Convert C# Class to SQL table

Question

The only references I can find is someone suggesting to use Entity Framework to do this, but I don't have or use Entity Framework. The only other thing on this subject is going from SQL table to C# class, which is the opposite of what I want.

This doesn't have to be TSQL/MSSQL (2014) Compatible but that's my DBMS.

The C# class is just a POCO. I think I heard you could take the class and somehow convert it a DataTable and then using SqlBulkCopy have it create a table from the DataTable.

This is what I am currently using it uses a SELECT INTO and casting a null to a sqlType to make nullable columns. As you can see it's quite raw but gets the job done mostly - I am looking for less error prone methods.

        var columnNames = GetColumnsToBeUpdated<T>().ToList();
        var columnTypes = GetColumnsTypesToBeUpdated<T>().ToList();


        var selects = columnNames.Select((t, i) => $"CAST(NULL as {columnTypes[i]}) AS [{t}]");

        var createsql = $@"
            SELECT {string.Join(", ", selects)}
            INTO SDE.[{tableName}]";

        using (var connection = new SqlConnection(_sdeConnectionString))
        {
            EsriServer.ExecuteNonQuery(connection, $"IF OBJECT_ID(N'SDE.[{tableName}]', N'U') IS NOT NULL " +
                                                   $"DROP TABLE SDE.[{tableName}]", null);
            EsriServer.ExecuteNonQuery(connection, createsql, null);
            EsriServer.ExecuteNonQuery(connection, $"TRUNCATE TABLE SDE.[{tableName}]", null);
        }

    private static string GetSqlDataType(Type type)
    {
        var name = type.Name;
        if (type.IsGenericType && type.GetGenericTypeDefinition() == typeof(Nullable<>))
        {
            name = type.GetGenericArguments()[0].Name;
        }

        switch (name)
        {
            case "Guid":
                return "uniqueidentifier";
            case "Boolean":
                return "bit";
            case "Byte":
                return "tinyint";
            case "Int16":
                return "smallint";
            case "Int32":
                return "int";
            case "Int64":
                return "bigint";
            case "Decimal":
                return "decimal(38,25)";
            case "Single":
                return "real";
            case "Double":
                return "float";
            case "DateTime":
                return "datetime";
            case "String":
            case "Char[]":
                return "nvarchar(max)";
            case "Char":
                return "nvarchar(1)";
            case "Byte[]":
                return "varbinary";
            case "Object":
                return "sql_variant";
            default:
                throw new ArgumentOutOfRangeException();
        }
    }

    private static IEnumerable<string> GetColumnsToBeUpdated<T>() where T : class, new()
    {
        var typeT = new T();
        var ps = typeT.GetType().GetProperties();
        var propertyNames = ps.Select(p => p.Name);

        return propertyNames.Except(GetColumnsToBeIgnored<T>());
    }

    private static IEnumerable<string> GetColumnsTypesToBeUpdated<T>() where T : class, new()
    {
        var typeT = new T();
        var ps = typeT.GetType().GetProperties();
        return ps.Select(p => p.PropertyType).Select(GetSqlDataType).ToList();
    }

If this can't be done accurately or requires major code then I am pretty fine with an application or online server that lets me paste in a simple C# class and get back a create table statement.

Answer 1

You can convert the C# class to Json and then convert the Json to Sql.

Convert C# class to Json:

• Serialize the C# class to JSON using Json.NET.
• Convert online at csharp2json.io.

Convert Json to SQL online:

• www.jsonutils.com
• convertjson.com/json-to-sql.htm
• sqlify.io/convert