asmhatre
448c383879
Same Customer/Order/OrderItem domain modelled with Hibernate/Spring Data JPA and Spring Data JDBC side by side, both running through a shared StatementLoggingDataSource so SQL-statement counts are directly comparable. 11 tests, 11 captured transcripts, 6 doc chapters. Companion repo for the ankurm.com article on when to drop the ORM.
14 lines
690 B
Plaintext
14 lines
690 B
Plaintext
Scenario: findAll() for 3 orders (2 items each), then read .getItems().size()
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on each in a loop — the pattern that looks completely ordinary in a service
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method.
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1. select o1_0.id,o1_0.customer_id,o1_0.version from jpa_order o1_0
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2. select i1_0.order_id,i1_0.id,i1_0.quantity,i1_0.sku from jpa_order_item i1_0 where i1_0.order_id=?
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3. select i1_0.order_id,i1_0.id,i1_0.quantity,i1_0.sku from jpa_order_item i1_0 where i1_0.order_id=?
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4. select i1_0.order_id,i1_0.id,i1_0.quantity,i1_0.sku from jpa_order_item i1_0 where i1_0.order_id=?
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total statements: 4
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SELECT statements observed: 4 (1 for the orders themselves + 1 per order for
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its lazily-loaded items = N+1, here 1 + 3 = 4)
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