比如 SELECT COUNT(*) FROM TB_01
可以改写成 SELECT ROWS FROM SYSINDEXES WHERE INDID<2 AND ID=OBJECT_ID()'TB_01'但是现在有一个问题,如果在 SELECT COUNT(*) FROM TB_01 后加上检索条件变成:
SELECT COUNT(*) FROM TB_01 WHERE COL_1='A'请问如何使用 SELECT ROWS FROM SYSINDEXES WHERE INDID<2 AND ID=OBJECT_ID()'TB_01' 这条SQL来加上条件获得跟
SELECT COUNT(*) FROM TB_01 WHERE COL_1='A'相同的结果?
可以改写成 SELECT ROWS FROM SYSINDEXES WHERE INDID<2 AND ID=OBJECT_ID()'TB_01'但是现在有一个问题,如果在 SELECT COUNT(*) FROM TB_01 后加上检索条件变成:
SELECT COUNT(*) FROM TB_01 WHERE COL_1='A'请问如何使用 SELECT ROWS FROM SYSINDEXES WHERE INDID<2 AND ID=OBJECT_ID()'TB_01' 这条SQL来加上条件获得跟
SELECT COUNT(*) FROM TB_01 WHERE COL_1='A'相同的结果?
貌似做不到 ,
不过 2008可以为行的子集做索引(08新特性)
例:CREATE NONCLUSTERED INDEX NCI_Unitprice_SalesOrderDetail
ON Sales.SalesOrderDetail(UnitPrice)
WHERE UnitPrice >= 150.00 AND UnitPrice <=175.00