LibraryWeb/App_Code/SQLExtensions.cs

using Microsoft.Data.SqlClient;
using System.Data.SqlTypes;

namespace Library;

public static class SQLExtensions
{
	public static string? String( this SqlDataReader reader , string column_id )
	{
		int column_index = reader.FindColumn( column_id );
		if ( column_index < 0 )
			return null;

		return reader.String( column_index );
	}

	public static string? String( this SqlDataReader reader , int column_index )
	{
		if ( reader.IsDBNull( column_index ) )
			return null;

		string? o = reader[ column_index ].ToString( );
		if ( o == null )
			return null;

		return o!;
	}

	public static string StringSafe( this SqlDataReader reader , string column_id )
	{
		int column_index = reader.FindColumn( column_id );
		if ( column_index < 0 )
			return "";

		return reader.StringSafe( column_index );
	}

	public static string StringSafe( this SqlDataReader reader , int column_index )
	{
		if ( reader.IsDBNull( column_index ) )
			return "";

		string? o = reader[ column_index ].ToString( );
		if ( o == null ) return "";

		return o!;
	}

	public static DateTime DateTime( this SqlDataReader reader , string column_id )
	{
		int column_index = reader.FindColumn( column_id );
		if ( column_index < 0 )
			return System.DateTime.MinValue;

		return reader.DateTime( column_index );
	}

	public static DateTime DateTime( this SqlDataReader reader , int column_index )
	{
		object data_value = reader[ column_index ];
		if ( data_value is DateTime date_time_result )
			return date_time_result;
		
		return System.DateTime.MinValue;
	}

	public static int Int( this SqlDataReader reader , string column_id , int fallback = 0 )
	{
		int column_index = reader.FindColumn( column_id );
		if ( column_index < 0 )
			return fallback;

		return reader.Int( column_index , fallback );
	}

	public static int Int( this SqlDataReader reader , int column_index , int fallback = 0 )
	{
		object data = reader[ column_index ];
		if ( data == null )
			return fallback;

		try
		{
			return Convert.ToInt32( data );
		}
		catch
		{
		}

		if ( int.TryParse( data.ToString( ) , out int result ) )
			return result;

		return fallback;
	}

	public static long Int64( this SqlDataReader reader , string column_id , long fallback )
	{
		int column_index = reader.FindColumn( column_id );
		if ( column_index < 0 )
			return fallback;

		return reader.Int64( column_index , fallback );
	}

	public static long Int64( this SqlDataReader reader , int column_index , long fallback )
	{
		object data = reader[ column_index ];
		if ( data == null )
			return fallback;

		try
		{
			return Convert.ToInt64( data );
		}
		catch
		{
		}

		if ( long.TryParse( data.ToString( ) , out long result ) )
			return result;

		return fallback;
	}

	public static decimal Numeric( this SqlDataReader reader , string column_id , decimal fallback )
	{
		int column_index = reader.FindColumn( column_id );
		if ( column_index < 0 )
			return fallback;

		return reader.Numeric( column_index , fallback );
	}

	public static decimal Numeric( this SqlDataReader reader , int column_index , decimal fallback )
	{
		SqlDecimal data = reader.GetSqlDecimal( column_index );
		if ( data.IsNull )
			return 0;
		return data.Value;
	}


	public static int FindColumn( this SqlDataReader reader , string column_id )
	{
		try
		{
			return reader.GetOrdinal( column_id );
		}
		catch ( Exception )
		{
			return -1;
		}
	}
}