performs right.
This has been driving me crazy for a couple of hours...
Wrong SQL statement: challenges.id in (1122)
If c.subtree_ids returns array, then:
c.subtree_ids.join(", ")
I've got it: I changed the user_id before triggering the above query but I saved it afterwards...
This is why, when running the code, it was incorrect but when cross-checking, it was ok...
Nothing was wrong with rails, it was with wrong with me... Sorry and thanks for your help!