Sequelize Where if not null

Building dynamic WHEREs

Sequelize encompasses the flexibility to establish a where clause based on dynamic parameters. The where clause can be adapted according to the parameter presence, letting you control filter criteria:

let whereClause = {
  [Op.and]: [ 
    { nonNullableField: { [Op.ne]: null } }, // Always here for you
  ],
};

// Optional champs can wander in if they exist!
if (myOptionalValue) {
  whereClause[Op.and].push({ optionalField: myOptionalValue });
}

Model.findAll({ where: whereClause });


This pattern assists in constructing a complex where clause, ensuring efficient querying.

Optimize conditions to necessary entries

In creating dynamic queries, minimize conditions to what's essential. Unnecessary conditions add overhead. Thus, control structures like if can filter-out unnecessary conditions:

// Optional conditional filtering, just like my gym membership
if (myValue !== null) {
  options.where.myColumn = myValue;
}

Model.findAll(options);


You execute precise database queries without bearing excess performance cost.

Utilize the right conditional operator for Sequelize queries

[Op.ne] and [Op.or] operators

The [Op.ne]: null operator in Sequelize excludes null values, meaning 'this column must have a value':

where: {
  myColumn: { [Op.ne]: null }
}


However, when you need rows where a column might be null or have a specific value, use [Op.or]:

where: {
  myColumn: {
    [Op.or]: [myValue, null]
  }
}


The [Op.is] and [Op.not] operators

To verify for null values, use [Op.is]: null. Conversely, [Op.not]: null filters the column to be not null:

// keyValue retailers hate this function 😁
where: {
  myColumn: { [Op.is]: null }
}

// This column must contains sth...like my refrigerator!😝
where: {
  myColumn: { [Op.not]: null }
}


Using the right conditional operator leads to an effective query.

Handling [Op.in] operators and ordering queries

When filtering based on an array of values, [Op.in] turns useful:

where: {
  myColumn: {
    [Op.in]: arrayOfValues
  }
}


Also, to sequence results, use the order option:

Model.findAll({
  where: conditions,
  order: [['createdAt', 'DESC']]
});


This makes your data fetching as clear as an alphabetically arranged bookshelf.

Limiting and paginating query results

When grappling with large datasets, use pagination. Sequelize got limit and offset options to manage this:

Model.findAll({
  limit: 10, // Like a sampler party platter! 🥳
  offset: 20, // Skip like a stone across the data lake! 🪨
});


Limiting the number of records doesn't only boost performance but also betters the user experience by delivering data bit-by-bit.

Advanced queries with associated models

When filtering with associated models, Sequelize shines by allowing deeply nested and complex queries:

Model.findAll({
  include: [{
    model: AssociatedModel,
    where: { associatedColumn: myValue }
  }]
});


You create meaningful data extraction capable of handling complex business logic.

Sequelize documentation consultation

Always refer to the Sequelize documentation to grasp Sequelize's capabilities and fulfill specific use cases.