How to setup SQL LIST value editor in WinForms app

Step-by-step instruction how to setup SQL LIST value editor.

Value Editors

Here you can find the full list of editors and choose any you need in your work with Data Model:

Setup custom value editor — WinForms

Here you can find all steps you need to perfom

Korzh.EasyQuery.WinForms

EasyQuery Windows Forms controls

Data Model Editor

Introduction to value editors

For example, value editor allows you to define a list of available values - so your users will be able to select the value from a drop-down list. "Custom list" value editor raises an event which can be processed either on the client-side or on the server. All other editions of EasyQuery (WinForms, WebForms, WPF or Silverlight) has ListRequest event in QueryPanel control which is raised when a user adds an attribute (or operator) with Custom List or SQL list value editor assigned to that attribute/operator. Here we show how you can filter the returned list according to the value specified for some other attribute. If such condition is defined - we get the value (country code) from it and use that value as a filter for the list of regions.

About Data Model Editor

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

Korzh.EasyQuery.WinForms namespace

Korzh.EasyQuery.WinForms.ModelEditor

EasyQuery Model Editor controls for Windows Forms

Dynamic populating of value lists in WinForms or WPF editions

Example of how to solve this problem

Common SQL queries

Processing custom value editors in EasyQuery JS

Here you can find tips how to value editor setup and how to value editor widget

Replace "value" element in QueryPanel's conditions — WinForms

Here is a step-by-step description what you need to achieve this goal

Upgrading to 5.x: WinForms and WPF projects

This tutorial describes how to modify your old Windows Forms or WPF project with EasyQuery 3.x to upgrade to EasyQuery version 5.2.0 (or higher). Please note. Version 5.2.0 of EasyQuery works only on .NET Framework 4.6.1 or higher. So, if your project targets a lower version of .NET Framework - you will need to update Target Framework for your project first (right-click on the project in Solution

Processing custom value editors in EasyQuery JS

First, of you will need to assign a custom (user-defined) value editor for some attribute or operator in your data model. You have to ways to do it: Run Data Model Editor (DME). Select an entity attribute which you want to assign custom value editor to. You can add a custom editor to any entity attribute in your model at run-time. Here is an example of very simple value editor in TypeScript.

Korzh.EasyQuery.WinForms.ModelEditor namespace

Customizing common SQL clauses

This article is about settings for adding different options to the whole query (like DISTINCT, LIMIT, etc)

Dynamically populate value lists by information from other conditions

Suppose we have a database with Customer entity which has Country and City attributes. For both these attributes we define the value editors which return the lists of available values (countries and cities correspondingly). Now let's imagine the user adds a condition with the Country attribute e.g. Hera the steps needed to implement such a functionality: Define a value editor for the City attribute as SQL LIST with Cities.@{{Customer.Country}} list name (here Customer.Country is the ID of the Country attribute in the Customer entity). Let's name it "CitesSqlValueList") and then in a value list resolver modify its SQL according the currently selected country and get the list of values using GetValueListAsync method of EasyQueryManager class: What's happening here.

Customizing SQL query formats

Detailed instruction with various examples of how to operate with different query formats.

Add query builder page from our MVC sample project in your own app

This article described how to set up an advanced search page in your web-application using EqMvcDemoDB project as a template.