chear

摘要： Selecting Rows Randomly from a Large Tablehttp://msdn.microsoft.com/en-us/library/cc441928.aspx语句如下： SELECT * FROM Table1 WHERE (ABS(CAST( (BINARY_CHECKSUM (keycol1, NEWID())) as int)) % 100) < 10select top 1 * from Table1 TABLESAMPLE(1000 ROWS) 阅读全文

摘要： 0: (Uninitialized) the send( ) method has not yet been invoked.1: (Loading) the send( ) method has been invoked, request in progress.2: (Loaded) the send( ) method has completed, entire response received.3: (Interactive) the response is being parsed.4: (Completed) the response has been parsed, is re 阅读全文

摘要： JS中逻辑&&和||运算数可以是任何类型的，不止是布尔型的。布尔型相对简单，本文只针对非布尔型或者二者都有的情况作说明.对于如下实例：var T = {}; function test() { var height = 0; var re = T || 100; alert(re);}对于&&运算符：1.如果运算数一个为空对象，true, 已定义的变量， 另一个为常量，如100，返回该常量对象。如： function test() { var height = 200; var re = height && 100; alert(re... 阅读全文