move.hlp

来自「关系型数据库 Postgresql 6.5.2」· HLP 代码 · 共 44 行

.pgaw:Help.f.t insert end "MOVE" {bold} "allows a user to move cursor position a specified number of rows. MOVE works like the FETCH command, but only positions the cursor and does not return rows. 

Refer to the FETCH command for details on syntax and usage. 

" {} "Synopsis" {bold} "
" {} "
MOVE \[ selector \] \[ count \] 
    \{ IN | FROM \} cursor
FETCH \[ RELATIVE \] \[ \{ \[ # | ALL | NEXT | PRIOR \] \} \] FROM \] cursor


" {code} "Usage" {bold} "

                --set up and use a cursor:
                --
" {} "          BEGIN WORK;
                DECLARE liahona CURSOR  FOR SELECT * FROM films;
                
                --Skip first 5 rows:
                --
                MOVE FORWARD 5 IN liahona;
                                  MOVE
                
                --Fetch 6th row in the cursor liahona:
                --
                FETCH 1 IN liahona;
                                  FETCH
                  code |title |did| date_prod|kind      |len
                  -----+------+---+----------+----------+------
                  P_303|48 Hrs|103|1982-10-22|Action    | 01:37
                  (1 row)
                
                -- close the cursor liahona and commit work:
                --
                CLOSE liahona;
                COMMIT WORK;

" {code} "Notes" {bold} "

MOVE is a Postgres language extension. 

Refer to FETCH for a description of valid arguments. Refer to DECLARE to declare a cursor. Refer to BEGIN WORK, COMMIT WORK, ROLLBACK WORK statements for further \
information about transactions. "