I tried to find a way to copy/clone instances in Sequelize but without success. Is there any way to do it with a built-in function or without? What I want is to simply copy rows in the database and the new item should have only a different id.
There is no such direct function for that , What you can do is :
Fetch the object that you want to clone/copy
Remove Primary Key from it
Make a new entry from it
model.findOne({ //<---------- 1
where : { id : 1 } ,
raw : true })
.then(data => {
delete data.id; //<---------- 2
model.create(data); //<---------- 3
})
As said, there is no such direct function for that (thanks Vivek)
If you find useful, place the following code on your model class:
async clone() {
let cData = await THISISMYMODEL.findOne({
where: { id: this.id},
raw: true,
});
delete cData.id;
return await THISISMYMODEL.create(data);
}
Take into account that "THISISMYMODEL" should be the model class defined and "id" the primary key attribute used.
Also take into account the use of Foreign Keys (relations with other models), it will use the same keys. Otherwise you should clone those instances too.
You may need to update the name though or some other field to identify it as a copy,
const data = await model.findOne({ where: {id: 1}, raw: true, attributes: { exclude: ['id'] } });
data.name = data.name + '(copy)';
const newRecord = await model.create(data);
Write a Model.create(data) function inside Model.js and call this function from inside of a loop, as many times you need it will create the copy of the same data.
Related
I am try to track the number of downloads per click on a website.
server.js
router.post("/download", async (req, res) => {
let id = req.body.id;
id = parseInt(id);
let doc = await db.findOneAndUpdate({_id: id}, {downloads: 100});
});
Note: This works
But I'm trying to increase the number by 1 each time.
For example: Let's say the current number of downloads is 5, how do I do it that if there's a post request. The number of downloads increases by 1.
const { body: { id } } = req;
const intCasetedId = parseInt(id);
const retrievedDocument = await db.findOneAndUpdate({ id }, { $inc: { downloads: 1 } });
A couple things are happening here.
First I get the id value from the the req argument using a destructuring assignment.
I use only const to ensure I do not mutate variable values.
I also use the object property value shorthand notation to skip '_id' key in the search query argument. Quoting mongoose documentation:
Issues a mongodb findAndModify update command by a document's _id field. findByIdAndUpdate(id, ...) is equivalent to findOneAndUpdate({ _id: id }, ...).
Then I am using '$inc' operator to increment the downloads field by 1.
I would also highly recommend for you to research eslint
I'm trying to update a column in users table the column type is json.
column name is test.
and the column consists of an object default value for example is
{a: "text", b: 0}
how to update let's say the object key b without changing the whole column
the code i'm using is
knexDb('users').where({
email: email
})
.update({
test: { b: 1 }
})
second solution
knexDb('users').where({
email: email
})
.update({
test: knexDb.raw(`jsonb_set(??, '{b}', ?)`, ['test', 1])
})
first solution changes the whole column cell and test will be only { b: 1 }
second solution doesn't work it give an error
function jsonb_set(json, unknown, unknown) does not exist
The expected result
is to manage to update only a certain key value in an object without changing the whole object.
PS
I also want to update an array that consists of objects like the above one for example.
[{a: "text", b: 0}, {c: "another-text", d: 0}]
if i use the code above in kenxjs it'll update the whole array to only {b: 1}
PS after searching a lot found that in order to make it work i need to set column type to jsonb, in order the above jsonb_set() to work
but now i'm facing another issue
how to update multiple keys using jsonb_set
knexDb('users').where({
email: email
})
.update({
test: knexDb.raw(`jsonb_set(??, '{b}', ?)`, ['test', 1]),
test: knexDb.raw(`jsonb_set(??, '{a}', ?)`, ['test', "another-text"]),
})
the first query key b is now not updating, in fact all updates don't work except the last query key a, so can some explain why ?
Your issue is that you're overwriting test. What you're passing into update is a JS object (docs). You cannot have multiple keys with identical values (docs). You'll have to do something like this where you make 1 long string with all your raw SQL as the value to test.
knexDb('users').where({
email: email
})
.update({
test: knexDb.raw(`
jsonb_set(??, '{a}', ?)
jsonb_set(??, '{b}', ?)
`,
['test', "another-text", 'test', 1])
})
Probably a better option exists - one that would be much more readable if you have to do this for several columns is something like what I have included below. In this example, the column containing the jsonb is called json.
const updateUser = async (email, a, b) => {
const user = await knexDb('users')
.where({ email })
.first();
user.json.a = a;
user.json.b = b;
const updatedUser = await knexDb('users')
.where({ email })
.update(user)
.returning('*');
return updatedUser;
}
Update/insert a single field in a JSON column:
knex('table')
.update( {
your_json_col: knex.jsonSet('your_json_col','$.field', 'new value')
})
.where(...)
