IQueryWhereBuilder.Where(string left, SqlBinaryOperator sqlOperator, ISqlBuilder sqlBuilder) 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 subquery on the right.

Namespace: SnapObjects.Data

Assembly: SnapObjects.Data.dll

Syntax

  IQueryAndOrBuilder<TModel> Where(string left, SqlBinaryOperator sqlOperator, ISqlBuilder sqlBuilder);

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.

sqlBuilder SnapObjects.Data.ISqlBuilder

An ISqlBuilder object which represents a SQL subquery on the right of the operator.

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 that the column value must be within the result set of a SQL subquery.

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> Example6()
        {
            // Get a QueryBuilder.
            var Builder = _context.SqlModelMapper.GetQueryBuilder<Person>();
            
            // Defines a subquery.
            var sqlbuilder = new SqlQueryBuilder();
            sqlbuilder.Select("DepartmentID")
                .From("Department")
                .WhereValue("Name", "Economics");
                
            // 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 
            // subquery on the right.
            Builder.Where("PersonID", SqlBinaryOperator.Equals, sqlbuilder);
            
            var result = (await Builder.LoadAsync()).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:    4
                FirstName:   Fadi
                LastName:    Fakhouri
                HireDate:    8/6/2002 12:00:00 AM
                Discriminator:   Instructor
            */
        }
    }
}

Example Refer To

Model Class: Person

Applies to

.NET Standard

2.x