數字可能信息不全，需要對數字進行切分，所以選用 ngram 分詞器進行分詞

測試

POST _analyze {"tokenizer": "ngram","text":"123456" }{"tokens" : [{"token" : "1","start_offset" : 0,"end_offset" : 1,"type" : "word","position" : 0},{"token" : "12","start_offset" : 0,"end_offset" : 2,"type" : "word","position" : 1},{"token" : "2","start_offset" : 1,"end_offset" : 2,"type" : "word","position" : 2},{"token" : "23","start_offset" : 1,"end_offset" : 3,"type" : "word","position" : 3},{"token" : "3","start_offset" : 2,"end_offset" : 3,"type" : "word","position" : 4},{"token" : "34","start_offset" : 2,"end_offset" : 4,"type" : "word","position" : 5},{"token" : "4","start_offset" : 3,"end_offset" : 4,"type" : "word","position" : 6},{"token" : "45","start_offset" : 3,"end_offset" : 5,"type" : "word","position" : 7},{"token" : "5","start_offset" : 4,"end_offset" : 5,"type" : "word","position" : 8},{"token" : "56","start_offset" : 4,"end_offset" : 6,"type" : "word","position" : 9},{"token" : "6","start_offset" : 5,"end_offset" : 6,"type" : "word","position" : 10}] }

創建mapping

PUT test {"settings": {"analysis": {"analyzer": {"my_analyzer": {"tokenizer": "my_tokenizer"}},"tokenizer": {"my_tokenizer": {"type": "ngram","min_gram": 3,"max_gram": 4,"token_chars": ["letter","digit"]}}}}, "mappings": {"properties": {"name":{"type": "text","analyzer": "my_analyzer"}}} } POST test/_analyze {"analyzer": "my_analyzer","text":"渝A253DC" }{"tokens" : [{"token" : "渝A2","start_offset" : 0,"end_offset" : 3,"type" : "word","position" : 0},{"token" : "渝A25","start_offset" : 0,"end_offset" : 4,"type" : "word","position" : 1},{"token" : "A25","start_offset" : 1,"end_offset" : 4,"type" : "word","position" : 2},{"token" : "A253","start_offset" : 1,"end_offset" : 5,"type" : "word","position" : 3},{"token" : "253","start_offset" : 2,"end_offset" : 5,"type" : "word","position" : 4},{"token" : "253D","start_offset" : 2,"end_offset" : 6,"type" : "word","position" : 5},{"token" : "53D","start_offset" : 3,"end_offset" : 6,"type" : "word","position" : 6},{"token" : "53DC","start_offset" : 3,"end_offset" : 7,"type" : "word","position" : 7},{"token" : "3DC","start_offset" : 4,"end_offset" : 7,"type" : "word","position" : 8}] } POST test/_analyze {"analyzer": "my_analyzer","text":"123456" }{"tokens" : [{"token" : "123","start_offset" : 0,"end_offset" : 3,"type" : "word","position" : 0},{"token" : "1234","start_offset" : 0,"end_offset" : 4,"type" : "word","position" : 1},{"token" : "234","start_offset" : 1,"end_offset" : 4,"type" : "word","position" : 2},{"token" : "2345","start_offset" : 1,"end_offset" : 5,"type" : "word","position" : 3},{"token" : "345","start_offset" : 2,"end_offset" : 5,"type" : "word","position" : 4},{"token" : "3456","start_offset" : 2,"end_offset" : 6,"type" : "word","position" : 5},{"token" : "456","start_offset" : 3,"end_offset" : 6,"type" : "word","position" : 6}] }

錯誤提示：

The difference between max_gram and min_gram in NGram Tokenizer must be less than or equal to: [1] but was [7]. This limit can be set by changing the [index.max_ngram_diff] index level setting。
從ES 7.0 以上，需要從新對 index.max_ngram_diff 進行設置

