DwTableBlobAttribute Class

.NET Standard 2.x

Specifies the BLOB column.

Namespace: DWNet.Data

Assembly: DWNet.Data.dll

Syntax

    [AttributeUsage(AttributeTargets.Property, AllowMultiple = false)]
    public class DwTableBlobAttribute : PropertySaveAttribute

Constructors

Name	Description
DwTableBlobAttribute(string table, string column, string keyClause, DwFileType fileType):base(SaveStrategy.Ignore)	Initializes a new instance of the DwTableBlobAttribute class.

Properties

Name	Return Type	Description
Table	string	Gets the table name.
Column	string	Gets the column name.
KeyClause	string	Gets the query condition.
FileType	DwFileType	Gets the file type.

Examples

The following code example demonstrates how to use the Model DwTableBlob attribute.

Model: D_TableBlobRetrieve

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;
using System.Runtime.Serialization;
using SnapObjects.Data;
using DWNet.Data;
using Newtonsoft.Json;
using System.Collections;

namespace Appeon.ApiDoc.Models.School
{
    [DataWindow("dw_2", DwStyle.Default)]
    [Table("testblob", Schema = "appeon")]
    #region DwSelectAttribute  
    [DwSelect("PBSELECT( VERSION(400) TABLE(NAME=\"appeon.testblob\" ) @(_COLUMNS_PLACEHOLDER_) WHERE(    EXP1 =\"testblob.uid\"   OP =\"=\"    EXP2 =\":uid\" ) ) ARG(NAME = \"uid\" TYPE = number)")]
    #endregion
    [DwParameter("uid", typeof(double?))]
    [DwKeyModificationStrategy(UpdateSqlStrategy.DeleteThenInsert)]
    [UpdateWhereStrategy(UpdateWhereStrategy.KeyAndConcurrencyCheckColumns)]
    public class D_TableBlobRetrieve
    {
        [Key]
        [DwColumn("appeon.testblob", "uid")]
        public int Uid { get; set; }
        
        [JsonIgnore]
        [IgnoreDataMember]
        [PropertySave(SaveStrategy.Save)]
        [DwTableBlob("appeon.testblob", "tableblobimg", "uid = :uid", DwFileType.Img)]
        public byte[] Blob_1 { get; set; }
        
    }
    
}

Example Method:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Appeon.ApiDoc.Models.School;
using DWNet.Data;

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

        public void Example() 
        {
            // Instantiates a DataStore object with datawindow: D_TableBlobRetrieve.
            var dataStore = new DataStore<D_TableBlobRetrieve>(_context);
            
            var row = dataStore.Retrieve(1);
            
            // Gets a Model object.
            var model = dataStore.GetModel(0);
            
            // Show the value of Model object.
            Console.WriteLine("Row: {0}", row);
            Console.WriteLine("dataStore.Blob: {0}",  model.Blob_1);
            
            /* This code example produces the following output:
            
                Row: 1
                dataStore.Blob_1: System.Byte[]
            */
        }
    }
}