MongoDB, una de las principales bases de datos NoSQL, es conocida por su rápido rendimiento, su esquema versátil, su escalabilidad y sus excelentes capacidades de indexación. Veamos un poco de contexto antes de entrar en algunos detalles. La búsqueda de texto completo es una función esencial cuando hablamos de encontrar contenido en Internet. Una búsqueda en Google es el mejor ejemplo de esto cuando vemos el contenido usando las frases o palabras clave. En este artículo, aprenderemos sobre las capacidades de búsqueda de texto completo en MongoDB basadas en el índice de texto.
Crear una base de datos de muestra
Antes de comenzar, crearemos una base de datos de muestra que se utilizará durante el tutorial.
Crearemos una base de datos con el nombre myDB y crea una colección con el nombre books . Para ello, el enunciado sería el siguiente.
> use myDB
> db.createCollection("books")
>Insertemos algunos documentos usando la siguiente declaración.
> db.books.insert([
{
"title": "Eloquent JavaScript, Second Edition",
"subtitle": "A Modern Introduction to Programming",
"author": "Marijn Haverbeke",
"publisher": "No Starch Press",
"description": "JavaScript lies at the heart of almost every modern web application, from social apps to the newest browser-based games. Though simple for beginners to pick up and play with, JavaScript is a flexible, complex language that you can use to build full-scale applications."
},
{
"title": "Learning JavaScript Design Patterns",
"subtitle": "A JavaScript and jQuery Developer's Guide",
"author": "Addy Osmani",
"publisher": "O'Reilly Media",
"description": "With Learning JavaScript Design Patterns, you'll learn how to write beautiful, structured, and maintainable JavaScript by applying classical and modern design patterns to the language. If you want to keep your code efficient, more manageable, and up-to-date with the latest best practices, this book is for you."
},
{
"title": "Speaking JavaScript",
"subtitle": "An In-Depth Guide for Programmers",
"author": "Axel Rauschmayer",
"publisher": "O'Reilly Media",
"description": "Like it or not, JavaScript is everywhere these days, from browser to server to mobile and now you, too, need to learn the language or dive deeper than you have. This concise book guides you into and through JavaScript, written by a veteran programmer who once found himself in the same position."
},
{
"title": "Programming JavaScript Applications",
"subtitle": "Robust Web Architecture with Node, HTML5, and Modern JS Libraries",
"author": "Eric Elliott",
"publisher": "O'Reilly Media",
"description": "Take advantage of JavaScript's power to build robust web-scale or enterprise applications that are easy to extend and maintain. By applying the design patterns outlined in this practical book, experienced JavaScript developers will learn how to write flexible and resilient code that's easier-yes, easier-to work with as your codebase grows."
},
{
"title": "Understanding ECMAScript 6",
"subtitle": "The Definitive Guide for JavaScript Developers",
"author": "Nicholas C. Zakas",
"publisher": "No Starch Press",
"description": "ECMAScript 6 represents the biggest update to the core of JavaScript in the history of the language. In Understanding ECMAScript 6, expert developer Nicholas C. Zakas provides a complete guide to the object types, syntax, and other exciting changes that ECMAScript 6 brings to JavaScript."
}
])Creando un índice de texto
Necesitamos crear un índice de texto en los campos para realizar la búsqueda de texto. Podemos crear esto en campos únicos o múltiples. La siguiente declaración creará un índice de texto en un solo campo.
>db.books.createIndex({"description":"text"})Crearemos un índice de texto en la descripción y subtítulo campos para este tutorial. Podemos crear solo un índice de texto por colección en MongoDB. Entonces crearemos un índice de texto compuesto usando la siguiente declaración.
>db.books.createIndex({"subtitle":"text","description":"text"})$buscar
Ahora intentaremos buscar documentos que tengan las palabras clave 'ECMAScript' en la descripción y subtítulo los campos. Para esto, podemos usar la siguiente declaración.
db.books.find({$text: {$search: "ECMAScript"}})Ejemplo
>db.books.find({$text: {$search: "ECMAScript"}},{ subtitle: 1, description: 1 })
{
"_id" : ObjectId("602b09cb3cb6144ada1c62fe"),
"subtitle" : "The Definitive Guide for JavaScript Developers",
"description" : "ECMAScript 6 represents the biggest update to the core of JavaScript in the history of the language. In Understanding ECMAScript 6, expert developer Nicholas C. Zakas provides a complete guide to the object types, syntax, and other exciting changes that ECMAScript 6 brings to JavaScript."
