SqlBuilder.Select(ISqlBuilder sqlBuilder, string alias = "") Method

.NET Standard 2.x

Creates an ISqlQueryBuilder object for building a SQL SELECT statement and adds a column of SQL subquery (specified by an ISqlBuilder object) to the select list of the SELECT clause. You can specify an alias for this column.

Namespace: SnapObjects.Data

Assembly: SnapObjects.Data.dll

Syntax

 public static ISqlQueryBuilder Select(ISqlBuilder sqlBuilder, string alias = "");

Parameters

sqlBuilder SnapObjects.Data.ISqlBuilder

An ISqlBuilder object which represents a SQL subquery.

alias System.String

(Optional) The alias of the column.

The default value is an empty string.

Returns

SnapObjects.Data.ISqlQueryBuilder

Returns a newly created ISqlQueryBuilder object which can be used to build the SQL SELECT statement.

Examples

The following code example demonstrates how to use the Select(ISqlBuilder sqlBuilder, string alias = "") method. The column is selected using a subquery and is given an alias.

using SnapObjects.Data;
using System;

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

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

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

            // Defines the subquery and sets the WHERE condition to associate with the tables.
            sqlquerybuilder.Select("name")
                .From("Department")
                .Where("departmentid", "c.departmentid");
            
            // Retrieves title values from the "course" table and name values from the "Department" table.
            // Specifies "name" as the alias for the name column selected by the subquery.
            var query = SqlBuilder
                .Select(sqlquerybuilder, "name")
                .Select("title")
                .From("course", "c");

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

            Console.WriteLine(sql);
            
            /*This code example produces the following output:           

            SELECT
            (SELECT
            [name]
            FROM [Department]
            WHERE ([departmentid] = [c].[departmentid])) AS [name],
            [title]
            FROM [course] AS [c]
            */
        }
    }
}

Applies to

.NET Standard

2.x