ISqlBuilderBase.ValidateAsync(DataContext context, bool throwError, CancellationToken cancellationToken = default) Method

.NET Standard 2.x

Asynchronously validates the raw SQL string for the specified database generated by the current sqlbuilder.

Namespace: SnapObjects.Data

Assembly: SnapObjects.Data.dll

Syntax

Task<bool> ValidateAsync(DataContext context, bool throwError, CancellationToken cancellationToken = default);

Parameters

context SnapObjects.Data.DataContext

A DataContext object which contains the database connection information.

throwError System.Boolean

Optional.

True (default ) -- to throw an exception if the raw SQL is not valid in the specified database;

False -- Not to throw an exception if the raw SQL is not valid in the specified database.

cancellationToken CancellationToken

(Optional) A cancellation token that can be used by other objects or threads to receive notice of cancellation.

Returns

Task<bool>

Returns a task that represents the asynchronous operation.

Examples

The following code example demonstrates how to Asynchronous validate a SqlQueryBuilder object. It uses a CancellationTokenSource type parameter to make this operation cancelable.

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

namespace Appeon.ApiDoc.ISqlBuilderBaseExamples
{
    public class ValidateAsyncExample
    {
        private SchoolContext _context;
        
        public ValidateAsyncExample(SchoolContext dataContext)
        {
            // Sets Data Context
            _context = dataContext;
        }

        public async Task<bool> Example2(CancellationTokenSource cts)
        {
            // Builds a SQL statement.
            var sqlBuilder = new SqlQueryBuilder();
            sqlBuilder.Select("name")
                    .From("Department")
                    .WhereValue("DepartmentId", 1);
                    
            bool valid = false;
            
            try
            {
                // Asynchronous validates the SQL statement in database. 
                // If a task has been cancelled, the call to the ISqlModelMapper.LoadAllAsync 
                // method throws an OperationCanceledException.
                valid = await sqlBuilder.ValidateAsync(_context, throwError: true, cts.Token);
                
                Console.WriteLine("Validation Result (second time): {0}", valid);
            }
            catch (OperationCanceledException e) 
            {
                // The operation was cancelled before completion.
                Console.WriteLine(e.Message);
            }
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
            }
            finally 
            {
                cts.Dispose();
            }
            
            return valid;
            
            /*This code produces the following output:
            
                A task was canceled.
            */
        }
    }
}

Applies to

.NET Standard

2.x