--测试表及数据
CREATE TABLE tb(Col varchar(10))
INSERT tb SELECT '12'
UNION ALL SELECT 'aa'
GO
--观察Transact-SQL语句的执行计划,而不是执行
SET SHOWPLAN_ALL ON
GO
SELECT * FROM tb
WHERE ISNUMERIC(Col)=1
AND Col BETWEEN 1 AND 100
GO
SET SHOWPLAN_ALL OFF
GO
--建立索引
CREATE INDEX IDX_tb_Col ON tb(Col)
GO
SET SHOWPLAN_ALL ON
GO
SELECT * FROM tb
WHERE ISNUMERIC(Col)=1
AND Col BETWEEN 1 AND 100
GO
SET SHOWPLAN_ALL OFF
GO
--删除测试
DROP TABLE tb
