SQLAlchemy: Is there a way to append raw query to query object? - sqlalchemy

I'm trying to create a custom query with BigQuery in Google
I can do almost everything using SQLAlchemy filter function
query = TestModel.query.filter(TestModel.timestamp.__gt__(1010101010))
But I want to add custom filter on where clause like below
AND EXISTS (SELECT * FROM UNNEST(column_name) WHERE column_key LIKE '%tit%')
Is there a way to append filter using string like above?

Raw query
You can clearly do this like below:
text_clause = text("EXISTS (SELECT * FROM UNNEST(column_name) WHERE column_key LIKE '%tit%')")
ts = 1010101010
q = (
session.query(TestModel)
.filter(TestModel.timestamp > ts)
.filter(text_clause)
)
But it is going to be cleaner and more maintainable to avoid it if you can.
ORM Query
Below should give you an idea on how to implement it:
ts = 1010101010
subq = (
select(literal("*"))
.select_from(func.unnest(TestModel.column_name))
.filter(TestModel.column_key.contains("tit"))
).exists()
q = (
session.query(TestModel)
.filter(TestModel.timestamp > ts)
.filter(subq)
)

Related

Sql Alchemy filter / where clause joined by OR not AND

I want to select a bunch distinct records based off a composite key. In SQL I'd write something like this:
SELECT * FROM security WHERE (
exchange_code = 'exchange_code_1' AND code = 'code_1')
OR (exchange_code = 'exchange_code_2' AND code = 'code_2')
...
OR (exchange_code = 'exchange_code_N' AND code = 'code_N')
)
With SQLAlchemy I'd like to use the filter clause like:
query = sess.query(Security)
[query.filter(
and_(Security.exchange_code == security.exchange_code,
Security.code == security.code)
) for security in securities]
result = query.all()
The problem is filter and where join clauses with an AND not an OR... is there some way to use filter with OR?
Or is my only choice to generate a bunch of individual select's and UNION them? Something like:
first = exchanges.pop()
query = reduce(lambda query, exchange: query.union(exchange.pk_query),
first.pk_query())
query.all()
Use or_:
query = sess.query(Security).filter(
or_(*(and_(Security.exchange_code == security.exchange_code,
Security.code == security.code)
for security in securities)))
If your database supports it, you should use tuple_ instead.

SQL substring Issue ( Where substring(...) = (select....) )

I'm trying to search only the dirname from full path using this queries.
SELECT
`file_name` FROM `tbl_files` where SUBSTR(`file_path`,
LOCATE('/',`file_path`)+1,
(CHAR_LENGTH(`file_path`) - LOCATE('/',REVERSE(`file_path`)) - LOCATE('/',`file_path`))) =
(Select `source_path` from `tbl_transcode_folder` where `trancode_folder_id` = 1 )
But it return me nothing. When i replace (Select source_path from tbl_transcode_folder where trancode_folder_id = 1 ) into it's result mnt/hd/1 like the queries below , It's response want i to but i dont want to do in that way.
SELECT
`file_name` FROM `tbl_files` where SUBSTR(`file_path`,
LOCATE('/',`file_path`)+1,
(CHAR_LENGTH(`file_path`) - LOCATE('/',REVERSE(`file_path`)) - LOCATE('/',`file_path`))) = `mnt/hd/1`
Right now your sub-query returns a random row from the table you need to define a relation between the tbl_transcode_folder table, you need to define a relation between the outer query and the sub-query to make them correlated
SELECT `file_name`
FROM `tbl_files`
where SUBSTR(`file_path`, LOCATE('/',`file_path`)+1
,(CHAR_LENGTH(`file_path`) - LOCATE('/',REVERSE(`file_path`))
- LOCATE('/',`file_path`)))
=(Select `source_path`
from `tbl_transcode_folder`
where `trancode_folder_id` = 1
AND `tbl_files`.`CommonColumn` = `tbl_transcode_folder`.`CommonColumn`)

