Grabbing array-like data via SQL joins to form complete object
I have the following three tables:
drinks: id | name
ingredient: id | name
drink_ingredients: drinks.id | ingredients.id
When I create a "drink", I provide an array of ingredient ids as well. The relationship here is managed by the drink_ingredients table, which allows me to reuse ingredients.
I'm trying to create a query of which will return data representing the following:
drink ingredients: [2, 3]
Essentially meaning I would like to extract out the ingredient id attached to this drink and return them as an array.
I currently have
select * from "drinks" inner join "drink_ingredients" on "drinks"."id" = "drink_ingredients"."drink_id"
I'm still missing the step to retrieve the data from ingredients, but as well this, this returns:
"id": 0,
"owner": 18,
"name": "Coffee",
"drink_id": 0,
"ingredient_id": 2
,
"id": 0,
"owner": 18,
"name": "Coffee",
"drink_id": 0,
"ingredient_id": 3
,
Is it possible to correctly embed data this way in a single statement?
sql postgresql node-postgres
asked Nov 11 '18 at 21:08
N.J.Dawson
498419
add a comment |
I have the following three tables:
drinks: id | name
ingredient: id | name
drink_ingredients: drinks.id | ingredients.id
When I create a "drink", I provide an array of ingredient ids as well. The relationship here is managed by the drink_ingredients table, which allows me to reuse ingredients.
I'm trying to create a query of which will return data representing the following:
drink ingredients: [2, 3]
Essentially meaning I would like to extract out the ingredient id attached to this drink and return them as an array.
I currently have
select * from "drinks" inner join "drink_ingredients" on "drinks"."id" = "drink_ingredients"."drink_id"
I'm still missing the step to retrieve the data from ingredients, but as well this, this returns:
"id": 0,
"owner": 18,
"name": "Coffee",
"drink_id": 0,
"ingredient_id": 2
,
"id": 0,
"owner": 18,
"name": "Coffee",
"drink_id": 0,
"ingredient_id": 3
,
Is it possible to correctly embed data this way in a single statement?
sql postgresql node-postgres
asked Nov 11 '18 at 21:08
N.J.Dawson
498419
add a comment |
I have the following three tables:
drinks: id | name
ingredient: id | name
drink_ingredients: drinks.id | ingredients.id
When I create a "drink", I provide an array of ingredient ids as well. The relationship here is managed by the drink_ingredients table, which allows me to reuse ingredients.
I'm trying to create a query of which will return data representing the following:
drink ingredients: [2, 3]
Essentially meaning I would like to extract out the ingredient id attached to this drink and return them as an array.
I currently have
select * from "drinks" inner join "drink_ingredients" on "drinks"."id" = "drink_ingredients"."drink_id"
I'm still missing the step to retrieve the data from ingredients, but as well this, this returns:
"id": 0,
"owner": 18,
"name": "Coffee",
"drink_id": 0,
"ingredient_id": 2
,
"id": 0,
"owner": 18,
"name": "Coffee",
"drink_id": 0,
"ingredient_id": 3
,
Is it possible to correctly embed data this way in a single statement?
sql postgresql node-postgres
asked Nov 11 '18 at 21:08
N.J.Dawson
498419
I have the following three tables:
drinks: id | name
ingredient: id | name
drink_ingredients: drinks.id | ingredients.id
When I create a "drink", I provide an array of ingredient ids as well. The relationship here is managed by the drink_ingredients table, which allows me to reuse ingredients.
I'm trying to create a query of which will return data representing the following:
drink ingredients: [2, 3]
Essentially meaning I would like to extract out the ingredient id attached to this drink and return them as an array.
I currently have
select * from "drinks" inner join "drink_ingredients" on "drinks"."id" = "drink_ingredients"."drink_id"
I'm still missing the step to retrieve the data from ingredients, but as well this, this returns:
"id": 0,
"owner": 18,
"name": "Coffee",
"drink_id": 0,
"ingredient_id": 2
,
"id": 0,
"owner": 18,
"name": "Coffee",
"drink_id": 0,
"ingredient_id": 3
,
Is it possible to correctly embed data this way in a single statement?
