java - Neo4j - 按相关性排序

Question

我想在 Neo4j 中按相关性对返回的数据进行排序。

就我而言，相关性可以简化为“我正在搜索的词的索引”，其中索引越低相关性越高。

示例

我有这三个节点:

node : {
    Label: PROD
    properties : {
        name: "Bearing replacement Skateboard"
    }
}

node : {
    Label: PROD
    properties : {
        name: "Skateboard"
    }
}

node : {
    Label: PROD
    properties : {
        name: "L7 Skateboard"
    }
}

我希望它们与此订单一起退回:

node : {
    Label: PROD
    properties : {
        name: "Skateboard" // name.indexOf("Skateboard") = 0
    }
}

node : {
    Label: PROD
    properties : {
        name: "L7 Skateboard"  // name.indexOf("Skateboard") = 3
    }
}

node : {
    Label: PROD
    properties : {
        name: "Bearing replacement Skateboard"  // name.indexOf("Skateboard") = 19
    }
}

我目前拥有的:

String query = "MATCH (n:PROD) where LOWER(n.name) CONTAINS LOWER({textToSearch}) RETURN n ORDER BY LOWER(n.name) ASC LIMIT 15";

String textToSearch = "Skateboard";

Map<String, Object> queryParams = new HashMap<>();
queryParams.put("textToSearch", textToSearch);
try (
    Transaction ignored = database.beginTx();
    Result resultSet = database.execute(query, queryParams)
) {
    Iterator<Node> results = resultSet.columnAs("n");
    while (results.hasNext()) {
        Node node = results.next();
        /* data processing here */
    }
}

这只是按名称升序排列结果。有没有办法告诉 neo4j 基于 n.name.indexOf({textToFind}) 进行排序？

Answer 1

在 Cypher 中做这样的事情怎么样

MATCH (n:PROD) 
WHERE n.name_lc CONTAINS toLower({textToSearch})
WITH n, SPLIT(n.name_lc, toLower({textToSearch})) as parts
RETURN n.name, SIZE(parts[0]) AS leading
ORDER BY leading

要有效利用上述...

在属性的小写版本上创建索引

CREATE INDEX ON :PROD(name_lc)

将常规名称复制为小写版本

MATCH (n:PPOD)
SET n.name_lc = toLower(n.name)