2012年4月8日

摘要: SQL: COUNT FunctionThe COUNT function returns the number of rows in a query.The syntax for the COUNT function is:SELECT COUNT(expression)FROM tablesWHERE predicates;Note:The COUNT function will only count those records in which the field in the brackets is NOT NULL.For example, if you have the follo 阅读全文

posted @ 2012-04-08 13:18 郭 弈楠 阅读(152) 评论(0) 推荐(0) 编辑


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