ISqlHavingBuilder.Having(string left, SqlBinaryOperator sqlOperator, ISqlParameter parameter) Method

.NET Standard 2.x

Creates a HAVING clause and adds a search condition to the HAVING clause. You can specify 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

  ISqlHavingAndOr Having(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

SnapObjects.Data.ISqlHavingAndOr

Returns the ISqlHavingAndOr object which can be used to add more search conditions to the current HAVING clause.

Examples

The following code example demonstrates how to use the Having method to specify the HAVING condition for groups.

using SnapObjects.Data;
using System;

namespace Appeon.ApiDoc.ISqlHavingBuilderExamples
{
    public class HavingExample
    {
        private readonly SchoolContext _context;

        public HavingExample(SchoolContext dataContext)
        {
            // Sets the data context.
            _context = dataContext;
        }

        public void Example2()
        {
            var sqlQueryBuilder = new SqlQueryBuilder();

            // Groups "StudentGrade" table by StudentID and CourseID, and gets the sum of Grade of each group.
            // Specifies the HAVING condition for group to: StudentID equal to the input parameter.
            // The value of input parameter is specified when SQL is executed.                   
            sqlQueryBuilder
                .Select("StudentID")
                .Select("sum(Grade)")
                .From("StudentGrade")
                .GroupBy("StudentID, CourseID")
                .Having("StudentID",
                           SqlBinaryOperator.Equals,
                           SqlBuilder.Parameter<int>("studentid"));

            // Converts to raw SQL for the database corresponding to the data context.                
            string sql = sqlQueryBuilder.ToSqlString(_context);

            Console.WriteLine(sql);

            // Executes the SQL and specifies "6" for the input parameter.
            var studentGrade = _context.SqlExecutor.Select<DynamicModel>(sql, 6);

            /*This code example produces the following output:           
              SELECT
                [StudentID],
                sum(Grade)
              FROM [StudentGrade]
              GROUP BY
                [StudentID],
                [CourseID]
                HAVING ([StudentID] = @studentid)
           */
        }
    }
}

Applies to

.NET Standard

2.x