How to generate C# Class from SQL Server Table

C# Class from SQL Database Table

There are multiple ways you can generate a C# class from your Database Table. We will be covering the following topics in today’s article.

• Generate Class with foreign key relation

• Generate Class with only entities

Generate Class with foreign key relations

For this we can simply use Entity Frameworks EDMX update feature which will generate our C# class from Database Tables. The output from EDMX will contain foreign key relations which we can see from the virtual interfaces like this - 

public partial class AssetItem
    {
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors")]
        public AssetItem()
        {
            this.AssetItemDepreciations = new HashSet<AssetItemDepreciation>();
            this.AssetTaxMappings = new HashSet<AssetTaxMapping>();
            this.AssetVatMappings = new HashSet<AssetVatMapping>();
            this.Assets = new HashSet<Asset>();
        }
    
        public int Id { get; set; }
        public int CategoryId { get; set; }
        public string ShortName { get; set; }
        public string Name { get; set; }
        public string PermittedOfficeLevel { get; set; }
        public Nullable<double> DefaultResidualValue { get; set; }
        public int Status { get; set; }
        public bool IsFixedStatus { get; set; }
        public string CreatedBy { get; set; }
        public System.DateTime CreatedOn { get; set; }
        public string UpdatedBy { get; set; }
        public Nullable<System.DateTime> UpdatedOn { get; set; }
    
        public virtual AssetCategory AssetCategory { get; set; }
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
        public virtual ICollection<AssetItemDepreciation> AssetItemDepreciations { get; set; }
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
        public virtual ICollection<AssetTaxMapping> AssetTaxMappings { get; set; }
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
        public virtual ICollection<AssetVatMapping> AssetVatMappings { get; set; }
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
        public virtual ICollection<Asset> Assets { get; set; }

This can be a little bit problamatic if we want a class so that we can use it in our POST method model. Because ASP.NET makes it a hassle when we want to use this complex class as a model. For that, we might need a work-around so that we can omit these.

Generate Class with only entities

If we only want to create the class with entities, no need for foreign key relations (which is managed by virtual interfaces in C#), we might need a work-around.

The following code snippet will guide to create a simple C# Class from the table.

declare @TableName sysname = 'TableName'
declare @Result varchar(max) = 'public class ' + @TableName + '
{'

select @Result = @Result + '
    public ' + ColumnType + NullableSign + ' ' + ColumnName + ' { get; set; }
'
from
(
    select 
        replace(col.name, ' ', '_') ColumnName,
        column_id ColumnId,
        case typ.name 
            when 'bigint' then 'long'
            when 'binary' then 'byte[]'
            when 'bit' then 'bool'
            when 'char' then 'string'
            when 'date' then 'DateTime'
            when 'datetime' then 'DateTime'
            when 'datetime2' then 'DateTime'
            when 'datetimeoffset' then 'DateTimeOffset'
            when 'decimal' then 'decimal'
            when 'float' then 'double'
            when 'image' then 'byte[]'
            when 'int' then 'int'
            when 'money' then 'decimal'
            when 'nchar' then 'string'
            when 'ntext' then 'string'
            when 'numeric' then 'decimal'
            when 'nvarchar' then 'string'
            when 'real' then 'float'
            when 'smalldatetime' then 'DateTime'
            when 'smallint' then 'short'
            when 'smallmoney' then 'decimal'
            when 'text' then 'string'
            when 'time' then 'TimeSpan'
            when 'timestamp' then 'long'
            when 'tinyint' then 'byte'
            when 'uniqueidentifier' then 'Guid'
            when 'varbinary' then 'byte[]'
            when 'varchar' then 'string'
            else 'UNKNOWN_' + typ.name
        end ColumnType,
        case 
            when col.is_nullable = 1 and typ.name in ('bigint', 'bit', 'date', 'datetime', 'datetime2', 'datetimeoffset', 'decimal', 'float', 'int', 'money', 'numeric', 'real', 'smalldatetime', 'smallint', 'smallmoney', 'time', 'tinyint', 'uniqueidentifier') 
            then '?' 
            else '' 
        end NullableSign
    from sys.columns col
        join sys.types typ on
            col.system_type_id = typ.system_type_id AND col.user_type_id = typ.user_type_id
    where object_id = object_id(@TableName)
) t
order by ColumnId

set @Result = @Result  + '
}'

print @Result

We just need to set @TableName to out TableName. For example, let's say we want to convert our Asset table to a C# class.

So we have put 'Asset' in our @TableName.

The output is as follows- 

public class Asset
{
    public long Id { get; set; }

    public string AssetId { get; set; }

    public int ItemTypeId { get; set; }

    public int ItemCategoryId { get; set; }

    public int AssetType { get; set; }

    public bool IsFixedAsset { get; set; }

    public int PurchaseBranchId { get; set; }

    public int CurrentBranchId { get; set; }

    public long PurchaseWorkingDate { get; set; }

    public int? SupplierId { get; set; }

    public int? Manufacturer { get; set; }

    public string Brand { get; set; }

    public string Model { get; set; }

    public string SerialNumber { get; set; }

    public string Specification { get; set; }

    public long? WarrantyExpireDate { get; set; }

    public double ResidualValue { get; set; }

    public int UsefulLife { get; set; }

    public long? ExpiryDate { get; set; }

    public string PurchaseOrderNumber { get; set; }

    public long? PurchaseOrderDate { get; set; }

    public string InvoiceNumber { get; set; }

    public long? InvoiceDate { get; set; }

    public string ChalanNo { get; set; }

    public long? ChalanDate { get; set; }

    public double BillingPrice { get; set; }

    public bool IsVatDeductible { get; set; }

    public double? VatAmount { get; set; }

    public double? TaxAmount { get; set; }

    public int PurchaseMethod { get; set; }

    public string BankAccount { get; set; }

    public string ChequeNo { get; set; }

    public long? ChequeDate { get; set; }

    public int LocationOfficeType { get; set; }

    public int LocationOfficeId { get; set; }

    public string LocationName { get; set; }

    public int? DepartmentId { get; set; }

    public int? AssignedEmployee { get; set; }

    public int? EntryBatchId { get; set; }

    public int? BatchQuantity { get; set; }

    public int Status { get; set; }

    public int? SubStatus { get; set; }

    public double? AccumulatedDepreciationAmount { get; set; }

    public long? LastDepreciationPeriod { get; set; }

    public double? WrittenDownValue { get; set; }

    public double? CurrentYearDepreciationAmount { get; set; }

    public long? LocationEntryDate { get; set; }

    public long? LocationExitDate { get; set; }

    public long? DisposalDate { get; set; }

    public long? LastStatusChangeSystemDate { get; set; }

    public long? LastStatusChangeBranchDate { get; set; }

    public string CreatedBy { get; set; }

    public DateTime CreatedOn { get; set; }

    public string UpdatedBy { get; set; }

    public DateTime? UpdatedOn { get; set; }

    public long? BranchWorkingDate { get; set; }

    public int? PreviousSubStatus { get; set; }

    public int? DocumentId { get; set; }

    public int? BranchAmmsId { get; set; }  

}

So, we have seen how qucikly we can convert our SQL Server Database Table into a C# Table.