ISqlJoinOnBuilder.On(string left, SqlBinaryOperator sqlOperator, ISqlBuilder sqlBuilder) Method

.NET Standard 2.x

Creates an ON clause and adds a search condition to it. 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

  ISqlJoinOnAndOr On(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.ISqlJoinOnAndOr

Returns the ISqlJoinOnAndOr object which can be used to add more search conditions to the current ON clause.

Examples

The following code example uses the On method to set Sets the condition to join one table with another.

using SnapObjects.Data;
using System;

namespace Appeon.ApiDoc.ISqlJoinOnBuilderExamples
{
    public class OnExample
    {
        private readonly SchoolContext _context;

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

        public void Example6()
        {
            var sqlQueryBuilder = new SqlQueryBuilder();

            // Sets a query to get the largest DepartmentID.
            var sqlBuilder = new SqlQueryBuilder();
            sqlBuilder.SelectRaw("max(DepartmentID)")
                .From("Department");

            // Gets DepartmentID values and Name values from the "Department" table, 
            // and the Title values from the "Course" table.
            // Sets the condition to join the "Department" and "Course" tables: 
            // Department.DepartmentID less than the largest DepartmentID returned from the query.                              
            sqlQueryBuilder
                .Select("Department.DepartmentID")
                .Select("Department.Name")
                .Select("Course.Title")
                .From("Department")
                .Join("Course")
                .On("Department.DepartmentID",
                    SqlBinaryOperator.LessThan, sqlBuilder);

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

            Console.WriteLine(sql);
            
            /*This code example produces the following output:           
              SELECT
                [Department].[DepartmentID],
                [Department].[Name],
                [Course].[Title]
              FROM [Department] JOIN [Course]
              ON [Department].[DepartmentID] < (SELECT
                                                    MAX([DepartmentID])
                                                FROM [Department])
            */
        }
    }
}

Applies to

.NET Standard

2.x