I am working with sequelize. I want to select a substring in my where clause like this in SQL SUBSTRING(description_column, 1, 200). I am selecting by page, pagesize and limiting description_column to length of 200. I don't know if I can achieve it with raw query since I want pagination which findAll and FindAndCountAll offers which I want to use. How can I achieve this? The only substring I find in sequelize works this way
[Op.substring]: 'hat' // LIKE '%hat%'
You can use Sequelize.literal() to use the Standard SQL functions:
const options = {
attributes: [
'id',
sequelize.literal('SUBSTRING(description_column, 1, 200) as description_column')
]
}
MyTable.find(options).success(success);
Related
I've been trying to get full search text to work for a while now without any success. The current documentation has this example:
[Op.match]: Sequelize.fn('to_tsquery', 'fat & rat') // match text search for strings 'fat' and 'rat' (PG only)
So I've built the following query:
Title.findAll({
where: {
keywords: {
[Op.match]: Sequelize.fn('to_tsquery', 'test')
}
}
})
And keywords is defined as a TSVECTOR field.
keywords: {
type: DataTypes.TSVECTOR,
},
It seems like it's generating the query properly, but I'm not getting the expected results. This is the query that it's being generated by Sequelize:
Executing (default): SELECT "id" FROM "Tests" AS "Test" WHERE "Test"."keywords" ## to_tsquery('test');
And I know that there are multiple records in the database that have 'test' in their vector, such as the following one:
{
"id": 3,
"keywords": "'keyword' 'this' 'test' 'is' 'a'",
}
so I'm unsure as to what's going on. What would be the proper way to search for matches based on a TSVECTOR field?
It's funny, but these days I am also working on the same thing and getting the same problem.
I think part of the solution is here (How to implement PostgresQL tsvector for full-text search using Sequelize?), but I haven't been able to get it to work yet.
If you find examples, I'm interested. Otherwise as soon as I find the solution that works 100% I will update this answer.
What I also notice is when I add data (seeds) from sequelize, it doesn't add the lexemes number after the data of the field in question. Do you have the same behavior ?
last thing, did you create the index ?
CREATE INDEX tsv_idx ON data USING gin(column);
I need to find posts from the Post table where price property is either more than 1 value or lower than 2 value, min-max price kind of a thing, how to write a query for that? What should I write into the options object?
const posts = await this.postRepo.find({
where: {
price: Between(1, 100),
},
});
Can you try this? Or else you can also use createQueryBuilder to write more complex queries.
Designing a PostgreSQL database that will be queried by a Node API using Sequelize. Currently, I have a table called recipes that has columns called ingredients and instructions. Those columns are stored for a given as an array of strings like {Tomatoes, Onions}.
That method of storage worked fine for simply fetching and rendering a recipe on the client side. But it wasn't working well for fuzzy search querying because, using Sequelize all I could do was ingredients: { [Op.contains] : [query] }. So if a user typed tomatoes there was no way to write a "fuzzy" search query that would return a recipe with an ingredient Tomatoes.
And then I read this in the PostgreSQL documentation:
Arrays are not sets; searching for specific array elements can be a sign of database misdesign. Consider using a separate table with a row for each item that would be an array element. This will be easier to search, and is likely to scale better for a large number of elements.
Now I'm considering storing ingredients and instructions as separate tables, but I have a couple of questions.
1) As a recipe can have multiple ingredients related to it, should I just use a foreign key for each ingredient and the Sequelize hasMany relationship? That seems correct to me, except that I'm now potentially duplicating common ingredients each time a new recipe is created that uses that ingredient.
2) What would be the best way to write a fuzzy search query so that a user could search the main columns of the recipes table (e.g. title, description) and additionally apply their query to the instructions and ingredients tables?
Essentially I'd like to end up with a fuzzy search query applied to the three tables that looks something like this...
const recipes = await req.context.models.Recipe.findAll({
where: {
[Op.or]: [
{ title: { [Op.iLike]: '%' + query + '%' } },
{ description: { [Op.iLike]: '%' + query + '%' } },
{ ingredients: { ingredient: { [Op.iLike]: '%' + query + '%' } } },
{ instructions: { instruction: { [Op.iLike]: '%' + query + '%' } } }
]
}
});
Thanks!
