Mandarine Query Language

Mandarine Query Language (MQL) is a sub-module of Mandarine's repositories. Although, MQL is considered an autonomous submodule.

Understanding of Mandarine's ORM concepts is required for this article

Main

Mandarine Query Language (MQL) serves as a helper to write queries. The main objective of MQL is to avoid the writing of SQL queries in your application's layer, and keep everything in a programatic environment. This is because, Mandarine.TS aims to respect SOLID principles & follow MVC patterns as well as making your code as simple and readable as possible.

Note that MQL is written inside repositories

The lexical processor

MQL makes use of a lexical processor that will transform the names of your repositories' methods in SQL & processable queries.

findByAirlineAndPassengerName(airline: string, passengerName: string)

Will be transformed into

SELECT * FROM MyTable WHERE airline = $1 AND passengerName = $2

# MyTable = Table of your model related to your repository 
# $1 = airline parameter
# $2 = passengerName parameter

MQL Operators

Operators are keywords that will tell the lexical processor what type of operation is being requested at a SQL level.

Currently, MQL only supports the operators

• AND

• OR

• IsNotNull

• IsNull

• IsNotEmpty

• IsEmpty

• StartingWith

• EndsWith

• Like

Although, more operators are planned to be released. Click here for more information.

Definers

Definers are keywords that will shape your final SQL query. Definers are used for the lexical processor to identify what type of query is being or will be built.

General definers

• findAll: Select all rows

• deleteAll: Delete all rows in entity

• countAll: Count all rows in entity

• findBy...: Creates & executes a select query

• countBy...: Creates & executes a select count query

• existsBy...: Creates & executes a verification statement

• deleteBy...: Creates & executes a delete query

"Save" definer

In order to add (or update) information to your entity in your database, MQL allows you to do so by using save (Click here to see declaration)

• save is part of a native method of a mandarine repository.

• save takes one argument which will be a object of your repository's model with the data to be inserted

Naming conventions

1. Do use camel case

2. Do not use underscores, or other characters that may affect readability.

3. The names of your columns must match the name of your parameter in your repository method. Otherwise, query execution will fail.