# Order of operations

Published articles for Order of operations.

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## How to Filter a SQL Nested Collection by a Value

DevFeed: [How to Filter a SQL Nested Collection by a Value](<https://devfeed.tech/articles/how-to-filter-a-sql-nested-collection-by-a-value-28940.md>)

Original publisher: [Read original article](<https://blog.jooq.org/how-to-filter-a-sql-nested-collection-by-a-value/>)

Author: lukaseder

Published: 2022-06-10T14:32:38Z

Content type: tutorial

Language: en

Sources: [jOOQ](<https://devfeed.tech/sources/jooq.md>)

Topics: [SQL](<https://devfeed.tech/topics/sql.md>), [PostgreSQL](<https://devfeed.tech/topics/postgresql.md>), [Stack Overflow](<https://devfeed.tech/topics/stackoverflow.md>)

Tags: [array](<https://devfeed.tech/tags/array.md>), [array-agg](<https://devfeed.tech/tags/array-agg.md>), [derived-table](<https://devfeed.tech/tags/derived-table.md>), [filter](<https://devfeed.tech/tags/filter.md>), [how-to](<https://devfeed.tech/tags/how-to.md>), [jooq](<https://devfeed.tech/tags/jooq.md>), [multiset](<https://devfeed.tech/tags/multiset.md>), [multiset-agg](<https://devfeed.tech/tags/multiset-agg.md>), [nested-collections](<https://devfeed.tech/tags/nested-collections.md>), [order-of-operations](<https://devfeed.tech/tags/order-of-operations.md>), [postgresql](<https://devfeed.tech/tags/postgresql.md>), [predicate](<https://devfeed.tech/tags/predicate.md>), [sql](<https://devfeed.tech/tags/sql.md>)

### AI overview

This tutorial explains how to filter SQL nested collections by a value. It compares filtering arrays through a derived table with using PostgreSQL's ARRAY_AGG and group filtering, then shows a jOOQ version intended to work across supported relational database systems.

### Source excerpt

I stumbled upon a very interesting question on Stack Overflow about how to use jOOQ's MULTISET operator to nest a collection, and then filter the result by whether that nested collection contains a value. The question is jOOQ specific, but imagine, you have a query that nests collections using JSON in PostgreSQL. Assuming, as always, ... Continue reading How to Filter a SQL Nested Collection by a Value ->

## Changing SELECT .. FROM Into FROM .. SELECT Does Not "Fix" SQL

DevFeed: [Changing SELECT .. FROM Into FROM .. SELECT Does Not "Fix" SQL](<https://devfeed.tech/articles/changing-select-from-into-from-select-does-not-fix-sql-28934.md>)

Original publisher: [Read original article](<https://blog.jooq.org/changing-select-from-into-from-select-does-not-fix-sql/>)

Author: lukaseder

Published: 2022-05-31T08:39:55Z

Content type: opinion

Language: en

Sources: [jOOQ](<https://devfeed.tech/sources/jooq.md>)

Topics: [SQL](<https://devfeed.tech/topics/sql.md>), [ordering](<https://devfeed.tech/topics/ordering.md>), [Databases](<https://devfeed.tech/topics/databases.md>), [Programming](<https://devfeed.tech/topics/programming.md>)

Tags: [jooq](<https://devfeed.tech/tags/jooq.md>), [jooq-development](<https://devfeed.tech/tags/jooq-development.md>), [operations](<https://devfeed.tech/tags/operations.md>), [order-of-operations](<https://devfeed.tech/tags/order-of-operations.md>), [rdbms](<https://devfeed.tech/tags/rdbms.md>), [sql](<https://devfeed.tech/tags/sql.md>), [sql-syntax](<https://devfeed.tech/tags/sql-syntax.md>), [syntax](<https://devfeed.tech/tags/syntax.md>)

### AI overview

The article examines the difference between SQL's lexical order, such as SELECT .. FROM, and its logical order of operations, such as FROM .. SELECT. It argues that changing the syntax would improve logical consistency but would not fully fix SQL, and discusses jOOQ's support for alternative forms and variations across database systems.

### Source excerpt

Every now and then, I see folks lament the SQL syntax's peculiar disconnect between the lexical order of operations (SELECT .. FROM) the logical order of operations (FROM .. SELECT) Most recently here in a Youtube comment reply to a recent jOOQ/kotlin talk. Let's look at why jOOQ didn't fall into this trap of trying ... Continue reading Changing SELECT .. FROM Into FROM .. SELECT Does Not "Fix" SQL ->

## Effective Kotlin Item 54: Prefer Sequences for big collections with more than one processing step

DevFeed: [Effective Kotlin Item 54: Prefer Sequences for big collections with more than one processing step](<https://devfeed.tech/articles/effective-kotlin-item-54-prefer-sequences-for-big-collections-with-more-than-one-processing-step-39290.md>)

Original publisher: [Read original article](<https://kt.academy/article/ek-sequence>)

Published: 2021-09-20T00:00:00Z

Content type: tutorial

Language: en

Sources: [Kt. Academy](<https://devfeed.tech/sources/kt-academy.md>)

Topics: [Sequences](<https://devfeed.tech/topics/sequences.md>), [Collections](<https://devfeed.tech/topics/collections.md>), [.NET](<https://devfeed.tech/topics/net.md>)

Tags: [collections](<https://devfeed.tech/tags/collections.md>), [kotlin](<https://devfeed.tech/tags/kotlin.md>), [lazy](<https://devfeed.tech/tags/lazy.md>), [order-of-operations](<https://devfeed.tech/tags/order-of-operations.md>), [sequences](<https://devfeed.tech/tags/sequences.md>), [workshop-learning-programming](<https://devfeed.tech/tags/workshop-learning-programming.md>)

### AI overview

This article explains the difference between Kotlin collection and sequence processing. Sequences are lazy: intermediate operations build a processing chain, and calculations occur during terminal operations. The article discusses their element-by-element ordering, reduced processing work, support for infinite sequences, and avoidance of intermediate collections.

### Source excerpt

What the difference between list and sequence processing is, and when each should be preferred.