SqlBuilder.EmbeddedHaving(string left, ISqlParameter parameter) Method

.NET Standard 2.x

Creates an ISqlHavingCondition object which represents a search condition that can be used (enclosed in parentheses) when building the HAVING clause. Specifies a SQL expression on the left of the operator and a SQL parameter on the right of the operator. The operator is '='.

Namespace: SnapObjects.Data

Assembly: SnapObjects.Data.dll

Syntax

  public static ISqlHavingCondition EmbeddedHaving(string left, ISqlParameter parameter);

Parameters

left System.String

A SQL expression on the left of the operator.

parameter SnapObjects.Data.ISqlParameter

An ISqlParameter object which represents a SQL parameter.

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

Returns

SnapObjects.Data.ISqlHavingCondition

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

Remarks

The newly created search condition is enclosed in parentheses. If the returned ISqlHavingCondition object is used to add another search condition, both of these search conditions will be enclosed in the same pair of parentheses.

Examples

The following code example demonstrates how to use the EmbeddedHaving(string left, ISqlParam parameter) method to specify the HAVING condition.

using SnapObjects.Data;
using System;

namespace Appeon.ApiDoc.SqlBuilderExamples
{
    public class EmbeddedHavingExample
    {
        private SchoolContext _context;

        public EmbeddedHavingExample(SchoolContext dataContext)
        {
            // Sets Data Context.
            _context = dataContext;
        }

        public void Example3()
        {
            var sqlQueryBuilder = new SqlQueryBuilder();

            // Defines an EmbeddedHaving condition: StudentID = @studentid
            var having = SqlBuilder.EmbeddedHaving("StudentID",
                SqlBuilder.Parameter<int>("studentid"));

            // Builds a SQL statement to retrieve StudentID and sum(Grade) from the "StudentGrade" table, and
            // group records by StudentID and CourseID which meet the condition: StudentID = @studentid.            
            var havingQuery = sqlQueryBuilder
                .Select("StudentID")
                .Select("sum(Grade)")
                .From("StudentGrade")
                .GroupBy("StudentID, CourseID")
                .Having(having);

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

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

Applies to

.NET Standard

2.x