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正则表达式

products表如下:

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1. 基本字符匹配

vcrH1NrV+7j2wdDL0cv3o6zWu9KqcHJvZF9uYW1l1tCw/LqswcvL+cvRy/e1xNfWt/u+zb/J0tTBy6OstvhMSUtFyOe5+7K708PNqMXkt/ujrMTHw7TSqsfzcHJvZF9uYW1l0+vL0cv3tcTX1rf70qrN6sirxqXF5KO60rK+zcrHy7XPwsPmtcTA/dfTo6zQ6NKqyrnTwyBMSUtFIA=="JetPack 1000'才可以适配搜索到。

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2 使用or进行匹配搜索,可以搜索两个条件,也可以连接多个条件:

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3 匹配几个字符之一://这个的意思是说,匹配1 Ton 或者 2 Ton 或者 3 Ton

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但是如果写成下面这样又是不对的://这个得意思是匹配1 或者 2 或者 3 Ton的列

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4 范围匹配,[1-5] 其实是 [12345]的简写,此外 [0-9],[3-9]都是合法的。

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5 匹配特殊字符,匹配特殊字符需要使用//

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6 匹配多个实例

重复元素字符:

元字符说明*0个或多个匹配+1个或多个匹配?0个或1个匹配{n}指定数目的匹配{n,}不少于指定数目的匹配{n,m}匹配数目的范围

下面搜索条件的意思是 首先要有一个右括号,接着应该有一个数字,然后是一个空格,再然后是sticks,最后是0个或1个左括号,问号的意思如上表所示

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7 字符种类 为了方便工作,可以使用预先定义的字符集,字符集如下:

类说明[:alpha:]任意字符[:blank:]空格和制表符[:cntrl:]ASCII控制字符(从ASCII0到31和127)[:digit:]任意数字同 [0-9][:graph:]任意可打印字符,但不包括空格[:lower:]任意小写字母[:print:]任意可打印字符[:punct:]即不在[:alnum:]又不在[:cntrl:]中的任意字符[:space:]包括空格在内的任意空白字符[:upper:]任意大写字母[:alnum:]任意字母和数字

接下来从表中搜索prod_name中 有连续4个数字的名字:其中[:digit:]表示任意的数字,{4}表示这个数字需要出现4次:

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8 定位符在特定的位置搜索

元字符说明^文本开始$文本的结尾[[:<:>:]]词的结尾
下面的语句时查找以数字或者 . 开头的prod_name




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