I have done this, i happen to use graphql in my node layer with sequelize, and i have filter objects that do this type of thing. You'll just need some include statements in your Recipie.findAll.. after your initial where clause where you evaluate whether you are searching title or description or both type thing. i sent my search params in with prefix's i could strip off that told me what sequelize op's i would want to use on them and just ran my args through a utility method to create my where clause, but i know there are many ways to skin that cat. i just did not want to clutter up my resolvers with tonnes of hardcoded ops and conditional clauses was all.... your include might look something like this
include: [{
model: models.Ingredient,
as: 'Ingredients',
through: { some join table specifying keys where necessary since this
is many to many }
where: {some conditional code around your search param},
}, {
model: models.Instruction,
as: 'Instructions',
where: {some conditional code around your search param},
}],
There is good documentation around multiple includes, or nested includes in the sequelize docs, but from what i see above you have a fairly good understanding of what you need to do. To uncomplicate things a bit, i'd start with just searching on your fields from recipie (title, description) before you add the includes and get that working, then it will be a little clearer how you want to form your where clauses.
alternativley.. you can skip the includes and write associations in your models and call them with getters and pass the where clauses to those... i do that as well and again well documented stuff now.. Sequelize has really upped their game
Recipie.associate = function (models) {
models.Recipie.hasMany(models.Ingredient, { as: 'Ingredients', through: "recipie_ingredient" foreignKey: 'recipie_id'});
};
now you have a getter for Ingredients, and if you declare belongsToMany targetting back at Recipie in the Ingredient model then you'll have a getter there as well, and you can pass your search string to that via where clause and get all recipies that have a given ingredient or ingredient list type thing.... Clear as mud?
So I have an embedded document that tracks group memberships. Each embedded document has an ID pointing to the group in another collection, a start date, and an optional expire date.
I want to query for current members of a group. "Current" means the start time is less than the current time, and the expire time is greater than the current time OR null.
This conditional query is totally blocking me up. I could do it by running two queries and merging the results, but that seems ugly and requires loading in all results at once. Or I could default the expire time to some arbitrary date in the far future, but that seems even uglier and potentially brittle. In SQL I'd just express it with "(expires >= Now()) OR (expires IS NULL)" -- but I don't know how to do that in Mongo.
Any ideas? Thanks very much in advance.
Just thought I'd update in-case anyone stumbles across this page in the future. As of 1.5.3, mongo now supports a real $or operator: http://www.mongodb.org/display/DOCS/Advanced+Queries#AdvancedQueries-%24or
Your query of "(expires >= Now()) OR (expires IS NULL)" can now be rendered as:
{$or: [{expires: {$gte: new Date()}}, {expires: null}]}
In case anyone finds it useful, www.querymongo.com does translation between SQL and MongoDB, including OR clauses. It can be really helpful for figuring out syntax when you know the SQL equivalent.
In the case of OR statements, it looks like this
SQL:
SELECT * FROM collection WHERE columnA = 3 OR columnB = 'string';
MongoDB:
db.collection.find({
"$or": [{
"columnA": 3
}, {
"columnB": "string"
}]
});
MongoDB query with an 'or' condition
db.getCollection('movie').find({$or:[{"type":"smartreply"},{"category":"small_talk"}]})
MongoDB query with an 'or', 'and', condition combined.
db.getCollection('movie').find({"applicationId":"2b5958d9629026491c30b42f2d5256fa8",$or:[{"type":"smartreply"},{"category":"small_talk"}]})
Query objects in Mongo by default AND expressions together. Mongo currently does not include an OR operator for such queries, however there are ways to express such queries.
Use "in" or "where".
Its gonna be something like this:
db.mycollection.find( { $where : function() {
return ( this.startTime < Now() && this.expireTime > Now() || this.expireTime == null ); } } );
db.Lead.find(
{"name": {'$regex' : '.*' + "Ravi" + '.*'}},
{
"$or": [{
'added_by':"arunkrishna#aarux.com"
}, {
'added_by':"aruna#aarux.com"
}]
}
);
Using a $where query will be slow, in part because it can't use indexes. For this sort of problem, I think it would be better to store a high value for the "expires" field that will naturally always be greater than Now(). You can either store a very high date millions of years in the future, or use a separate type to indicate never. The cross-type sort order is defined at here.
An empty Regex or MaxKey (if you language supports it) are both good choices.
I am writing a node.js application using express, mongodb, and monk.
When I do a find with criteria only or with projections only, I get the expected result, but when I do a find with both, the full documents are returned, i.e., the projection is not performed. My code looks like this:
var collection = db.get('myDB');
collection.find({field1: "value"},{field2: 1, _id: 0},function(e,docs) {
...do stuff with docs...
});
It returns not just field2 but all fields of all the docs matching the criterion on field1. I can get field2 from this, but I don't like the inefficiency of it.
Is there a way to use both criteria and projections?
Monk uses a space-delimited string for field projection where you prefix a field name with - to exclude it.
So it should be:
var collection = db.get('myDB');
collection.find({field1: "value"}, 'field2 -_id', function(e,docs) {
...do stuff with docs...
});