ISqlExecutor.SelectOneAsync<TModel>(string sqlText, params object[] parameters) Method

.NET Standard 2.x

Asynchronously executes the SQL SELECT statement and returns the first row in the result set. All other rows are ignored.

Namespace: SnapObjects.Data

Assembly: SnapObjects.Data.dll

Syntax

public Task<TModel> SelectOneAsync<TModel>(string sqlText, params object[] parameters);

Type Parameters

TModel

The datatype of the model object which represents the data row in the result set.

You can also specify DynamicModel to TModel if you do not want to define a custom model class.

Parameters

sqlText System.String

A raw SQL statement which contains the parameter placeholders.

The proper syntax of a parameter placeholder is specific to the data source (e.g., @newFirstName for SQL Server). To make a parameterized SQL ( e.g., update Person set FirstName = @newFirstName where PersonId = 1), these placeholders are filled in with the actual parameter values when the SQL statement is executed.

parameters System.Object[]

(Optional) One or more ParamValue objects which contain the values corresponding to the SQL parameter identifier names.

You can also pass the arguments directly in the order in which each parameter identifier name appears in sqlText for the first time, without using the ParamValue object.

Returns

Task<TModel>

Returns a task that represents the asynchronous operation.

Remarks

You can use parameter placeholders in the raw SQL Statement. It is recommended to use the syntax for parameter placeholders that is specific to the data source. e.g., uses @parametername for SQL Server and uses :parametername for Oracle.

Examples

The following code example demonstrates how to execute the SQL statement and put the first row of the result set to a model object.

using System;
using System.Threading;
using System.Threading.Tasks;
using SnapObjects.Data;

namespace Appeon.ApiDoc.ISqlExecutorExamples
{
    public class SelectOneAsyncExample
    {
        private readonly SchoolContext _context;
        
        public SelectOneAsyncExample(SchoolContext dataContext)
        {
            // Sets the data context
            _context = dataContext;
        }

        public async void Example1()
        {
            // Defines the SQL SELECT statement.
            var sql = @"select CourseID, Title from Course";
            
            // Asynchronously Executes the SQL statement and gets the first row of
            // the result set.
            DynamicModel result = await _context.SqlExecutor.SelectOneAsync<DynamicModel>(sql);
            
            Console.WriteLine("CourseID: {0},Title: {1}.", result.GetValue<int>("CourseID"),
                                                           result.GetValue<string>("Title"));
            
            /*This code produces the following output:
            
                CourseID: 1045,Title: New Course.
            */
        }
    }
}

Applies to

.NET Standard

2.x