Class ReaderExtensions

Extends Npgsql.NpgsqlDataReader with useful methods.

Inheritance

object

ReaderExtensions

Namespace: Neon.Postgres

Assembly: Neon.Postgres.dll

Syntax

public static class ReaderExtensions

Methods

GetNullableBoolean(NpgsqlDataReader, int)

Returns the column value as a nullable boolean.

Declaration

public static bool? GetNullableBoolean(this NpgsqlDataReader reader, int ordinal)

Parameters

Type	Name	Description
NpgsqlDataReader	reader	The data reader.
int	ordinal	The zero-based column position.

Returns

Type	Description
bool?	The nullable column value.

GetNullableByte(NpgsqlDataReader, int)

Returns the column value as a nullable byte.

Declaration

public static byte? GetNullableByte(this NpgsqlDataReader reader, int ordinal)

Parameters

Type	Name	Description
NpgsqlDataReader	reader	The data reader.
int	ordinal	The zero-based column position.

Returns

Type	Description
byte?	The nullable column value.

GetNullableChar(NpgsqlDataReader, int)

Returns the column value as a nullable character.

Declaration

public static char? GetNullableChar(this NpgsqlDataReader reader, int ordinal)

Parameters

Type	Name	Description
NpgsqlDataReader	reader	The data reader.
int	ordinal	The zero-based column position.

Returns

Type	Description
char?	The nullable column value.

GetNullableDateTime(NpgsqlDataReader, int)

Returns the column value as a nullable DateTime.

Declaration

public static DateTime? GetNullableDateTime(this NpgsqlDataReader reader, int ordinal)

Parameters

Type	Name	Description
NpgsqlDataReader	reader	The data reader.
int	ordinal	The zero-based column position.

Returns

Type	Description
Nullable	The nullable column value.

GetNullableDecimal(NpgsqlDataReader, int)

Returns the column value as a nullable decimal.

Declaration

public static decimal? GetNullableDecimal(this NpgsqlDataReader reader, int ordinal)

Parameters

Type	Name	Description
NpgsqlDataReader	reader	The data reader.
int	ordinal	The zero-based column position.

Returns

Type	Description
decimal?	The nullable column value.

GetNullableDouble(NpgsqlDataReader, int)

Returns the column value as a nullable double.

Declaration

public static double? GetNullableDouble(this NpgsqlDataReader reader, int ordinal)

Parameters

Type	Name	Description
NpgsqlDataReader	reader	The data reader.
int	ordinal	The zero-based column position.

Returns

Type	Description
double?	The nullable column value.

GetNullableFloat(NpgsqlDataReader, int)

Returns the column value as a nullable float.

Declaration

public static float? GetNullableFloat(this NpgsqlDataReader reader, int ordinal)

Parameters

Type	Name	Description
NpgsqlDataReader	reader	The data reader.
int	ordinal	The zero-based column position.

Returns

Type	Description
float?	The nullable column value.

GetNullableGuid(NpgsqlDataReader, int)

Returns the column value as a nullable Guid.

Declaration

public static Guid? GetNullableGuid(this NpgsqlDataReader reader, int ordinal)

Parameters

Type	Name	Description
NpgsqlDataReader	reader	The data reader.
int	ordinal	The zero-based column position.

Returns

Type	Description
Guid?	The nullable column value.

GetNullableInt16(NpgsqlDataReader, int)

Returns the column value as a nullable short.

Declaration

public static short? GetNullableInt16(this NpgsqlDataReader reader, int ordinal)

Parameters

Type	Name	Description
NpgsqlDataReader	reader	The data reader.
int	ordinal	The zero-based column position.

Returns

Type	Description
short?	The nullable column value.

GetNullableInt32(NpgsqlDataReader, int)

Returns the column value as a nullable int.

Declaration

public static int? GetNullableInt32(this NpgsqlDataReader reader, int ordinal)

Parameters

Type	Name	Description
NpgsqlDataReader	reader	The data reader.
int	ordinal	The zero-based column position.

Returns

Type	Description
int?	The nullable column value.

GetNullableInt64(NpgsqlDataReader, int)

Returns the column value as a nullable long.

Declaration

public static long? GetNullableInt64(this NpgsqlDataReader reader, int ordinal)

Parameters

Type	Name	Description
NpgsqlDataReader	reader	The data reader.
int	ordinal	The zero-based column position.

Returns

Type	Description
long?	The nullable column value.

GetNullableString(NpgsqlDataReader, int)

Returns the column value as a string. Unlike GetStream(int), this method can handle null column values.

Declaration

public static string GetNullableString(this NpgsqlDataReader reader, int ordinal)

Parameters

Type	Name	Description
NpgsqlDataReader	reader	The data reader.
int	ordinal	The zero-based column position.

Returns

Type	Description
string	The column string or null.

GetNullableTimeSpan(NpgsqlDataReader, int)

Returns the column value as a nullable TimeSpan.

Declaration

public static TimeSpan? GetNullableTimeSpan(this NpgsqlDataReader reader, int ordinal)

Parameters

Type	Name	Description
NpgsqlDataReader	reader	The data reader.
int	ordinal	The zero-based column position.

Returns

Type	Description
TimeSpan?	The nullable column value.

ToAsyncEnumerable(NpgsqlDataReader)

Returns an enumerator suitable for enumerating database results asynchronously.

Declaration

public static ReaderAsyncEnumerator ToAsyncEnumerable(this NpgsqlDataReader reader)

Parameters

Type	Name	Description
NpgsqlDataReader	reader	The data reader.

Returns

Type	Description
ReaderAsyncEnumerator	The ReaderAsyncEnumerator.

Remarks

This method provides a clean way to asynchronousl enumerate database results using the C# await nforeach statement or the equivalent in of the .NET languages. Here's an example:

using (var reader = await postgres.ExecuteReaderAsync("SELECT value FROM enumerate_table;"))
{
    await foreach (var row in reader.ToAsyncEnumerable())
    {
        values.Add(row.GetInt32(0));
    }
}

ToEnumerable(NpgsqlDataReader)

Returns an enumerator suitable for enumerating database results synchronously.

Declaration

public static ReaderEnumerator ToEnumerable(this NpgsqlDataReader reader)

Parameters

Type	Name	Description
NpgsqlDataReader	reader	The data reader.

Returns

Type	Description
ReaderEnumerator	The ReaderEnumerator.

Remarks

This method provides a clean way to enumerate database results using the C# foreach statement or the equivalent in of the .NET languages. Here's an example:

using (var reader = postgres.ExecuteReader("SELECT value FROM enumerate_table;"))
{
    foreach (var row in reader.ToEnumerable())
    {
        values.Add(row.GetInt32(0));
    }
}