I have a sequelize query that looks like
const deliveriesToCancel = await Model.ShipperContract.findByPk(organizationId, {
include: [
{
model: Model.Order,
as: organizationId,
include: [
{
model: Model.Delivery,
as: "deliveries",
where: {
state: {
[Op.not]: "DELIVERED" || "CANCELED_BYL" || "CANCELED_BY_SHIPPER"
}
}
},
],
},
],
});
Is it possible to query on Delivery table with 3 possible choices for state column? or in this case, WHERE !== those 3 values?
How can I write taht in seqeulize?
If you want to select the deliveries where "state" isn't any of "DELIVERED", "CANCELED_BYL", or "CANCELED_BY_SHIPPER", you can use:
where: {
state: {
[Op.notIn]: ["DELIVERED", "CANCELED_BYL", "CANCELED_BY_SHIPPER"]
}
}
Note:
WHERE NOT IN can be slow. If your dataset is huge and your query is slow, consider looking into modifying it to an exists. Docs, Docs
Related
I am new to MongoDB. I need to convert this SQL code to MongoDB
select TOP 5 r.regionName, COUNT(c.RegionID)
from region as r,
company as c
where c.RegionID = r._id
group by r.regionName
order by COUNT(c.RegionID) DESC;
Option 1. You can use the aggregation framework with $lookup, $group, $project , $sort and $limit stages, but this seems like a wrong approach since the true power to change relation database with mongoDB is the denormalization and avoidance of join ($lookup) like queries.
Option 2. You convert your multi-table relational database schema to document model and proceed with simple $group, $project, $sort and $limit stage aggregation query for the above task.
Since you have not provided any mongodb document examples it is hard to provide how your queries will look like ...
Despite of my comment I try to give a translation (not tested):
db.region.aggregate([
{
$lookup: // left outer join collections
{
from: "company",
localField: "_id",
foreignField: "RegionID",
as: "c"
}
},
{ $match: { c: { $ne: [] } } }, // remove non-matching documents (i.e. INNER JOIN)
{ $group: { _id: "$regionName", regions: { $addToSet: { "$c.RegionID" } } } }, // group and get distinct regions
{ $project: { regionName: "$_id", count: { $size: "$regions" } , _id: 0} } // some cosmetic and count
{ $sort: { regionName: 1 } }, // order result
{ $limit: 5 } // limit number or returned documents
])
I have two documents on mongodb, these are percentages and items. I'm good at SQL, I can write PLSql query as follows but i can not convert to mongodb query. Because my mongodb level of knowledge is at the beginning. Actually I know I have to use $gt for the and condition. But I don't know how I can say not exists or union keyword for mongodb. How can I write mongodb query? which keywords should i search for?
select p.*, "to_top" as list
from percentages p
where p.percentage > 5
and p.updatetime > sysdate - 1/24
and not exists (select 1
from items i
where i.id = p.p_id
and i.seller = p.seller)
order by p.percentage desc
union
select p2.*, "to_bottom" as list
from percentages p2
where p2.percentage > 5
and p2.updatetime > sysdate - 1/24
and exists (select 1
from items i2
where i2.id = p2.p_id
and i2.seller = p2.seller)
order by p2.percentage desc
There is no UNION for MongoDB. Luckely, each query is performed on the same collection and have very close condition, so we can implement "Mongo way" query.
Explanation
Normally, alsmost all complex SQL queries are done with the MongoDB aggregation framework.
We filter document by percentage / updatetime. Explanation why we need to use $expr
SQL JOIN / Subquery is done with the $lookup operator.
SQL SYSDATE in MongoDB way can be NOW or CLUSTER_TIME variable.
db.percentages.aggregate([
{
$match: {
percentage: { $gt: 5 },
$expr: {
$gt: [
"$updatetime",
{
$subtract: [
ISODate("2020-06-14T13:00:00Z"), //Change to $$NOW or $$CLUSTER_TIME
3600000
]
}
]
}
}
},
{
$lookup: {
from: "items",
let: {
p_id: "$p_id",
seller: "$seller"
},
pipeline: [
{
$match: {
$expr: {
$and: [
{
$eq: [ "$$p_id", "$id"]
},
{
$eq: [ "$$seller", "$seller"]
}
]
}
}
},
{
$limit: 1
}
],
as: "items"
}
},
{
$addFields: {
list: {
$cond: [
{
$eq: [{$size: "$items"}, 0]
},
"$to_top",
"$to_bottom"
]
},
items: "$$REMOVE"
}
},
{
$sort: { percentage: -1 }
}
])
MongoPlayground
Note: The MongoDB aggregation has the $facet operator that allows to perform different queries on the same collection.
SCHEMA:
db.percentages.aggregate([
{$facet:{
q1:[...],
q2:[...],
}},
//We apply "UNION" the result documents for each pipeline into single array
{$project:{
data:{$concatArrays:["$q1","$q2"]}
}},
//Flatten array into single object
{$unwind:"$data"}
//Replace top-level document
{$replaceWith:"$data"}
])
MongoPlayground
why you don't import your mangoDB data into oracle and use sql(that is more easy and powerful than mango.)
I'm struggling in how to select from two tables using the Sequelize.
