The Mother of All Query Languages: SQL in Modern Times

Transcription

1 The Mother of All Query Languages: SQL in

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3 SQL-92 Tied to the Relational Idea Relational Data Model Atomic types (domain) Atom image:

4 SQL-92 Tied to the Relational Idea Relational Data Model Atomic types (domain) A B C

5 SQL-92 Tied to the Relational Idea Relational Data Model Atomic types (domain) Schema independent of processing purposes Normalization A B C C D B E

6 SQL-92 Tied to the Relational Idea Relational Data Model Atomic types (domain) Schema independent of processing purposes Normalization Relational Operations Transform data for each particular processing purposes JOIN, UNION, nesting, A B C C D B E A B C D E

7 SQL-92 Tied to the Relational Idea Relational Data Model Atomic types (domain) Schema independent of processing purposes Normalization Relational Operations Transform data for each particular processing purposes JOIN, UNION, nesting, A B C C D B E A B C D E A B E

8 SQL-92 Tied to the Relational Idea Relational Data Model Atomic types (domain) Schema independent of processing purposes Normalization Relational Operations Transform data for each particular processing purposes JOIN, UNION, nesting, A B C C D B E A B C D E C D E A B E

9 SQL-92 Tied to the Relational Idea Relational Data Model Atomic types (domain) Schema independent of processing purposes Normalization Relational Operations Transform data for each particular processing purposes JOIN, UNION, nesting, A B C C D B E A B C D E A B E C D E

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12 SQL:1999 Escaping the Relational Cage To say that these SQL:1999 extensions are mere extended interpretations of the relational data model is like saying that an intercontinental ballistic missile is merely an extended interpretation of a spear. With SQL/99 you can get the best of both worlds and of course, you can get the worst of both worlds. It s up to the database practitioners to do the right thing.

13 SQL:1999 Escaping the Relational Cage Relational Model? I was as confused as anyone else? Date on Database: Writings Chris Date

14 SQL:1999 Escaping the Relational Cage Relational Model? I was as confused as anyone else By the early 1990s, however, I d seen the light? Domains Can Contain Anything! Date on Database: Writings Chris Date

15 SQL:1999 Escaping the Relational Cage Relational Model? Introduced rich types I was as confused as anyone else By the early 1990s, however, I d seen the light? Domains Can Contain Anything! Date on Database: Writings Chris Date

16 SQL:1999 Escaping the Relational Cage Relational Model? Introduced rich types arrays A B [, ] [ ] [] I was as confused as anyone else By the early 1990s, however, I d seen the light? Domains Can Contain Anything! Date on Database: Writings Chris Date

17 SQL:1999 Escaping the Relational Cage Relational Model? A B C Introduced rich types arrays Nested tables (multiset) [, ] [ ] C D C D [] C D I was as confused as anyone else By the early 1990s, however, I d seen the light? Domains Can Contain Anything! Date on Database: Writings Chris Date

18 SQL:1999 Escaping the Relational Cage Relational Model? A B C D Introduced rich types arrays Nested tables (multiset) [, ] [ ] C D C D {x:, y: } {x:, y: } composite types (objects) [] C D {x:, y: } I was as confused as anyone else By the early 1990s, however, I d seen the light? Domains Can Contain Anything! Date on Database: Writings Chris Date

19 SQL:1999 Escaping the Relational Cage Relational Model? Introduced rich types arrays Nested tables (multiset) composite types (objects) Non-Relational Operations Introduced recursive queries that process their own output Transitive closure I was as confused as anyone else By the early 1990s, however, I d seen the light? Domains Can Contain Anything! Date on Database: Writings Chris Date

20 SQL:1999 Recursion

21 SQL:1999 Recursion

22 SQL:1999 Recursion

23 SQL:1999 Recursion SELECT t.id, t.parent FROM t WHERE t.id =? UNION ALL SELECT t.id, t.parent FROM t WHERE t.parent =?

24 SQL:1999 Recursion SELECT t.id, t.parent FROM t WHERE t.id =? UNION ALL SELECT t.id, t.parent FROM t WHERE t.parent =?

25 SQL:1999 Recursion SELECT t.id, t.parent FROM t WHERE t.id =? UNION ALL SELECT t.id, t.parent FROM t WHERE t.parent =?

26 SQL:1999 Recursion WITH RECURSIVE prev (id, parent) AS ( SELECT t.id, t.parent FROM t WHERE t.id =? UNION ALL SELECT t.id, t.parent FROM t JOIN prev ON t.parent = prev.id ) SELECT * FROM prev

27 SQL:1999 Recursion MariaDB 8.0 MySQL 8.4 PostgreSQL [0] SQLite 7.0 DB2 LUW 11gR2 Oracle [0] Only for top-level SELECT statements 2005 SQL Server

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29 SQL:2016 JSON

30 SQL:2016 JSON [ { "id": 42, "a1": "foo" id a1 }, 42 foo { } "id": 43, "a1": "bar" 43 bar ]

31 SQL:2016 JSON SELECT * FROM tbl, JSON_TABLE ( jsoncol, '$[*]' COLUMNS [ ] { "id": 42, "a1": "foo" }, { "id": 43, "a1": "bar" } ( id INT PATH '$.id', a1 VARCHAR( ) PATH '$.a1' id a1 ) ) r 42 foo 43 bar

32 SQL:2016 JSON SELECT * SQL/JSON Path [ { FROM tbl, JSON_TABLE Query language to select elements from "id": 42, "a1": "foo" }, ( jsoncol a JSON document { "id": 43,, '$[*]' Defined in the SQL standard } "a1": "bar" COLUMNS ] ( id INT PATH '$.id', a1 VARCHAR( ) PATH '$.a1' id a1 ) ) r 42 foo 43 bar

33 SQL:2016 JSON SELECT * SQL/JSON Path [ { FROM tbl, JSON_TABLE Query language to select elements from "id": 42, "a1": "foo" }, ( jsoncol a JSON document { "id": 43,, '$[*]' Defined in the SQL standard } "a1": "bar" COLUMNS ] ( id INT PATH '$.id', a1 VARCHAR( ) PATH '$.a1' id a1 ) ) r 42 foo 43 bar

34 SQL:2016 JSON MariaDB 8.0 MySQL PostgreSQL SQLite DB2 LUW 12cR1 Oracle SQL Server

35 A lot has happened since SQL-92 SQL has evolved beyond the relational idea If you use SQL for CRUD operations only, you are doing it wrong