server|sqlserver
1.分批取數
declare @P1 int
set @P1=180150000
declare @P2 int
set @P2=8
declare @P3 int
set @P3=1
declare @P4 int
set @P4=3
exec sp_cursoropen @P1 output,
N'select top 3 * from authors',
@P2 output,
@P3 output,
@P4 output
select @P1 , @P2 , @P3 , @P4
go
exec sp_cursorfetch 180150000, 16, 1, 1
go
exec sp_cursorfetch 180150000, 16, 2, 1
go
exec sp_cursorfetch 180150000, 16, 3, 1
go
exec sp_cursorfetch 180150000, 16, 4, 1
go
exec sp_cursorclose 180150000
go
The table-valued function fn_FindReports(InEmpID), which -- given an Employee ID -- returns a table corresponding to all the employees that report to the given employee directly or indirectly. This logic is not expressible in a single query and is a good candidate for implementing as a user-defined function.
CREATE FUNCTION fn_FindReports (@InEmpId nchar(5))
RETURNS @retFindReports TABLE (empid nchar(5) primary key,
empname nvarchar(50) NOT NULL,
mgrid nchar(5),
title nvarchar(30))
/*Returns a result set that lists all the employees who report to given
employee directly or indirectly.*/
AS
BEGIN
DECLARE @RowsAdded int
-- table variable to hold accumulated results
DECLARE @reports TABLE (empid nchar(5) primary key,
empname nvarchar(50) NOT NULL,
mgrid nchar(5),
title nvarchar(30),
processed tinyint default 0)
-- initialize @Reports with direct reports of the given employee
INSERT @reports
SELECT empid, empname, mgrid, title, 0
FROM employees
WHERE empid = @InEmpId
SET @RowsAdded = @@rowcount
-- While new employees were added in the previous iteration
WHILE @RowsAdded > 0
BEGIN
/*Mark all employee records whose direct reports are going to be
found in this iteration with processed=1.*/
UPDATE @reports
SET processed = 1
WHERE processed = 0
-- Insert employees who report to employees marked 1.
INSERT @reports
SELECT e.empid, e.empname, e.mgrid, e.title, 0
FROM employees e, @reports r
WHERE e.mgrid=r.empid and e.mgrid <> e.empid and r.processed = 1
SET @RowsAdded = @@rowcount
/*Mark all employee records whose direct reports have been found
in this iteration.*/
UPDATE @reports
SET processed = 2
WHERE processed = 1
END
-- copy to the result of the function the required columns
INSERT @retFindReports
SELECT empid, empname, mgrid, title
FROM @reports
RETURN
END
GO
