I already tried setting the name property on the createIndex function but still it use the prefix _design on index id;
db.createIndex({
index: {
fields: ['index.barcode'],
name: 'myprefixname',
ddoc: 'product_index_barcode',
},
})
And on the createIndex options I only see this options fields, name, ddoc, type and partial_filter_selector.
Is there documentation I missed on how to changed the index _id to a custom prefix?
Related
To create a unique index in sequelize migrations we can do something like below,
await queryInterface.addIndex(SCHOOL_TABLE, {
fields: ['name', 'school_id'],
unique: true,
name: SCHOOL_NAME_ID_UNIQUE_INDEX,
where: {
is_deleted: false
},
transaction,
})
The problem is It allows duplicates due to case senstivity.
In the doc here, It is mentioned that fields should be an array of attributes.
How can I apply lower() to name field so that It can become case insensitive?
I am using a workaround for now, using raw query. I don't think addIndex() supports using functions on fields.
await queryInterface.sequelize.query(`CREATE UNIQUE INDEX IF NOT EXISTS ${SCHOOL_NAME_ID_UNIQUE_INDEX}
ON ${SCHEMA}.schools USING btree (lower(name), school_id) where is_deleted = false;
`, { transaction});
I have a school schema like this:
var SchoolSchema= new mongoose.Schema({
name: {type:String, required: true}
status: { type: String, default: "active" }
});
Mongoose default feature works on two levels:
1) Set field value to default while saving, if the field is not present in the input.
2) While fetching, set field value to default value, if the field is not present in the saved document.
What I wish is for it to set it to default value only while saving, and when fetching a document it should return null value for status if the status property is not present in the record. Currently it returns 'active' when I remove status property from the record.
Is there a way I could do this Mongoose?
What you can do is use the pre-save middleware.
It would look something like this:
schema.pre('save', function(next) {
// Change your fields
next()
})
This code will be activated when you save your mongo document.
Mongoose also adds a isNew field to your object so you could extend this code to only change your fields if this is the first time the document is being save to the DB
schema.pre('save', function(next) {
if (this.isNew) {
// Change your fields
}
next()
})
I see in all examples the suffix "_id" on a field referencing to another document.
Example:
record: {
_id : ObjectId("57f2fb5d1c6c3b0de45b170e",
artist_id: "prince" )
}
artist: {
_id: "prince"
}
Being that my artist mongo Schema has the "unique" attribute on the name field.
Is it Ok to things like below ?
record: {
_id : ObjectId("57f2fb5d1c6c3b0de45b170e",
artist: "prince" )
}
artist: {
_id : ObjectId(6eygdqzd5d1c6c3b0de45b1s0r",
name: "prince"
}
Or should you always reference directly the Id like in the first example?
if you visualize your problem in RDBMS world, there too to establish a foreign key constraint the field should be primary key in the referenced table and the same rule applies here.
now in your artist document though each document is going to contain a unique artist name but the name field itself is not key (primary key) but the ID is.
hence you have to establish the reference using the _id field.
what you can do is for ease if you want rather than relying on the mongodb generated ID field you can probably use name as the _id.
I have an index 'user' which has a mapping with field of "first", "last", and "email". The fields with names get indexed at one point, and then the field with the email gets indexed at a separate point. I want these indices to have the same id though, corresponding to one user_id parameter. So something like this:
function indexName(client, id, name) {
return client.update({
index: 'user',
type: 'text',
id: id,
body: {
first: name.first
last: name.last
}
})
}
function indexEmail(client, id, email) {
return client.update({
index: 'user',
type: 'text',
id: id,
body: {
email: email
}
})
}
When running:
indexName(client, "Jon", "Snow").then(indexEmail(client, "jonsnow#gmail.com"))
I get an error message saying that the document has not been created yet. How do I account for a document with a variable number of fields? And how do I create the index if it has not been created and then subsequently update it as I go?
The function you are using, client.update, updates part of a document. What you actually needs is to first create the document using the client.create function.
To create and index, you need the indices.create function.
About the variable number of fields in a document type, it is not a problem because Elastic Search support dynamic mapping. However, it would be advisable to provide a mapping when creating the index, and try to stick to it. Elastic Search default mapping can create you problems later on, e.g. analyzing uuids or email addresses which then become difficult (or impossible) to search and match.
I am trying to stop duplicates in my Mongo DB Collection but they are still getting in. I am reading data from twitter and storing it like:
var data = {
user_name: response[i].user.screen_name,
profile_image: response[i].user.profile_image_url,
content: {
text: response[i].text
},
id: response[i].id_str,
};
and I have the following to stop any duplicates:
db[collection].ensureIndex( { id: 1, "content.text": 1 }, { unique: true, dropDups: true } );
The id field is working and no duplicates appear but "content.text" field does not work and duplicates are appearing. Any Ideas why?
When you enforce a unique constraint on a composite index, two documents are considered same only if the documents have the same value for both id and context.text fields and not for either key individually.
To enforce unique constraints on the fields, id and context.text individually, You could enforce it as below:
db.col.ensureIndex({"id":1},{unique:true}) and similarly for the other field.