Update/insert multiple fields
Option 1 (nested)
knex('table')
.update( {
your_json_col: knex.jsonSet(knex.jsonSet('your_json_col','$.field1', 'val1')
'$.field2', 'val2')
})
.where(...)
Option 2 (chained)
knex('table')
.update( {
your_json_col: knex.jsonSet('your_json_col','$.field1', 'val1')
})
.update( {
your_json_col: knex.jsonSet('your_json_col','$.field2', 'val2')
})
.where(...)
I am using Bookshelf JS as my ORM. I want to query for a special entity and update it one query (as if I execute INSERT INTO... WHERE...)
How can I do this without a raw query?
Here is how I do it right now:
async function updateSetting() {
let userSetting = await Setting.where({user: 1, key: 'foo'}).fetch()
await userSetting.save({value: {confirmed: true, order: 66}})
}
You could try this:
async function updateSetting() {
let userSetting = await Setting
.where({user: 1, key: 'foo'})
.save(
{value: {confirmed: true, order: 66}},
{method: 'update', patch: true}
)
}
To update a model without doing a fetch() you need to have the model's id_Attribute (usually just id) or to use a where() clause (as mentioned by #websoftwares)
Something just like:
new Setting({ id: 99 })
.save({ value: { confirmed: true, order: 66} },
{ patch: true })
Note in this case you do not need to specify the method because the presence of id implies you are updating an existing row.
I am attempting to create an instance and multiple related instances with a many to many relation using a junction table.
While creating the multiple related instances, I need to add a value to a property on the junction table as well. I don't know if it is my lack of knowledge of sequelize or promises that is causing my problem.
The code I am using is below. This code does add the items to the database, but I need to redirect after the operation has completed, which is not working.
Basically, I need to create a Recipe. Once that is created, I need to create Ingredients and relate them to that Recipe. The ingredients are stored in an array coming from a form on an HTML page. While relating the Ingredients, I need to add the ingredient_quantity to the RecipeIngredients table, which is the through part of the relationship (the junction table).
global.db.Recipe.belongsToMany(
global.db.Ingredient,
{
as: 'Ingredients',
through: global.db.RecipeIngredients,
foreignKey: 'recipe_id'
});
global.db.Ingredient.belongsToMany(
global.db.Recipe,
{
as: 'Recipes',
through: global.db.RecipeIngredients,
foreignKey: 'ingredient_id'
});
router.post('/new', ensureLoggedIn, bodyParser.json(), function (req, res) {
var recipeName = req.body.recipe_name;
var steps = req.body.steps;
var ingredients = req.body.ingredients;
var ingredientQty = {};
var currentIngredient;
var ingredientsToAdd = [];
db.Recipe.create({
recipe_name: recipeName,
directions: steps,
FamilyId: req.user.FamilyId,
CreatedBy: req.user._id
})
.then(function (recipe) {
for (var i = 0; i < ingredients.length; i++) {
currentIngredient = ingredients[i];
ingredientQty[currentIngredient.ingredient_name] =
currentIngredient.quantity;
db.Ingredient.findOrCreate({
where: {
ingredient_name: currentIngredient.ingredient_name,
FamilyId: req.user.FamilyId
}
})
.spread(function (ingredient, created) {
if (created) {
console.log("Added Ingredient to DB: " +
currentIngredient.ingredient_name);
}
ingredient.Recipes = {
ingredient_quantity:
ingredientQty[ingredient.ingredient_name]
};
ingredient.CreatedBy = req.user._id;
recipe.addIngredient(ingredient)
.then(function () {
console.log("Added Ingredient " + ingredient.ingredient_name
+ " to Recipe " + recipe.recipe_name);
});
})
}
})
.finally(function(recipe){
res.redirect('/recipes');
});
});
Any help would be greatly appreciated. I know that I am running into issues because of trying to use promises inside of a loop, I just don't know how else I can accomplish this.
Using sequelize, you can create objects along with its associated objects in one step, provided all objects that you're creating are new. This is also called nested creation. See this link and scroll down to section titled "Creating with associations"
Coming to your issue, you've a many-to-many relationship between Recipe and Ingredient, with RecipeIngredients being the join table.
