mirror of https://gitee.com/bigwinds/arangodb
30 lines
1.6 KiB
Plaintext
30 lines
1.6 KiB
Plaintext
!CHAPTER Introduction
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The ArangoDB query language (AQL) can be used to retrieve and modify data that
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are stored in ArangoDB. The general workflow when executing a query is as follows:
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- A client application ships an AQL query to the ArangoDB server. The query text
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contains everything ArangoDB needs to compile the result set
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- ArangoDB will parse the query, execute it and compile the results. If the
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query is invalid or cannot be executed, the server will return an error that
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the client can process and react to. If the query can be executed
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successfully, the server will return the query results (if any) to the client
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AQL is mainly a declarative language, meaning that in a query it is expressed
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what result should be achieved and not how. AQL aims to be human- readable and
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therefore uses keywords from the English language. Another design goal of AQL
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was client independency, meaning that the language and syntax are the same for
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all clients, no matter what programming language the clients might use. Further
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design goals of AQL were the support of complex query patterns and the different
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data models ArangoDB offers.
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In its purpose, AQL is similar to the Structured Query Language (SQL). AQL supports
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reading and modifying collection data, but it doesn't support data-definition
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operations such as creating and dropping databases, collections and indexes.
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The syntax of AQL queries is different to SQL, even if some keywords overlap.
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Nevertheless, AQL should be easy to understand for anyone with an SQL background.
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For some example queries, please refer to the page [AQL Examples](../AqlExamples/README.md).
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