Postgresql 中文操作指南

SPI_scroll_cursor_move

SPI_scroll_cursor_move——移动游标

SPI_scroll_cursor_move — move a cursor

Synopsis

void SPI_scroll_cursor_move(Portal portal, FetchDirection direction,
                            long count)

Description

SPI_scroll_cursor_move 跳过游标中的一些行数。它等同于 SQL 命令 MOVE 。

SPI_scroll_cursor_move skips over some number of rows in a cursor. This is equivalent to the SQL command MOVE.

Arguments

  • Portal _portal_

    • portal containing the cursor

  • FetchDirection _direction_

    • one of FETCH_FORWARD, FETCH_BACKWARD, FETCH_ABSOLUTE or FETCH_RELATIVE

  • long _count_

    • number of rows to move for FETCH_FORWARD or FETCH_BACKWARD; absolute row number to move to for FETCH_ABSOLUTE; or relative row number to move to for FETCH_RELATIVE

Return Value

成功执行时 SPI_processed 设置如 SPI_execute 中所述。 SPI_tuptable 设置为 NULL ，因为此函数不返回任何行。

SPI_processed is set as in SPI_execute if successful. SPI_tuptable is set to NULL, since no rows are returned by this function.

Notes

有关 direction 和 count 参数解释的详细信息，请参阅 SQL FETCH 命令。

See the SQL FETCH command for details of the interpretation of the direction and count parameters.

如果未使用 CURSOR_OPT_SCROLL 选项创建游标的计划，则 FETCH_FORWARD 以外の其他方向值可能会失败。

Direction values other than FETCH_FORWARD may fail if the cursor’s plan was not created with the CURSOR_OPT_SCROLL option.