One of the main features of ORMs is M as in Mapping. Libraries like jOOQ help auto-mapping flat or nested database records onto Java classes that have the same structure as the SQL result set. The following has always been possible in jOOQ, assuming PostgreSQL's INFORMATION_SCHEMA (using the generated code from the jOOQ-meta module): class … Continue reading Nesting Collections With jOOQ 3.14’s SQL/XML or SQL/JSON support
Tag: Nested collections
How to Write Multiset Conditions With Oracle VARRAY Types
Oracle is one of the few databases that implements the SQL standard ORDBMS extensions, which essentially allow for nested collections. Other databases that have these features to some extent are CUBRID, Informix, PostgreSQL. Oracle has two types of nested collections: -- Nested tables CREATE TYPE t1 AS TABLE OF VARCHAR2(10); / -- Varrays CREATE TYPE … Continue reading How to Write Multiset Conditions With Oracle VARRAY Types
Beautiful SQL: Lateral Unnesting of Array Columns
Sometimes, SQL can just be so beautiful. One of the less mainstream features in SQL is the array type (or nested collections). In fact, it's so not mainstream that only 2 major databases actually support it: Oracle and PostgreSQL (and HSQLDB and H2 in the Java ecosystem). In PostgreSQL, you can write: CREATE TABLE blogs … Continue reading Beautiful SQL: Lateral Unnesting of Array Columns