摘要:
New features in C# 4.0Mads Torgersen, C# Language PMJune 09IntroductionIt is now close to a year since Microsoft Visual C# 3.0 shipped as part of Visual Studio 2008. In the VS Managed Languages team w... 阅读全文
摘要:
Access支持三表或三表以上的join操作,但是要加括号,一层一层 JOIN 下去。例如:SELECT *FROM (aa LEFT JOIN bb ON aa.a = bb.a ) LEFT JOIN cc ON cc.a = bb.a;这里需要注意一个问题,在使用join语句查询时,只有第一个join后on的条件中可以加多个条件,后面的只能有一个条件,如:SELECT *FROM (aa L... 阅读全文