SQL Server 竞态条件问题

**SQL Server 竞态条件问题**

sql
-- 创建一个测试表
CREATE TABLE TestTable (
    ID INT PRIMARY KEY,
    Value INT
);
-- 初始化数据
INSERT INTO TestTable (ID, Value) VALUES (1, 0);
-- 进程 A
BEGIN TRANSACTION;
    DECLARE @AValue INT;
    SELECT @AValue = Value FROM TestTable WHERE ID = 1;
    WAITFOR DELAY '00:00:05'; -- 模拟耗时操作
    SET @AValue = @AValue + 1;
    UPDATE TestTable SET Value = @AValue WHERE ID = 1;
COMMIT;
-- 进程 B
BEGIN TRANSACTION;
    DECLARE @BValue INT;
    SELECT @BValue = Value FROM TestTable WHERE ID = 1;
    WAITFOR DELAY '00:00:02'; -- 模拟耗时操作
    SET @BValue = @BValue + 1;
    UPDATE TestTable SET Value = @BValue WHERE ID = 1;
COMMIT;
-- 查询结果
SELECT Value FROM TestTable WHERE ID = 1;