}
>Frases
Puede buscar frases utilizando el índice de texto. De forma predeterminada, la búsqueda de texto realiza una búsqueda OR para todas las palabras de la frase. Si desea buscar "patrones de diseño moderno", buscará documentos con las palabras clave moderno, diseño o patrones.
Ejemplo
>db.books.find({$text: {$search: "modern design patterns"}},{ subtitle: 1, description: 1 })
{
"_id" : ObjectId("602b098f3cb6144ada1c2ea1"),
"subtitle" : "A JavaScript and jQuery Developer's Guide",
"description" : "With Learning JavaScript Design Patterns, you'll learn how to write beautiful, structured, and maintainable JavaScript by applying classical and modern design patterns to the language. If you want to keep your code efficient, more manageable, and up-to-date with the latest best practices, this book is for you."
},
{
"_id" : ObjectId("602b09b93cb6144ada1c4bca"),
"subtitle" : "Robust Web Architecture with Node, HTML5, and Modern JS Libraries",
"description" : "Take advantage of JavaScript's power to build robust web-scale or enterprise applications that are easy to extend and maintain. By applying the design patterns outlined in this practical book, experienced JavaScript developers will learn how to write flexible and resilient code that's easier-yes, easier-to work with as your code base grows.",
},
{
"_id" : ObjectId("602b095c3cb6144ada1c1028"),
"subtitle" : "A Modern Introduction to Programming",
"description" : "JavaScript lies at the heart of almost every modern web application, from social apps to the newest browser-based games. Though simple for beginners to pick up and play with, JavaScript is a flexible, complex language that you can use to build full-scale applications."
}
>Si desea buscar frases exactas, como documentos con "patrones de diseño moderno", puede hacerlo especificando comillas dobles en el texto de búsqueda.
Ejemplo
>db.books.find({$text: {$search: "\"modern design patterns\""}},{ subtitle: 1, description: 1 })
{
"_id" : ObjectId("602b098f3cb6144ada1c2ea1"),
"subtitle" : "A JavaScript and jQuery Developer's Guide",
"description" : "With Learning JavaScript Design Patterns, you'll learn how to write beautiful, structured, and maintainable JavaScript by applying classical and modern design patterns to the language. If you want to keep your code efficient, more manageable, and up-to-date with the latest best practices, this book is for you."
}Negaciones
Si desea excluir los documentos que contienen una palabra en particular, puede utilizar una búsqueda de negación. Por ejemplo, si va a buscar todos los documentos con 'JavaScript' pero no con 'HTML5' o 'ECMAScript', puede buscar como se muestra en el siguiente ejemplo.
Ejemplo
>db.books.find({$text: {$search: "JavaScript -HTML5 -ECMAScript"}},{ subtitle: 1, description: 1 })
{
"_id" : ObjectId("602b098f3cb6144ada1c2ea1"),
"subtitle" : "A JavaScript and jQuery Developer's Guide",
"description" : "With Learning JavaScript Design Patterns, you'll learn how to write beautiful, structured, and maintainable JavaScript by applying classical and modern design patterns to the language. If you want to keep your code efficient, more manageable, and up-to-date with the latest best practices, this book is for you."
},
{
"_id" : ObjectId("602b09a83cb6144ada1c4973"),
"subtitle" : "An In-Depth Guide for Programmers",
"description" : "Like it or not, JavaScript is everywhere these days, from browser to server to mobile and now you, too, need to learn the language or dive deeper than you have. This concise book guides you into and through JavaScript, written by a veteran programmer who once found himself in the same position."
},
{
"_id" : ObjectId("602b095c3cb6144ada1c1028"),
"subtitle" : "A Modern Introduction to Programming",
"description" : "JavaScript lies at the heart of almost every modern web application, from social apps to the newest browser-based games. Though simple for beginners to pick up and play with, JavaScript is a flexible, complex language that you can use to build full-scale applications."
}Puntuación de búsqueda de texto
La búsqueda de texto proporciona una puntuación a cada documento que representa la relevancia del documento con la consulta de búsqueda. Esta puntuación se puede utilizar para ordenar todos los registros devueltos en el resultado de la búsqueda. Una puntuación más alta indicará una coincidencia más relevante.
