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Class NpgsqlBinaryExporter

Provides an API for a binary COPY TO operation, a high-performance data export mechanism from a PostgreSQL table. Initiated by BeginBinaryExport(String)

Inheritance
System.Object
NpgsqlBinaryExporter
Implements
System.IDisposable
IAsyncDisposable
Inherited Members
System.Object.ToString()
System.Object.Equals(System.Object)
System.Object.Equals(System.Object, System.Object)
System.Object.ReferenceEquals(System.Object, System.Object)
System.Object.GetHashCode()
System.Object.GetType()
System.Object.MemberwiseClone()
Namespace: Npgsql
Assembly: Npgsql.dll
Syntax
public sealed class NpgsqlBinaryExporter : ICancelable, IDisposable, IAsyncDisposable

Properties

IsNull

Returns whether the current column is null.

Declaration
public bool IsNull { get; }
Property Value
Type Description
System.Boolean

Methods

Cancel()

Cancels an ongoing export.

Declaration
public void Cancel()

Dispose()

Completes that binary export and sets the connection back to idle state

Declaration
public void Dispose()

DisposeAsync()

Async completes that binary export and sets the connection back to idle state

Declaration
public ValueTask DisposeAsync()
Returns
Type Description
ValueTask

Read<T>()

Reads the current column, returns its value and moves ahead to the next column. If the column is null an exception is thrown.

Declaration
public T Read<T>()
Returns
Type Description
T

The value of the column

Type Parameters
Name Description
T

The type of the column to be read. This must correspond to the actual type or data corruption will occur. If in doubt, use Read<T>(NpgsqlDbType) to manually specify the type.

Read<T>(NpgsqlDbType)

Reads the current column, returns its value according to type and moves ahead to the next column. If the column is null an exception is thrown.

Declaration
public T Read<T>(NpgsqlDbType type)
Parameters
Type Name Description
NpgsqlDbType type

In some cases T isn't enough to infer the data type coming in from the database. This parameter and be used to unambiguously specify the type. An example is the JSONB type, for which T will be a simple string but for which type must be specified as Jsonb.

Returns
Type Description
T

The value of the column

Type Parameters
Name Description
T

The .NET type of the column to be read.

ReadAsync<T>(NpgsqlDbType, CancellationToken)

Reads the current column, returns its value according to type and moves ahead to the next column. If the column is null an exception is thrown.

Declaration
public ValueTask<T> ReadAsync<T>(NpgsqlDbType type, CancellationToken cancellationToken = default(CancellationToken))
Parameters
Type Name Description
NpgsqlDbType type

In some cases T isn't enough to infer the data type coming in from the database. This parameter and be used to unambiguously specify the type. An example is the JSONB type, for which T will be a simple string but for which type must be specified as Jsonb.

System.Threading.CancellationToken cancellationToken
Returns
Type Description
ValueTask<T>

The value of the column

Type Parameters
Name Description
T

The .NET type of the column to be read.

ReadAsync<T>(CancellationToken)

Reads the current column, returns its value and moves ahead to the next column. If the column is null an exception is thrown.

Declaration
public ValueTask<T> ReadAsync<T>(CancellationToken cancellationToken = default(CancellationToken))
Parameters
Type Name Description
System.Threading.CancellationToken cancellationToken
Returns
Type Description
ValueTask<T>

The value of the column

Type Parameters
Name Description
T

The type of the column to be read. This must correspond to the actual type or data corruption will occur. If in doubt, use Read<T>(NpgsqlDbType) to manually specify the type.

Skip()

Skips the current column without interpreting its value.

Declaration
public void Skip()

SkipAsync(CancellationToken)

Skips the current column without interpreting its value.

Declaration
public Task SkipAsync(CancellationToken cancellationToken = default(CancellationToken))
Parameters
Type Name Description
System.Threading.CancellationToken cancellationToken
Returns
Type Description
System.Threading.Tasks.Task

StartRow()

Starts reading a single row, must be invoked before reading any columns.

Declaration
public int StartRow()
Returns
Type Description
System.Int32

The number of columns in the row. -1 if there are no further rows. Note: This will currently be the same value for all rows, but this may change in the future.

StartRowAsync(CancellationToken)

Starts reading a single row, must be invoked before reading any columns.

Declaration
public ValueTask<int> StartRowAsync(CancellationToken cancellationToken = default(CancellationToken))
Parameters
Type Name Description
System.Threading.CancellationToken cancellationToken
Returns
Type Description
ValueTask<System.Int32>

The number of columns in the row. -1 if there are no further rows. Note: This will currently be the same value for all rows, but this may change in the future.

Implements

System.IDisposable
IAsyncDisposable
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