Learn DocumentDB SQL

Documentdb is microsoft’s newest nosql record database platform that runs on azure. in this tutorial, we can learn all about querying files using the special version of square supported via documentdb.

NOSql file database
documentdb is microsoft’s most up-to-date nosql document database, but, while we say nosql record database, what precisely can we mean by means of nosql, and file database?

– sql approach established query language that is a traditional question language of relational databases. square is frequently equated with relational databases.

– it is truly greater helpful to think about a nosql database as a non-relational database, so nosql certainly manner non-relational.

there are unique varieties of nosql databases which consist of key fee shops which include −

-azure table storage
-column-based totally stores, like cassandra
-graph databases, like neo4
-report databases, like mongodb and azure documentdb

why square syntax?
this could sound strange at the beginning, however in documentdb that is a nosql database, we question the usage of square. as noted above, that is a unique model of square rooted in json and javascript semantics.

square is only a language, but it’s also a completely popular language it’s wealthy and expressive. for that reason, it truly looks as if a great concept to use some dialect of sq. rather than come up with an entire new way of expressing queries that we’d need to research if you wanted to get files out of your database.

– sql is designed for relational databases, and documentdb is a non-relational report database. documentdb crew has definitely tailored the sql syntax for the non-relational international of file databases, and this is what is meant through rooting square in json and javascript.

– the language nevertheless reads as familiar sq., however the semantics are all based on schemafree json documents as opposed to relational tables. in documentdb, we will be working with javascript records kinds rather than sq. statistics sorts. we can be acquainted with select, from, where, and so forth, but with javascript sorts, which can be restrained to numbers and strings, gadgets, arrays, boolean, and null are far fewer than the wide range of sq. data sorts.

– similarly, expressions are evaluated as javascript expressions rather than some form of t-sq.. as an instance, in a world of denormalized statistics, we’re not handling the rows and columns, but schema-unfastened files with hierarchal structures that include nested arrays and gadgets.

how does square paintings?
the documentdb team has replied this query in numerous revolutionary methods. few of them are listed as follows −

first, assuming you’ve got now not changed the default behavior to automatically index each belongings in a report, you may use dotted notation on your queries to navigate a route to any belongings irrespective of how deeply nested it is able to be in the record.

you could also perform an intra-file be part of in which nested array factors are joined with their figure element inside a record in a way very much like the way a join is done among tables in the relational global.

your queries can go back files from the database as it’s miles, or you could project any custom json form you want based totally on as a whole lot or as little of the report records which you need.

sql in documentdb helps the various not unusual operators consisting of −

– arithmetic and bitwise operations

– and and or common sense

– equality and variety comparisons

– string concatenation

the question language also supports a bunch of built-in functions.

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