Readme.md

QueryBuilder

QueryBuilder is a TypeScript class that provides LINQ-like querying capabilities for collections. It allows you to perform common operations such as where, select, join, sum, average, min, max, and more on your data collections.

Installation

To use QueryBuilder in your project, you can install it via npm:

npm i ts-linq-builder

Usage

Here's how you can use QueryBuilder in your TypeScript project:

import QueryBuilder from "ts-linq-builder";

const users = [
    { id: 1, name: "John" },
    { id: 2, name: "Jane" },
];

const userDetails = [
    { id: 1, age: 30 },
    { id: 2, age: 20 },
];

const queryBuilder = new QueryBuilder(users);

queryBuilder
    .join(userDetails, (outer, inner) => outer.id === inner.id, (outer, inner) => {
        return {
            id: outer.id,
            name: outer.name,
            age: inner.age,
        };
    })
    .forEach(item => console.log(item));    

queryBuilder
    .where(item => item.id === 1)
    .select(item => item.name)
    .forEach(item => console.log(item));


console.log(queryBuilder.first());
console.log(queryBuilder.any());
console.log(queryBuilder.single());
console.log(queryBuilder.last());

Example Project

See more Example

Available Operations

QueryBuilder supports the following operations:

where(filter: FilterFunction<T> | Partial<T>): QueryBuilder<T>;
select<K>(selector: SelectorFunction<T, K>): K[];
orderBy(comparator: (a: T, b: T) => number): QueryBuilder<T>;
orderByDescending(comparator: (a: T, b: T) => number): QueryBuilder<T>;
groupBy<K extends string | number | symbol>(keySelector: (item: T) => K): Record<K, T[]>;
skip(count: number): QueryBuilder<T>;
take(count: number): QueryBuilder<T>;
distinct(): QueryBuilder<T>;
count(): number;
any(): boolean;
join<U, R>(
inner: U[],
condition: (outer: T, inner: U) => boolean,
resultSelector: (outer: T, inner: U) => R
): R[];
first(filter?: (item: T) => boolean): T | undefined;
single(filter?: (item: T) => boolean): T | undefined;
last(filter?: (item: T) => boolean): T | undefined;
sum(selector: (item: T) => number): number;
average(selector: (item: T) => number): number;
min(selector: (item: T) => number): number | undefined;
max(selector: (item: T) => number): number | undefined;
add(item: T): QueryBuilder<T>;
remove(item: T): QueryBuilder<T>;
clear(): QueryBuilder<T>;
toPromise(): Promise<T[]>;
toArrayAsync(): Promise<T[]>;
toArray(): T[];
toListAsync(): Promise<T[]>;
toList(): T[];
map<U>(selector: (item: T) => U): QueryBuilder<U> 
static from<T>(data: T[]): QueryBuilder<T>;
static empty<T>(): QueryBuilder<T>;

Contributing

Feel free to contribute to this project by opening issues or submitting pull requests. We welcome your suggestions and improvements.

License

This project is licensed under the MIT License.