IPgScrollableCustomScan<TState>

Namespace: Ankus

Assembly: Ankus.Runtime.dll

Reads a custom scan backward, so a cursor can fetch earlier rows without PostgreSQL storing the rows it has read.

public interface IPgScrollableCustomScan<TState> : IPgCustomScan<TState> where TState : class

Type parameters:

TState

The per-scan state.

The scan has a current row, the one the last read returned, like a cursor. Reading forward moves to the next row and reading backward to the previous one. A read that finds no row leaves the scan before the first row or after the last, so reading in the other direction then returns the first or the last row.

Methods

ReadBackward(TState, PgHeapTuple)

Reads the row before the current one.

public static abstract bool ReadBackward(TState state, PgHeapTuple row)

Parameters:

state — TState

The scan’s state.

row — PgHeapTuple

A new row of the table’s columns, all NULL until set.

Returns: bool

Whether a row was read; false leaves the scan before its first row.