DB
FunctionsWindow

lag

Returns the value of an expression evaluated on a row that is a given number of rows before the current row within the window partition. An optional default is returned when the offset is out of ra…

lag(…) → Dynamic

Kind · window

Returns the value of an expression evaluated on a row that is a given number of rows before the current row within the window partition. An optional default is returned when the offset is out of range.

Part of the Window family.

first_value

Returns the value of an expression from the first row of the current window frame.

lag_in_frame

Like lag, but the offset is constrained to the current window frame rather than the whole partition. Returns NULL (or the provided default) when the referenced row is outside the frame.