sql-server - 需要游标来读取提供的参数或所有记录，但不会读取所有

Question

当我填写并提供@Tract 参数时，我编写的程序运行良好。但是当我为参数发送一个空值时，过程没有完成，但表是空的。当我传递 null 时，我希望它为所有记录运行。谁能阐明我所缺少的东西？还是我想对光标功能做一个禁止？

ALTER PROCEDURE [dbo].[LoadworkINLoadTagReconciliation]
--Add parameters to procedure 
    @Tract VARCHAR(15),
    @TractType VARCHAR(2),
    @Status VARCHAR(1) 

AS
--Beginning of procedure
--Process 1: Insert tag records by tract
BEGIN

--Declare Variables and cursor 
    DECLARE @BeginTagNo INT
    DECLARE @EndTagNo INT
    DECLARE TagCursor CURSOR
        FOR SELECT MIN(BEGINTAGNO), MAX(ENDTAGNO) FROM dbo.INLoadTagReconciliation WHERE BEGINTAGNO <> 0 AND TYPE = 1 AND (TRACTCODE = @Tract OR @Tract = NULL) group by TRACTCODE, TAGKEY

--Check for Existance of workfile, drop and recreate if it exists
IF OBJECT_ID('workINLoadTagReconciliation') IS not NULL  
DROP TABLE dbo.workINLoadTagReconciliation
BEGIN
       CREATE TABLE workINLoadTagReconciliation (
              Tag INT, Type INT, TicketKey INT CONSTRAINT Tag_PK PRIMARY KEY CLUSTERED(Tag)
              ); 
END

--Open cursor holding stored records
OPEN TagCursor

--Load first records into cursor
FETCH NEXT FROM TagCursor
INTO @BeginTagNo, @EndTagNo

--Begin processing records for each tract. It will process how many ever records there are per tract then break out.
WHILE @@FETCH_STATUS = 0
BEGIN

--Here we use a cte (common table expression) to help create the numbering for the rows between the specified beginning and ending tags
       WITH
              L0   AS(SELECT 1 AS C UNION ALL SELECT 1 AS O), -- 2 rows
              L1   AS(SELECT 1 AS C FROM L0 AS A CROSS JOIN L0 AS B), -- 4 rows
              L2   AS(SELECT 1 AS C FROM L1 AS A CROSS JOIN L1 AS B), -- 16 rows
              L3   AS(SELECT 1 AS C FROM L2 AS A CROSS JOIN L2 AS B), -- 256 rows
              L4   AS(SELECT 1 AS C FROM L3 AS A CROSS JOIN L3 AS B), -- 65,536 rows
              L5   AS(SELECT 1 AS C FROM L4 AS A CROSS JOIN L4 AS B), -- 4,294,967,296 rows
              Nums AS(SELECT ROW_NUMBER() OVER(ORDER BY (SELECT NULL)) AS Tag FROM L5)

       INSERT INTO workINLoadTagReconciliation SELECT Tag, NULL, NULL FROM Nums WHERE Tag >= @BeginTagNo AND Tag <= @EndTagNo ORDER BY Tag
       FETCH NEXT FROM TagCursor
       INTO @BeginTagNo, @EndTagNo
END

--Now we close the cursor and destroy it with the deallocate command
CLOSE TagCursor
DEALLOCATE TagCursor 

标签： sql-server