Actually I'm trying to do it:
SELECT * FROM users, clients WHERE user.id = clients.user_id
I have no idea how to user two tables as I described, the only thing I did that got some results were:
const clients = await Client.findAll({
attributes: ["user_id"],
});
const users = [];
for (const client of clients) {
let user = await User.findAll({
where: {
id: {
[Op.eq]: client.user_id
}
}
});
users.push(user);
}
Which return me something:
[
[
{
"id": 1,
"first_name": "Velda",
"middle_name": "Zboncak",
"last_name": "Kris",
"email": "vkris10#hotmail.com",
"created_at": "2020-02-07T20:09:29.484Z",
"updated_at": "2020-02-07T20:09:29.484Z"
}
]
];
Model and Assossiation
First of all, you need to create the correct associations in the model of your table. In this case for the User and the Client, it's supposed to be an Client.belongsTo(...)
Take a look at User model:
const { Model, DataTypes } = require("sequelize");
class User extends Model {
static init(sequelize) {
super.init({
first_name: DataTypes.STRING,
middle_name: DataTypes.STRING,
last_name: DataTypes.STRING,
email: DataTypes.STRING
}, { sequelize });
}
}
module.exports = User;
Take a look at Client model:
const { Model, DataTypes } = require("sequelize");
class Client extends Model {
static init(sequelize) {
super.init({
user_id: DataTypes.INTEGER // The foreign key
}, { sequelize });
}
static associate(models) {
Client.belongsTo(models.User, {
foreignKey: "id", // Column name of associated table
as: "user" // Alias for the table
});
}
}
module.exports = Client;
When associating tables you need to have in mind those values inside the associate method, being the foreignKey: "id" the column name inside the models.ModelName, which will be used to make the joins, and the as: "user" which are used as an alias for the table like SELECT t.column1 FROM table AS t;
Controller
Okay, now you have set your models, you need to set your controller, where the magic happens. As you said you want to fetch results using:
SELECT * FROM users, clients WHERE user.id = clients.user_id
But to achieve the same result you can follow the sql join method to fetch the results from db, so it will be something like this:
SELECT
"user"."first_name", "user"."middle_name", "user"."last_name", "user"."email"
FROM "clients" AS "client"
LEFT JOIN "users" AS "user"
ON "client"."id" = "user"."id";
Knowing that we can talk about including tables in sequelize, which is the same as associations
const Client = require("./path/to/models/Client");
module.exports = {
async fetchAll(req, res) {
const results = await Client.findAll({
limit: 25,
include: [
{
association: "user",
attributes: ["first_name", "middle_name", "last_name", "email"]
}
]
});
return res.json(results);
},
};
Now lets talk about what is going on in the code:
The Model.findAll({}) will fetch all the result inside the specified table, in this case clients table.
The limit: 25 will limit your results in only 25 rows, you are free to remove or edit as you need.
The include: [], it will do the joins through the tables you specify, as you need only the users table, we are going to use only one object, so the assossiation: "user" will make this connection between tables, you must use the same alias you set inside the model. And at least the attributes: ["columns"] is where you set all the fields you want to fetch.
And that's it, you make you request, and the result of this will be exactly the same join as I mentioned. And the results will be:
[
{
"id": 1,
"user_id": 1,
"user": {
"first_name": "John",
"middle_name": "Ironsight",
"last_name": "Doe",
"email": "johndoe#example.com"
}
}, {...}
]
Can use where in include. Find the document at here
let user_id = client.user_id;
users = await User.findAll({
include: [
{
model: Client,
as: 'client',
where: {
user_id: user_id
}
}
]
});
My team started to use MongoDB now and wanna migrate some sql to Mongo.
For example, I have an order table and has the fields price and quanty.I want to query the price*quanty greater than 100. sql is like below
select * from Order where price * quanty > 100;
How to use "price * quanty" this kind query in Mongo?
Thanks.
You can do this by using the $expr operator to use aggregation expressions within your query:
db.orders.find({
$expr: {
$gt: [
{ $multiply: ["$price", "$quantity"] },
100
]
}
})
As JohnnyHK points out you can use $expr, but as an alternative you can also use aggregation to first create a new field that is the product of two other fields:
db.orders.aggregate([
{ $set: { product: { $multiply: [ "$price", "$quantity" ] } } }
])
Note: $set is new in 4.2 and just an alias for $addFields
Then add a $match stage that only matches documents with the new product field meeting your condition:
db.orders.aggregate([
{ $set: { product: { $multiply: [ "$price", "$quantity" ] } } },
{ $match: { product: { $gt: 100 } } }
])
provided that I have following statement in sequelize
return models.VehicleModel
.findAll({
include: [
{
attributes: ['id'],
model: models.Unit
},
{
model: models.myPattern,
where: {
VehicleModelId: { $in: data.VehicleModelIds }
},
include: [
{
model: models.Calendar,
include: [
{
model: models.Restrictions,
include: [
{
model: models.RestrictionType
}],
where: {
//THIS IS THE LINE I NEED TO CHANGE SOMEHOW
UnitId: { $in: [models.Unit.id] }
},
required: false
}
]
}
]
}
],
where: {
id: { $in: data.VehicleModelIds }
}
})
This gives me NULL in the query like so:
[myPattern.Calendar.Restrictions].UnitId IN (NULL) AND ....
I want to be able to get the following instead:
[myPattern.Calendar.Restrictions].UnitId IN (Units.id) AND ....
This is because they are not mandatory to be there but should of course be linked to the proper unit corresponding to the vehicle model.
The myPattern is linked to the Calendar who is in turn linked to the Restrictions and so to the Units.
This all using id column.
Any help would be appreciated!
Found it
So for people looking for the "how to":
//...
where: {
UnitId: { $in: [models.sequelize.literal('Units.id')] },
}
//...and so on
This will output in the query: [myPattern.Calendar.Restrictions].UnitId IN (Units.id)