SQLAlchemy SELECT id FROM Table_1 WHERE name='xyz' - sqlalchemy

I can get the SELECT id from parts where name='Part1' as an SQL statement but what is the way to do that with SQLAlchemy?
I've tried;
db.session.query(Parts.id).filter(name=form.name.data)
But this returns an Object not the id

Use the below code.
parts = db.session.query(Parts).filter(Parts.name==Part1).first()
Then if you want the only id you can just access
parts.id

Store that object in a varaible, and then use dot notation to pull out what you want. For example:
item = db.session.query(Parts.id).filter(name=form.name.data).one()
print item.id

Related

SELECT statement inside a CASE statement in SNOWFLAKE

I have a query where i have "TEST"."TABLE" LEFT JOINED to PUBLIC."SchemaKey". Now in my final select statement i have a case statement where i check if c."Type" = 'FOREIGN' then i want to grab a value from another table but the table name value i am using in that select statement is coming from the left joined table column value. I've tried multiple ways to get to work but i keep getting an error, although if i hard code the table name it seems to work. i need the table name to come from c."FullParentTableName". Is what i am trying to achieve possible in snowflake and is there a way to make this work ? any help would be appreciated !
SELECT
c."ParentColumn",
c."FullParentTableName",
a."new_value",
a."column_name"
CASE WHEN c."Type" = 'FOREIGN' THEN (SELECT "Name" FROM TABLE(c."FullParentTableName") WHERE "Id" = 'SOME_ID') ELSE null END "TestColumn" -- Need assistance on this line...
FROM "TEST"."TABLE" a
LEFT JOIN (
select s."Type", s."ParentSchema", s."ParentTable", s."ParentColumn", concat(s."ParentSchema",'.','"',s."ParentTable",'"') "FullParentTableName",s."ChildSchema", s."ChildTable", trim(s."ChildColumn",'"') "ChildColumn"
from PUBLIC."SchemaKey" as s
where s."Type" = 'FOREIGN'
and s."ChildTable" = 'SOMETABLENAME'
and "ChildSchema" = 'SOMESCHEMANAME'
) c
on a."column_name" = c."ChildColumn"
Thanks !
In Snowflake you cannot dynamically use the partial results as tables.
You can use a single bound value via identifier to bind a value to table name
But you could write a Snowflake Scripting but it would need to explicitly join the N tables. Thus if you N is fixed, you should just join those.

How to access columns of subqueries with jooq?

i am having troubles understanding how to access columns from a subquery (MySQL). Here is my code:
Personne personne = Personne.PERSONNE.as("personne");
Evenement evenement = Evenement.EVENEMENT.as("evenement");
Genealogie genealogie = Genealogie.GENEALOGIE.as("genealogie");
Lieu lieu = Lieu.LIEU.as("lieu");
SelectField<?>[] select = { DSL.countDistinct(personne.ID).as("countRs"), lieu.LIBELLE.as("libelleRs"),
lieu.ID.as("idVille") };
Table<?> fromPersonne = evenement.innerJoin(personne).on(personne.ID.eq(evenement.IDPERS))
.innerJoin(genealogie).on(genealogie.ID.eq(personne.IDGEN)).innerJoin(lieu)
.on(lieu.ID.eq(evenement.IDLIEU));
Table<?> fromFamille = evenement.innerJoin(personne).on(personne.IDFAM.eq(evenement.IDFAM))
.innerJoin(genealogie).on(genealogie.ID.eq(personne.IDGEN)).innerJoin(lieu)
.on(lieu.ID.eq(evenement.IDLIEU));
GroupField[] groupBy = { lieu.ID };
Condition condition = //conditionally build, not relevant i think
result = create.select(DSL.asterisk())
.from(create.select(select).from(fromPersonne).where(condition).groupBy(groupBy)
.union(create.select(select).from(fromFamille).where(condition).groupBy(groupBy)))
// i would like something like this but i don't know how: .groupBy(groupBy).fetch();
Basicly what i have is:
SELECT
*
FROM(
(SELECT
countRs, libelleRs, idVille
FROM
fromPersonne
WHERE
-- conditions
GROUP BY lieu.ID)
UNION
(SELECT
countRs, libelleRs, idVille
FROM
fromFamille
WHERE
-- conditions
GROUP BY lieu.ID)
)GROUP BY lieu.ID -- this is where i need help
In a plain MySQL query i would just give an alias to the union and then make a reference to the column i want to group by using the alias but it seems like it does not work like this with JOOQ.
I just need to group the results of the subqueries together but i don't know how to make a reference to the subqueries columns... I am sure i would have to reference my subqueries in objects outside of that "main select" to be able to access the columns or something along those lines but i am lost in all the object types.
You have to assign your derived table to a local variable and dereference columns from it, e.g.
Table<?> t = table(
select(...).from(...).groupBy(...).unionAll(select(...).from(...).groupBy(...))
).as("t");
Field<Integer> tId = t.field(lieu.ID);

MySQL where if statement

I'm currently working on an API using node.js and node-mysql.
I start off by grabbing all the parameters that the client sends over like this:
var userId = req.query.userId;
var carType = req.query.carType;
var hasOwnership = req.query.hasOwnership; (optional parameter)
What I would like to do is make a statement so that if the client sends the hasOwnership parameter with the request, my statement will return all the cars that belong to him with the specific car type. Similar to this:
SELECT * FROM cars WHERE car_type=? AND owner_id=?, [carType, userId];
Otherwise it will just return the all the cars that match the car type:
SELECT * FROM cars WHERE car_type=?, [carType];
Is it possible to accomplish something like this in a single query?
Thanks in advance!
You can phrase the query as something like this:
SELECT *
FROM car
WHERE (? is null or car_type = ?) AND
(? is null or owner_id = ?);
Note that this version takes each parameter twice, unless you use named parameters.
A dirty quick solution would be to use an if then else.
if hasOwnership has value the use query #1 else use query #2

Django select distinct in mysql

How would I do the following query in django:
Asset.objects.all().distinct('checksum') # get all distinct checksum items
The equivalent in SQL would be:
SELECT * FROM asset GROUP BY checksum
Note that I need all fields here, so I cannot do something like Asset.objects.values_list('checksum').distinct(). How would I do this?
Do you want to get the first item of every checksum?
items = Asset.objects.all()
items.query.group_by = ['checksum']
print items
[<Asset: ...]

MySql dynamic column name

[major edit to make things clear]
I want to write a query that returns a dynamic column name like this:
SELECT
f2 AS
(
SELECT column_name
FROM column_names_tbl
WHERE column_name = "experience"
limit 0,1
)
FROM some_table
so that would output the same as this:
SELECT
f2 AS experience
FROM some_table
This is no correct SQL syntax, even because the two queries (the selected field and it's alias) are both subqueries and unrelated to each other. So, there's also no possibility for mysql to distinguish what name you want to connect to what value, even if the syntax was correct...
You already use a more or less normalized relational table, so I suggest the following solution:
you select the revision ID and name in a separate query; store them in PHP and use them for whatever you want
next, you evaluate the following query into a separated result set: SELECT ps.keyname, psv.keyvalue FROM page_setting_values AS psv INNER JOIN page_settings AS ps ON ps.id = psv.setting_id WHERE psv.page_revision_id = :revision with :revision representing your revision id
you may now assemble an associated array from that result set:
$settings = [];
$result = $db->executeQuery('...')->fetchAll();
foreach($result as $setting)
{
$settings[$setting['keyname']] = $setting['keyvalue'];
}
Hope that helps ;)