Suppose you've a new Recipe object which you want to create, like:
var myRecipe = {
recipe_name: 'MyRecipe',
directions: 'Easy peasy',
FamilyId: 'someId',
CreatedBy: 'someUserId'
}
And an array of Ingredient objects, like:
var myRecipeIngredients = [
{ ingredient_name: 'ABC', FamilyId: 'someId'},
{ ingredient_name: 'DEF', FamilyId: 'someId'},
{ ingredient_name: 'GHI', FamilyId: 'someId'}]
// associate the 2 to create in 1 step
myRecipe.Ingredients = myRecipeIngredients;
Now, you can create myRecipe and its associated myRecipeIngredients in one step as shown below:
Recipe.create(myRecipe, {include: {model: Ingredient}})
.then(function(createdObjects){
res.json(createdObjects);
})
.catch(function(err){
next(err);
});
And that is all !!
Sequelize will create 1 row in Recipe, 3 rows in Ingredient and 3 rows in RecipeIngredients to associate them.
I was able to fix the problem that I was having. The answers here helped me come up with my solution.
I am posting the solution below in case anyone else runs into a similar issue. I created a variable to store the Promise from Recipe.create(), I used Promise.map to findOrCreate all of the ingredients from the form data. Because findOrCreate returns an array containing Promise and a boolean for if the item was created, I then had to get the actual ingredients out of the results of the Promise.map function. So I used the JavaScript array.map() function to get the first item from the arrays. And finally, use Promise.map again to add each Ingredient to the Recipe
var ingredients = req.body.ingredients,
recipeName = req.body.recipeName,
ingredientsQty = {}; // Used to map the ingredient and quantity for the
// relationship, because of the Junction Table
var recipe = models.Recipe.create({recipe_name: recipeName});
// Use Promise.map to findOrCreate all ingredients from the form data
Promise.map(ingredients, function(ing){
ingredientsQty[ing.ingredient_name] = ing.ingredient_quantity;
return models.Ingredient.findOrCreate({ where: { ingredient_name: ing.ingredient_name}});
})
// Use JavaScript's Array.prototype.map function to return the ingredient
// instance from the array returned by findOrCreate
.then(function(results){
return results.map(function(result){
return result[0];
});
})
// Return the promises for the new Recipe and Ingredients
.then(function(ingredientsInDB){
return Promise.all([recipe, ingredientsInDB]);
})
// Now I can use Promise.map again to create the relationship between the /
// Recipe and each Ingredient
.spread(function(addedRecipe, ingredientsToAdd){
recipe = addedRecipe;
return Promise.map(ingredientsToAdd, function(ingredientToAdd){
ingredientToAdd.RecipeIngredients = {
ingredient_quantity: ingredientsQty[ingredientToAdd.ingredient_name]
};
return recipe.addIngredient(ingredientToAdd);
});
})
// And here, everything is finished
.then(function(recipeWithIngredients){
res.end
});
I need to increment a column with 1 on some occasions, but the default value of that column is null and not zero. How do I handle this case using sequelize? What method could be utilized?
I could do by checking the column for null in one query and updating it accordingly in the second query using sequelize but I am looking for something better. Could I handle this one call?
I'll confess that I'm not terribly experienced with sequelize, but in general you'll want to utilize IFNULL. Here's what the raw query might look like:
UPDATE SomeTable
SET some_column = IFNULL(some_column, 0) + 1
WHERE <some predicate>
Going back to sequelize, I imagine you're trying to use .increment(), but judging from the related source, it doesn't look like it accepts anything that will do the trick for you.
Browsing the docs, it looks like you might be able to get away with something like this:
SomeModel.update({
some_column: sequelize.literal('IFNULL(some_column, 0) + 1')
}, {
where: {...}
});
If that doesn't work, you're probably stuck with a raw query.
First you need to find the model instance and update via itself, or update directly via Sequelize Static Model API.
Then you'll check whether the updated field got nullable value or not ? If fails then do the manual update as JMar propose above
await model.transaction({isolationLevel: ISOLATION_LEVELS.SERIALIZABLE}, async (tx) => {
const user = await model.User.findOne({
where: {
username: 'username',
},
rejectOnEmpty: true,
transaction: tx,
});
const updatedRecord = await user.increment(['field_tag'], {
transaction: tx,
});
if (!updatedRecord.field_tag) {
/** Manual update & Convert nullable value into Integer !*/
await model.User.update({
field_tag: Sequelize.literal('IFNULL(field_tag, 0) + 1')
}, {
where: {
username: 'username',
},
transaction: tx,
});
}
});