sql postgresql node-postgres
sql postgresql node-postgres
asked Nov 11 '18 at 21:08
N.J.Dawson
498419
asked Nov 11 '18 at 21:08
N.J.Dawson
498419
asked Nov 11 '18 at 21:08
N.J.Dawson
498419
asked Nov 11 '18 at 21:08
N.J.Dawson
498419
asked Nov 11 '18 at 21:08
N.J.Dawson
498419
498419
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
This can be done using the array_agg function:
select d.id, d.name, array_agg(di.ingredient_id) as ingredients
from drinks d
left outer join drink_ingredients di on di.drink_id = d.id
group by d.id, d.name
As you (per your question) only want the array of ingredient-ids, you don't even need to join with ingredients. The left join is just in case you have a drink with no ingredients (water?).
answered Nov 11 '18 at 21:44
Henning Koehler
1,129610
I dreamed bigger and managed to get the JSON representation of my objects in their complete form rather than IDs. Your help on the join was what got me there, thanks very much for your assistance and concise answer!
– N.J.Dawson
Nov 12 '18 at 20:51
add a comment |
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1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
This can be done using the array_agg function:
select d.id, d.name, array_agg(di.ingredient_id) as ingredients
from drinks d
left outer join drink_ingredients di on di.drink_id = d.id
group by d.id, d.name
As you (per your question) only want the array of ingredient-ids, you don't even need to join with ingredients. The left join is just in case you have a drink with no ingredients (water?).
answered Nov 11 '18 at 21:44
Henning Koehler
1,129610
I dreamed bigger and managed to get the JSON representation of my objects in their complete form rather than IDs. Your help on the join was what got me there, thanks very much for your assistance and concise answer!
– N.J.Dawson
Nov 12 '18 at 20:51
add a comment |
This can be done using the array_agg function:
select d.id, d.name, array_agg(di.ingredient_id) as ingredients
from drinks d
left outer join drink_ingredients di on di.drink_id = d.id
group by d.id, d.name
As you (per your question) only want the array of ingredient-ids, you don't even need to join with ingredients. The left join is just in case you have a drink with no ingredients (water?).
answered Nov 11 '18 at 21:44
Henning Koehler
1,129610
I dreamed bigger and managed to get the JSON representation of my objects in their complete form rather than IDs. Your help on the join was what got me there, thanks very much for your assistance and concise answer!
– N.J.Dawson
Nov 12 '18 at 20:51
add a comment |
This can be done using the array_agg function:
select d.id, d.name, array_agg(di.ingredient_id) as ingredients
from drinks d
left outer join drink_ingredients di on di.drink_id = d.id
group by d.id, d.name
As you (per your question) only want the array of ingredient-ids, you don't even need to join with ingredients. The left join is just in case you have a drink with no ingredients (water?).
answered Nov 11 '18 at 21:44
Henning Koehler
1,129610
This can be done using the array_agg function:
select d.id, d.name, array_agg(di.ingredient_id) as ingredients
from drinks d
left outer join drink_ingredients di on di.drink_id = d.id
group by d.id, d.name
As you (per your question) only want the array of ingredient-ids, you don't even need to join with ingredients. The left join is just in case you have a drink with no ingredients (water?).
answered Nov 11 '18 at 21:44
Henning Koehler
1,129610
answered Nov 11 '18 at 21:44
Henning Koehler
1,129610
answered Nov 11 '18 at 21:44
Henning Koehler
1,129610
answered Nov 11 '18 at 21:44
Henning Koehler
1,129610
1,129610
I dreamed bigger and managed to get the JSON representation of my objects in their complete form rather than IDs. Your help on the join was what got me there, thanks very much for your assistance and concise answer!
– N.J.Dawson
Nov 12 '18 at 20:51
add a comment |
I dreamed bigger and managed to get the JSON representation of my objects in their complete form rather than IDs. Your help on the join was what got me there, thanks very much for your assistance and concise answer!
– N.J.Dawson
Nov 12 '18 at 20:51
I dreamed bigger and managed to get the JSON representation of my objects in their complete form rather than IDs. Your help on the join was what got me there, thanks very much for your assistance and concise answer!
– N.J.Dawson
Nov 12 '18 at 20:51
I dreamed bigger and managed to get the JSON representation of my objects in their complete form rather than IDs. Your help on the join was what got me there, thanks very much for your assistance and concise answer!
– N.J.Dawson
Nov 12 '18 at 20:51
add a comment |
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