重構mapping

PUT test {"settings": {"index.max_ngram_diff":8,"analysis": {"analyzer": {"my_analyzer": {"tokenizer": "my_tokenizer"}},"tokenizer": {"my_tokenizer": {"type": "ngram","min_gram": 1,"max_gram": 8,"token_chars": ["letter","digit"]}}}}, "mappings": {"properties": {"name":{"type": "text","analyzer": "my_analyzer"}}} } POST test/_analyze {"analyzer": "my_analyzer","text":"123456" } {"tokens" : [{"token" : "1","start_offset" : 0,"end_offset" : 1,"type" : "word","position" : 0},{"token" : "12","start_offset" : 0,"end_offset" : 2,"type" : "word","position" : 1},{"token" : "123","start_offset" : 0,"end_offset" : 3,"type" : "word","position" : 2},{"token" : "1234","start_offset" : 0,"end_offset" : 4,"type" : "word","position" : 3},{"token" : "12345","start_offset" : 0,"end_offset" : 5,"type" : "word","position" : 4},{"token" : "123456","start_offset" : 0,"end_offset" : 6,"type" : "word","position" : 5},{"token" : "2","start_offset" : 1,"end_offset" : 2,"type" : "word","position" : 6},{"token" : "23","start_offset" : 1,"end_offset" : 3,"type" : "word","position" : 7},{"token" : "234","start_offset" : 1,"end_offset" : 4,"type" : "word","position" : 8},{"token" : "2345","start_offset" : 1,"end_offset" : 5,"type" : "word","position" : 9},{"token" : "23456","start_offset" : 1,"end_offset" : 6,"type" : "word","position" : 10},{"token" : "3","start_offset" : 2,"end_offset" : 3,"type" : "word","position" : 11},{"token" : "34","start_offset" : 2,"end_offset" : 4,"type" : "word","position" : 12},{"token" : "345","start_offset" : 2,"end_offset" : 5,"type" : "word","position" : 13},{"token" : "3456","start_offset" : 2,"end_offset" : 6,"type" : "word","position" : 14},{"token" : "4","start_offset" : 3,"end_offset" : 4,"type" : "word","position" : 15},{"token" : "45","start_offset" : 3,"end_offset" : 5,"type" : "word","position" : 16},{"token" : "456","start_offset" : 3,"end_offset" : 6,"type" : "word","position" : 17},{"token" : "5","start_offset" : 4,"end_offset" : 5,"type" : "word","position" : 18},{"token" : "56","start_offset" : 4,"end_offset" : 6,"type" : "word","position" : 19},{"token" : "6","start_offset" : 5,"end_offset" : 6,"type" : "word","position" : 20}] }

延伸：edgeNGram

ngram 的簡化版，單個分詞，以首字母為起始位置，進行分詞
效果如下

PUT test {"settings": {"analysis": {"analyzer": {"my_analyzer": {"tokenizer": "my_tokenizer"}},"tokenizer": {"my_tokenizer": {"type": "edgeNGram","min_gram": 1,"max_gram": 8,"token_chars": ["letter","digit"]}}}}, "mappings": {"properties": {"name":{"type": "text","analyzer": "my_analyzer"}}} } POST test/_analyze {"analyzer": "my_analyzer","text":"123456" } {"tokens" : [{"token" : "1","start_offset" : 0,"end_offset" : 1,"type" : "word","position" : 0},{"token" : "12","start_offset" : 0,"end_offset" : 2,"type" : "word","position" : 1},{"token" : "123","start_offset" : 0,"end_offset" : 3,"type" : "word","position" : 2},{"token" : "1234","start_offset" : 0,"end_offset" : 4,"type" : "word","position" : 3},{"token" : "12345","start_offset" : 0,"end_offset" : 5,"type" : "word","position" : 4},{"token" : "123456","start_offset" : 0,"end_offset" : 6,"type" : "word","position" : 5}] }

總結

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