bql_practical_examples.md

BQL Practical Examples

You may find a collection of examples on the examples folder. Each example file targets a particular BQL feature. The list shown below enumerates each of the example files with a brief description.

• First steps: This example shows how to create a graph, insert data, query the graph, and drop the graph. The query shows basic functionality on how how to express your graph query using graph clauses. The example shows how to search for particular patterns and extract IDs from graph nodes.

• Expressing graph patterns and grouping: This example shows how you can express complex graph queries by properly binding graph clauses together, OPTIONAL clauses included. You will also find examples on how to summary the results via the GROUP BY clause.

• Summarizing and sorting data queries across graphs: Sometimes you want to query data that is stored across multiple graphs. This example shows how you can express queries across multiple graphs, by simply listing them in the FROM clause, and summarize the results accordingly. It also shows how to sort the resulting tables using the ORDER BY clause. It is important to highlight that the BQL FROM clause does not express table joins, but the union of the specified graphs.

• Refining results: The HAVING clause is useful for filtering rows out from the resulting table. This file shows some simple examples of how you can easily achieve it by simply providing a boolean condition to the HAVING clause.

• Customizing data retrieval: To customize the data retrieval directly in the storage/driver level you can make use of the FILTER keyword, passing additional instructions to the driver to help it access and return a more fine-grained portion of the data stored, improving performance. This file, then, shows some simple examples of queries with FILTER clauses, with different FILTER functions being applied to illustrate how they can be useful.