Tutorials

Previous versions' tutorials (obsolete)

This section contains the tutorials that we written for older versions of EasyQuery and most probably are obsolete now.

Table class

Table class represents one table in a [Korzh.EasyQuery.Db.DbModel](api-reference-4x/korzh-easyquery-db-namespace/dbmodel-class) object

Table class

Table class represents one table in a [Korzh.EasyQuery.Db.DbModel](api-reference-5x/korzh-easyquery-db-namespace/dbmodel-class) object

Table class

Table class represents one table in a [Korzh.EasyQuery.Db.DbModel](api-reference/korzh-easyquery-db/korzh-easyquery-db-namespace/dbmodel-class) object

Aggregate data

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

Tables and links page

Learn how to work with tables and links within your Data Model, change and edit them.

Query with table joins

An example of query which require to define a table join(s) in case of using SQL. It's much more simple with EasyQuery.

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:

Working with table aliases

In this article, we provide all the information needed to use aliases properly. There is an explanation, what for aliases are in the DME and an example of using it.

Data Model Editor

Simple query over one table

How to build a simple query with 1-2 conditions over one table (entity)

About Data Model Editor

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

User-friendly name for tables

Some tips for choosing right “entities” and their “attributes”

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)..

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.

Building data model dynamically by information from a DataTable

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

Navigate through data model entities and attributes

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

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

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.