Ejemplo
>db.books.find({$text: {$search: "JavaScript "}},{score: {$meta: "textScore"}, subtitle: 1, description: 1 }).sort({score:{$meta:"textScore"}})
{
"_id" : ObjectId("602b098f3cb6144ada1c2ea1"),
"subtitle" : "A JavaScript and jQuery Developer's Guide",
"description" : "With Learning JavaScript Design Patterns, you'll learn how to write beautiful, structured, and maintainable JavaScript by applying classical and modern design patterns to the language. If you want to keep your code efficient, more manageable, and up-to-date with the latest best practices, this book is for you.",
"score" : 1.43269230769231
},
{
"_id" : ObjectId("602b09cb3cb6144ada1c62fe"),
"subtitle" : "The Definitive Guide for JavaScript Developers",
"description" : "ECMAScript 6 represents the biggest update to the core of JavaScript in the history of the language. In Understanding ECMAScript 6, expert developer Nicholas C. Zakas provides a complete guide to the object types, syntax, and other exciting changes that ECMAScript 6 brings to JavaScript.",
"score" : 1.42672413793103
},
{
"_id" : ObjectId("602b09a83cb6144ada1c4973"),
"subtitle" : "An In-Depth Guide for Programmers",
"description" : "Like it or not, JavaScript is everywhere these days, from browser to server to mobile and now you, too, need to learn the language or dive deeper than you have. This concise book guides you into and through JavaScript, written by a veteran programmer who once found himself in the same position.",
"score" : 0.818181818181818
},
{
"_id" : ObjectId("602b095c3cb6144ada1c1028"),
"subtitle" : "A Modern Introduction to Programming",
"description" : "JavaScript lies at the heart of almost every modern web application, from social apps to the newest browser-based games. Though simple for beginners to pick up and play with, JavaScript is a flexible, complex language that you can use to build full-scale applications.",
"score" : 0.801724137931034
},
{
"_id" : ObjectId("602b09b93cb6144ada1c4bca"),
"subtitle" : "Robust Web Architecture with Node, HTML5, and Modern JS Libraries",
"description" : "Take advantage of JavaScript's power to build robust web-scale or enterprise applications that are easy to extend and maintain. By applying the design patterns outlined in this practical book, experienced JavaScript developers will learn how to write flexible and resilient code that's easier-yes, easier-to work with as your codebase grows.",
"score" : 0.792857142857143
}Palabras vacías
El operador $text filtra las palabras vacías específicas del idioma, como a, an, the y en inglés. La búsqueda a continuación no devolverá ningún documento en el resultado.
Ejemplo
>db.books.find({$text: {$search: "is"}},{subtitle: 1, description: 1 })
Fetched 0 record(s)Palabras derivadas
El operador $text coincide con la palabra derivada completa. Entonces, si algún campo del documento contiene la palabra aprender o aprender, una búsqueda del término aprender o aprender daría como resultado lo mismo.
Ejemplo
>db.books.find({$text: {$search: " learn"}},{subtitle: 1, description: 1 }) or >db.books.find({$text: {$search: " learning"}},{subtitle: 1, description: 1 })
{
"_id" : ObjectId("602b098f3cb6144ada1c2ea1"),
"subtitle" : "A JavaScript and jQuery Developer's Guide",
"description" : "With Learning JavaScript Design Patterns, you'll learn how to write beautiful, structured, and maintainable JavaScript by applying classical and modern design patterns to the language. If you want to keep your code efficient, more manageable, and up-to-date with the latest best practices, this book is for you."
},
{
"_id" : ObjectId("602b09a83cb6144ada1c4973"),
"subtitle" : "An In-Depth Guide for Programmers",
"description" : "Like it or not, JavaScript is everywhere these days, from browser to server to mobile and now you, too, need to learn the language or dive deeper than you have. This concise book guides you into and through JavaScript, written by a veteran programmer who once found himself in the same position."
},
{
"_id" : ObjectId("602b09b93cb6144ada1c4bca"),
"subtitle" : "Robust Web Architecture with Node, HTML5, and Modern JS Libraries",
"description" : "Take advantage of JavaScript's power to build robust web-scale or enterprise applications that are easy to extend and maintain. By applying the design patterns outlined in this practical book, experienced JavaScript developers will learn how to write flexible and resilient code that's easier-yes, easier-to work with as your codebase grows."
}Conclusión
Espero que hayas aprendido algo nuevo hoy. Aquí hay un artículo interesante sobre Self-Hosted MongoDB. También te invito a probar cosas por tu cuenta y compartir tu experiencia en la sección de comentarios. Además, si tiene algún problema con alguna de las definiciones anteriores, no dude en preguntarme en la sección de comentarios a continuación.
