Data Model

In short (and by its name), data model - is a model (representation) of some data stored in your database. It solves two major problems: Presents the data to the end user in a more friendly and familiar way. Contains some meta information that helps EasyQuery components to build query statements in SQL or other query languages. Any data model contains the following main sections:

Data Model Editor

Build query by code on the client-side

Here you can find an example of JavaScript code with explanation how to add columns to a current query on client-side.

About Data Model Editor

Here you can find detailed information about this instrument and guideline, how to use it to perform all needed tasks.

Building data model dynamically by DB meta-information

It's easier to fill your model right in the code directly from your database, using meta-information

Building data model dynamically by information from a DataTable

Example of how to build data model by certain information from DataTable

Creating data model dynamically with code

-Data Model- object is an essential part of EasyQuery framework. However, sometimes you need to add some entities, entity attributes or operators to the existing model or to fill it from scratch using DB metadata information got from another source. In these cases, you can use EasyQuery API to build the model dynamically. Finally, we add entities and entity attributes. Here is an example of creatin a small data model: two tables (Customers and Orders) with one link between them, 2 entities (Customer and Order correpondingly) and a few attributes in each entity.

Building data model dynamically using code (version 3.x)

Here you can find all steps you need to perform

Aggregate data

From this article you will see how to aggregate (count, sum, etc.) data in your queries.

Working with several data models

All EasyQuery demos works with one data model (and one database which corresponds to that model). Here we are going to describe how to add a selector that switches between two data models on your view/page and then how to setup a custom "model loader" to handle GetModel requests propertly. To make it possible to switch between these two models we need some selector element on our page. The only problem here - is to switch the database connection accordingly the the switches between the models. Now when the user selects an item in our model selector element on the client-side - our server-side code automatically loads the selected model and connects to a proper database (when necessary)..

Adding columns and conditions with code

Example of code for adding columns and conditions

Possible ways of data model creation and loading

EasyQuery components need a [data model](/$aid/03bc06b0-83ec-4040-97ef-a50ca004177f) (a user-friendly representation of your DB) for their work. There are several different ways to create the model and load it on your project's startup. This article will describe all of them in detail.

Navigate through data model entities and attributes

A code snippet which demonstrates how to run through data model entities and attributes

Adding a new operator to your data model

Here you can find all information about how to add a new operator to your data model either using Data Model Editor (DME) or with a code

Create a query with sub-query by code

Example with code

Working with data models in EasyQuery

This article will guide you through all issues about working with data models in EasyQuery library. How to load it from the DbContext or from your DB connection, or now to create a new one using Data Model Editor.

Copying the EasyQuery's code from a sample to your project

If you have already modified one of our sample projects to make it work with your DB, the next step will be to copy the EasyQuery's code to your own solution. This article describes how to do it.

Building dynamic queries with EasyQuery and Entity Framework

Here we describe how EasyQuery helps to implement a query building UI for creating custom, dynamic queries in .NET projects which use Entity Framework (6.x)

Create virtual (calculated) attribute in you model

Virtual attributes: what are they for and how to add one

Managing data formats

This article shows how to implement some particular tasks with your query