Using Where Conditions

In many applications, there arises a need to construct dynamic queries to filter data from a database. The Where class provides a powerful tool for composing such queries. Let's walk through how to use it effectively.

1. Initializing Where

First, import the Where class into your file:

import { Where } from "@soapjs/soap";

Then, instantiate a new Where object:

const where = new Where();

2. Adding Conditions

You can add conditions to the Where object using various methods like isEq, isNotEq, isLt, isLte, isGt, isGte, isIn, isNotIn, and like.

where.valueOf("name").isEq("John");
where.valueOf("age").isGt(25).and.valueOf("status").isEq("active");

3. Combining Conditions

You can combine conditions using logical operators like and and or.

where.valueOf("age").isGt(25).or.valueOf("age").isLt(18);
where.valueOf("status").isEq("active").and.brackets((w) => {
    w.valueOf("age").isGt(25).or.valueOf("age").isLt(18);
});

4. Building the Condition

Once you've added all the desired conditions, you can build the final condition using the build method:

const condition = where.build();

Example Usage

Let's consider a scenario where we want to find all active customers aged between 18 and 30.

const where = new Where()
    .valueOf("status").isEq("active")
    .and.valueOf("age").isGte(18).and.valueOf("age").isLte(30);

const repository = ioc.get<CustomerRepository>(CustomerRepository.Token);
const params = new FindParams(100, 0, null, where);
const result = await repository.find(params);

Conclusion

The Where class offers a flexible and intuitive way to compose dynamic queries in TypeScript. By leveraging its methods for adding and combining conditions, you can easily construct complex filters for querying your data.