随记

1.DCOMCNFG

2.update TableName set Column = rand(checksum(newid()))

3.在SSIS的数据类型中有DT_DATE和DT_DBTIMESTAMP,这两个数据类型都可以精确到时分秒,那

他们之间有什么区别呢,英文好的阅读一下MSDN的解释:

DT_DATE:A date structure that consists of year, month, day, and hour.

The DT_DATE data type is implemented using an 8-byte floating-point number. Days are represented by whole number increments, starting with 30 December 1899, and midnight as time zero. Hour values are expressed as the absolute value of the fractional part of the number. This means that DT_DATE can represent minutes, seconds, and even milliseconds as well. However, floating point value cannot represent all real values; therefore, there are limits on the range of dates that can be presented in DT_DATE

DT_DBTIMESTAMPA timestamp structure that consists of year, month, day, hour, minute, second, and fractional seconds. The fractional seconds have a maximum scale of 3 digits

按照我个人的理解,DT_DBTIMESTAMPDT_DATE的时间显示更精确,而DT_DATE只能精确到天,小时以后就可能出现误差

4. INFORMATION_SCHEMA.COLUMNS

SET QUOTED_IDENTIFIER:http://www.cnblogs.com/xmaiC/archive/2009/04/16/1436862.html

原文地址:https://www.cnblogs.com/wanglg/p/3542861.html