SQL Server Books Online上面搜索like,找到了包含%，_,[],[^]几个通配符。
如：select * from mybbs where Content like '[w]%'
like关键字用于搜索匹配某个模式的字符串，或者日期，时间值。
SQL Server Books中的部分解释如下：

Pattern Matching in Search Conditions

The LIKE keyword uses a regular expression to contain the pattern that the values are matched against. The pattern contains the character string to search for, which can contain any combination of four wildcards.