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--- tutorial:poly_db_querying [2017/07/26 14:28] – paffenholz
+++ tutorial:poly_db_querying [2018/02/10 11:38] (current) – deleted after merging into doku.php/tutorial/poly_db_tutorial oroehrig
@@ Line 1: / Line 1: @@
-==== Querying the Database ====
-There are three commands that can be used to query the database:
-   * ''db_query'': Obtain one or more objects that satisfy a query
-   * ''db_count'': Count objects that satisfy a query
-   * ''db_ids'': Obtain ''id''s of objects that satisfy a query
-== Queries ==
-Queries are given as perl hashes. In its most basic form a query has the form
-   { "PROPERTY1" => <value1>, "PROPERTY2" => <value2>, ... }
-for example
-   { "DIM" => 3, "N_VERTICES" => 7 }
-Note that the database is pretty strict with types, so strings always need to be quoted, while integers should not be. The following would fail:
-   { "DIM" => "3" }
-You can query elements in an array with their index, e.g.
-   { "F_VECTOR.1" => 12 }
-gives polytopes with 5 edges (the entry at position one of the f-vector.
-== Obtain Objects that Satisfy a Query ==
-== Count Objects that Satisfy a Query ==
-== Obtain Object ''ID''s that Satisfy a Query ==