SELECT a.*, b.HITS_COUNT AS Expr1, b.IP_COUNT AS Expr2,
isnull(a.VISIT_COUNT,0) + isnull(b.HITS_COUNT,0) AS Expr3
FROM STAT_DAY_REPORT a LEFT OUTER JOIN
STAT_MMS_REPORT b ON YEAR(a.VISIT_DATE) = YEAR(b.VISIT_DATE) AND
MONTH(a.VISIT_DATE) = MONTH(b.VISIT_DATE) AND DAY(a.VISIT_DATE)
= DAY(b.VISIT_DATE)
isnull(a.VISIT_COUNT,0) + isnull(b.HITS_COUNT,0) AS Expr3
FROM STAT_DAY_REPORT a LEFT OUTER JOIN
STAT_MMS_REPORT b ON YEAR(a.VISIT_DATE) = YEAR(b.VISIT_DATE) AND
MONTH(a.VISIT_DATE) = MONTH(b.VISIT_DATE) AND DAY(a.VISIT_DATE)
= DAY(b.VISIT_DATE)
isnull(a.VISIT_COUNT,0) + isnull(b.HITS_COUNT,0) AS Expr3
FROM STAT_DAY_REPORT a LEFT OUTER JOIN
STAT_MMS_REPORT b ON YEAR(a.VISIT_DATE) = YEAR(b.VISIT_DATE) AND
MONTH(a.VISIT_DATE) = MONTH(b.VISIT_DATE) AND DAY(a.VISIT_DATE)
= DAY(b.VISIT_DATE)
a.VISIT_COUNT + isnull(b.HITS_COUNT,0) AS Expr3
如果该字段为NULL值的时候,就为0了
使用指定的替换值替换 NULL。语法
ISNULL ( check_expression , replacement_value ) 参数
check_expression将被检查是否为 NULL的表达式。check_expression 可以是任何类型的。replacement_value在 check_expression 为 NULL时将返回的表达式。replacement_value 必须与 check_expresssion 具有相同的类型。 返回类型
返回与 check_expression 相同的类型。注释
如果 check_expression 不为 NULL,那么返回该表达式的值;否则返回 replacement_value。
isnull(a.VISIT_COUNT,0) + isnull(b.HITS_COUNT,0) AS Expr3
FROM STAT_DAY_REPORT a LEFT OUTER JOIN
STAT_MMS_REPORT b ON YEAR(a.VISIT_DATE) = YEAR(b.VISIT_DATE) AND
MONTH(a.VISIT_DATE) = MONTH(b.VISIT_DATE) AND DAY(a.VISIT_DATE)
= DAY(b.VISIT_DATE)
SELECT a.*, b.HITS_COUNT AS Expr1, b.IP_COUNT AS Expr2,
a.VISIT_COUNT+ isnull(b.HITS_COUNT,0) AS Expr3
FROM STAT_DAY_REPORT a LEFT OUTER JOIN
STAT_MMS_REPORT b ON YEAR(a.VISIT_DATE) = YEAR(b.VISIT_DATE) AND
MONTH(a.VISIT_DATE) = MONTH(b.VISIT_DATE) AND DAY(a.VISIT_DATE)
= DAY(b.VISIT_DATE)