IQueryWhereBuilder.Where(string left, SqlBinaryOperator sqlOperator, ISqlParameter parameter) Method

.NET Standard 2.x

Creates a WHERE clause, and adds a search condition to the WHERE clause. Specifies a SQL expression on the left of the operator and a SQL parameter on the right of the operator.

Namespace: SnapObjects.Data

Assembly: SnapObjects.Data.dll

Syntax

  IQueryAndOrBuilder<TModel> Where(string left, SqlBinaryOperator sqlOperator, ISqlParameter parameter);

Parameters

left System.String

A SQL expression on the left of the operator.

SqlBinaryOperator SnapObjects.Data.SqlBinaryOperator

An enumeration value of SqlBinaryOperator, which is the operator to test the two expressions on the left and right.

parameter SnapObjects.Data.ISqlParameter

An ISqlParameter object which represents a SQL parameter on the right of the operator.

It can be created by calling the SqlBuilder.Parameter method.

Returns

IQueryAndOrBuilder<TModel>

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

Examples

The following code example uses the Where method to specify the column value to equal to an input parameter.

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

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

        public async Task<int> Example4()
        {
            // Get a QueryBuilder.
            var Builder = _context.SqlModelMapper.GetQueryBuilder<Person>();
            
            // Creates a WHERE clause, and adds a search condition to the WHERE clause.
            // Specifies a SQL expression on the left of the operator and a SQL 
            // parameter on the right of the operator.
            Builder.Where("PersonID", SqlBinaryOperator.Equals, SqlBuilder.Parameter<int>("id"));
            
            var result = (await Builder.LoadAsync(1)).ToList();
            
            foreach (var person in result)
            {
                Console.WriteLine("PersonID:    {0}", person.PersonID);
                Console.WriteLine("FirstName:   {0}", person.FirstName);
                Console.WriteLine("LastName:    {0}", person.LastName);
                Console.WriteLine("HireDate:    {0}", person.HireDate);
                Console.WriteLine("Discriminator:   {0}", person.Discriminator);
            }
            
            return result.Count;
            
            /*This code produces the following output:
            
                PersonID:    1
                FirstName:   Kim
                LastName:    Abercrombie
                HireDate:    3/11/1995 12:00:00 AM
                Discriminator:   Instructor
            */
        }
    }
}

Example Refer To

Model Class: Person

Applies to

.NET Standard

2.x