How to Implement Dynamic Filters in TypeORM with PostgreSQL

Learn how to create flexible search filters with multiple parameters using TypeORM and PostgreSQL's query builder for effective data retrieval.
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This video is based on the question https://stackoverflow.com/q/64023564/ asked by the user 'Baksha2008' ( https://stackoverflow.com/u/11566998/ ) and on the answer https://stackoverflow.com/a/64027094/ provided by the user 'Art Olshansky' ( https://stackoverflow.com/u/8368358/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

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How to Implement Dynamic Filters in TypeORM with PostgreSQL: A Step-by-Step Guide

Filtering data based on multiple criteria is a common requirement in web applications. Whether it’s searching for users by name, city, age, or skills, being able to efficiently filter data can significantly enhance user experience. In this guide, we’ll explore how to implement multiple parameter filters using TypeORM in conjunction with PostgreSQL.

The Problem

Imagine that you have a database of users and you want to allow your users to search through it with various parameters. The existing implementation presented some challenges, particularly when trying to include a more comprehensive filtering logic involving multiple fields.

Your initial code snippet attempted to create a search data object using the TypeORM’s findAndCount method, but you faced limitations when trying to leverage advanced SQL conditions like ILIKE for case-insensitive matching.

The Solution

Instead of using the default repository methods, you can make use of TypeORM's powerful Query Builder. The Query Builder allows you to construct SQL queries programmatically, giving you more control over the final query.

Setting Up Your Query Builder

First, start by extracting the parameters you want to filter by:

[[See Video to Reveal this Text or Code Snippet]]

Adding Dynamic Conditions

Depending on the filtering criteria provided, you can add conditions to the query builder as follows:

First Name Filter
If a firstName is provided, add a LIKE condition for partial matching in your query:

[[See Video to Reveal this Text or Code Snippet]]

Last Name Filter
Similarly, for last names:

[[See Video to Reveal this Text or Code Snippet]]

Company Name Filter
For exact matching on company names, you can do:

[[See Video to Reveal this Text or Code Snippet]]

Location Filter
And for filtering by location:

[[See Video to Reveal this Text or Code Snippet]]

Executing the Query

After defining all your conditions, run the query to get the results:

[[See Video to Reveal this Text or Code Snippet]]

This will retrieve both the filtered users and the count of how many records matched the criteria.

Full Code Example

Here’s how the entire implementation might look:

[[See Video to Reveal this Text or Code Snippet]]

Conclusion

Using the Query Builder in TypeORM can unlock a variety of advanced querying capabilities, including dynamically filtering your data based on multiple parameters. This approach not only provides more power and flexibility but also enhances performance in retrieving datasets from your database.

Feel free to adapt and expand upon the provided example based on your specific requirements. Happy coding!