IQueryAndOrBuilder<TModel>.AndWhereIsNotNull(string left) Method

.NET Standard 2.x

Adds the AND logical operator and a search condition to the WHERE clause; and uses IS NOT NULL operator to search for values that are not null.

Namespace: SnapObjects.Data

Assembly: SnapObjects.Data.dll

Syntax

  IQueryAndOrBuilder<TModel> AndWhereIsNotNull(string left);

Parameters

left System.String

A SQL expression on the left of the IS NOT NULL operator.

Returns

IQueryAndOrBuilder<TModel>

Returns anIQueryAndOrBuilder<TModel> object which can be used to add more search conditions to the current WHERE clause.

Examples

The following code example demonstrates how to use the AndWhereIsNotNull method to add an AND IS NOT NULL condition to the WHERE clause. In this example, the IS NOT NULL condition specifies that the HireDate value cannot be null.

using Appeon.ApiDoc.Models.School;
using SnapObjects.Data;
using System;
using System.Threading.Tasks;

namespace Appeon.ApiDoc.IQueryAndOrBuilderExamples
{
    public class AndWhereIsNotNullExample
    {
        private SchoolContext _context;
        
        public AndWhereIsNotNullExample(SchoolContext dataContext)
        {
            // Sets Data Context
            _context = dataContext;
        }

        public async Task<int> Example() 
        {
            // Get a QueryBuilder.
            var Builder = _context.SqlModelMapper.GetQueryBuilder<Person>();
            
            // Defines a WHERE condition that the column of EnrollmentDate is not empty.
            Builder.WhereIsNotNull("EnrollmentDate")
                   .AndWhereIsNotNull("HireDate");
            
            var result = (await Builder.LoadAsync()).FirstOrDefault();
            
            if (result != null) 
            {
                Console.WriteLine("PersonID:    {0}", result.PersonID);
                Console.WriteLine("FirstName:   {0}", result.FirstName);
                Console.WriteLine("LastName:    {0}", result.LastName);
                Console.WriteLine("HireDate:    {0}", result.HireDate);
                Console.WriteLine("EnrollmentDate:  {0}", result.EnrollmentDate);
                Console.WriteLine("Discriminator:   {0}", result.Discriminator);
                
                return result.PersonID;
            }
            else 
            {
                Console.WriteLine("Not found!");
                
                return 0;
            }
            
            /*This code example produces the following output:   
            
                PersonID:    3015
                FirstName:   Chen
                LastName:    Ward
                HireDate:    10/12/1997 12:00:00 AM
                EnrollmentDate:  1/1/2019 12:00:00 AM
                Discriminator:   Student
            */
        }
    }
}

Example Refer To

Model Class: Person

Applies to

.NET Standard

2.x