使用mongoose正则表达式与文本在mongo db中搜索 [英] Searching in mongo db using mongoose regex vs. text

问题描述

谁能解释一下两者之间的区别?

Can anyone please explain the difference between:

db.collection.find({ $text: { $search: "dog cat" } })

和

Product.find({ "drug": { "$regex": "cols", "$options": "i" } })

我们什么时候去哪一个?

When should we go for which one ?

推荐答案

$正则表达式

为查询中的模式匹配字符串提供正则表达式功能. MongoDB使用具有UTF-8支持的Perl兼容正则表达式(即"PCRE")版本8.36.

Provides regular expression capabilities for pattern matching strings in queries. MongoDB uses Perl compatible regular expressions (i.e. "PCRE" ) version 8.36 with UTF-8 support.

$ text

对使用文本索引索引的字段的内容执行文本搜索.

performs a text search on the content of the fields indexed with a text index.

---

用于数据

---

For data

{ "_id" : 100, "sku" : "abc123", "description" : "Single line description." }
{ "_id" : 101, "sku" : "abc789", "description" : "First line\nSecond line" }
{ "_id" : 102, "sku" : "xyz456", "description" : "Many spaces before     line" }
{ "_id" : 103, "sku" : "xyz789", "description" : "Multiple\nline description" }

要搜索作为单个字符串值的字段sku，可以使用$regex

To search field sku which is single string value, could use $regex

db.products.find( { sku: { $regex: /^ABC/i } } )

要搜索作为文本内容值的字段description，可以使用$text，当然，我们应该首先在description上建立文本索引.

Whereas to search field description which is text content value, could use $text, of course, we should build text index on description firstly.

db.products.find( { $text: { $search: "coffee" } } )

---

为什么不仅正则表达式?

---

Why not only regex?

• regular expressions有其自然的局限性，因为它们缺少任何词干功能，并且无法以简单的方式处理诸如action -superhero之类的便捷搜索查询.
• 它们不能使用传统索引，这会使大型数据集中的查询速度变慢.

• regular expressions have their natural limitations because they lack any stemming functionality and cannot handle convenient search queries such as "action -superhero" in a trivial way.
• they cannot use traditional indexes which makes queries in large datasets really slow.

这里有一个链接他们.

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