SqlBuilder.EmbeddedHaving(string left, SqlBinaryOperator sqlOperator, ISqlBuilder sqlBuilder) 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 subquery on the right.

Namespace: SnapObjects.Data

Assembly: SnapObjects.Data.dll

Syntax

 public static ISqlHavingCondition EmbeddedHaving(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

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,SqlOperator sqlOperator,ISqlBuilder sqlBuilder) 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 Example6()
        {
            var sqlQueryBuilder = new SqlQueryBuilder();

            // Gets the smallest Course ID and uses it as a parameter for the HAVING condition.
            var sqlBuilder = new SqlQueryBuilder();
            sqlBuilder.SelectRaw("min(CourseID)")
                .From("Course");

            // Defines an EmbeddedHaving condition.
            var having = SqlBuilder
                .EmbeddedHaving("CourseID", SqlBinaryOperator.GreaterThan, sqlBuilder);


            // 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: CourseID greater than the result set of the sqlBuilder subquery.
            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 ( [CourseID] > (SELECT
            MIN([CourseID])
            FROM [Course]))
            */
        }
    }
}

Applies to

.NET Standard

2.x