Laravel 4 - SQL query to Laravel Eloquent query

I'm working on a school project and I'm trying to get a query working.
SELECT *
FROM `ziekmeldingen` AS a
WHERE NOT EXISTS
(SELECT *
FROM `ziekmeldingen` AS b
WHERE `ziek` = 1
AND a.personell_id = b.personell_id)
Name of the model: ZiekmeldingenModel
I tried 2 things, both dont work ->
$medewerkers = ZiekmeldingenModel::whereNotExists(function($query)
{
$query->select()->from('ziekmeldingen AS b')->where('ziek', '=', '1')->where('ziekmeldingen.personell_id', '=', 'b.personell_id');
})->get();
return $medewerkers;
And
$medewerkers = ZiekmeldingenModel::raw('SELECT * FROM `ziekmeldingen` as a WHERE NOT EXISTS ( SELECT * FROM `ziekmeldingen` as b WHERE `ziek` = 1 AND a.personell_id = b.personell_id)')->get();
Both of them give back all the results from the table while it should only give back 1 result (I've tested the original query, it works).
EDIT: Forgot to mention I'm using relationships in the model. So the raw solution probably won't work anyway
Found the answer. Had to use a combo of both the things I tried.
$medewerkers = ZiekmeldingenModel::select()
->from(DB::raw('`ziekmeldingen` AS a'))
->whereNotExists(function($query){
$query->select()
->from(DB::raw('`ziekmeldingen` AS b'))
->whereRaw('`ziek` = 1 AND a.personell_id = b.personell_id');
})->get();
return $medewerkers;
Thanks for any help and effort.
Definitely no need for select(). Also no raw in from or whereRaw needed.
The only unusual thing here is raw piece in the where, since you don't want table.field to be bound and treated as string. Also, you can use whereRaw for the whole clause in case you have your tables prefixed, otherwise you would end up with something like DB_PREFIX_a.personell_id, so obviously wrong.
This is how you do it:
$medewerkers = ZiekmeldingenModel::from('ziekmeldingen AS a')
->whereNotExists(function ($q) {
$q->from('ziekmeldingen AS b')
->where('ziek', 1)
->where('a.personell_id', DB::raw('b.personell_id'))
// or:
// ->whereRaw('a.personell_id = b.personell_id');
})->get();
Use the take() method though if you're not ordering your results the record you get back could be any of the results.
$medewerkers = ZiekmeldingenModel::raw('SELECT * FROM `ziekmeldingen` as a WHERE NOT EXISTS ( SELECT * FROM `ziekmeldingen` as b WHERE `ziek` = 1 AND a.personell_id = b.personell_id)')->take(1)->get();

SQLAlchemy MySQL IF Statement

I'm in the middle of converting an old legacy PHP system to Flask + SQLAlchemy and was wondering how I would construct the following:
I have a model:
class Invoice(db.Model):
paidtodate = db.Column(DECIMAL(10,2))
fullinvoiceamount = db.Column(DECIMAL(10,2))
invoiceamount = db.Column(DECIMAL(10,2))
invoicetype = db.Column(db.String(10))
acis_cost = db.Column(DECIMAL(10,2))
The query I need to run is:
SELECT COUNT(*) AS the_count, sum(if(paidtodate>0,paidtodate,if(invoicetype='CPCN' or invoicetype='CPON' or invoicetype='CBCN' or invoicetype='CBON' or invoicetype='CPUB' or invoicetype='CPGU' or invoicetype='CPSO',invoiceamount,
fullinvoiceamount))) AS amount,
SUM(acis_cost) AS cost, (SUM(if(paidtodate>0,paidtodate,invoiceamount))-SUM(acis_cost)) AS profit FROM tblclientinvoices
Is there an SQLAlchemyish way to construct this query? - I've tried googling for Mysql IF statments with SQlAlchemy but drew blanks.
Many thanks!
Use func(documentation) to generate SQL function expression:
qry = select([
func.count().label("the_count"),
func.sum(func.IF(
Invoice.paidtodate>0,
Invoice.paidtodate,
# #note: I prefer using IN instead of multiple OR statements
func.IF(Invoice.invoicetype.in_(
("CPCN", "CPON", "CBCN", "CBON", "CPUB", "CPGU", "CPSO",)
),
Invoice.invoiceamount,
Invoice.fullinvoiceamount)
)
).label("amount"),
func.sum(Invoice.acis_cost).label("Cost"),
(func.sum(func.IF(
Invoice.paidtodate>0,
Invoice.paidtodate,
Invoice.invoiceamount
))
- func.sum(Invoice.acis_cost)
).label("Profit"),
],
)
rows = session.query(qry).all()
for row in rows:
print row

IF condition in mysql

I have a contact table I wish to query when a certain condition exists. I tried the query below but am getting a syntax error.
SELECT *
FROM contact_details
WHERE contactDeleted` =0
AND IF ( contactVisibility = "private"
, SELECT * FROM contact_details
WHERE contactUserId = 1
, IF( contactVisibility = "group"
, SELECT * FROM contact_details
WHERE contactGroup = 3
)
)
If I'm understanding your question correctly (which is difficult with the lack of info you've provided. Sample datasets and expected outcomes are typically helpful), then I don't believe you need IFs at all for what you want. The following will return contacts that are not deleted and who either have (visibility = "private" and userId = 1) OR (visibility = "group" and group = 3)
SELECT *
FROM contact_details
WHERE contactDeleted = 0
AND (
(contactVisibility = "public")
OR
(contactVisibility = "private" AND contactUserId = 1)
OR
(contactVisibility = "group" AND contactGroup = 3)
)
I am assuming you want to use the IF() function and not the statement which is for stored functions..
Refer to this link for more information on that.
Notice that you have put 2 select statements in there, where the custom return values are supposed to be. So you are returning a SELECT *... now notice that in your upper level sql statement you have an AND.. so you basically writing AND SELECT *.. which will give you the syntax error.
Try using .. AND x IN (SELECT *) .. to find if x is in the returned values.
Let me also list this link to make use of an existing and well written answer which may also applicable to your question.