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Joe Celko s SQL for Smarties - Advanced SQL Programming P3

Joe Celko s SQL for Smarties - Advanced SQL Programming P3. In the SQL database community, Joe Celko is a well-known columnist and purveyor of valuable insights. In Joe Celko's SQL for Smarties: Advanced SQL Programming, he picks up where basic SQL training and experience leaves many database professionals and offers tips, techniques, and explanations that help readers extend their capabilities to top-tier SQL programming. Although Celko denies that the book is about database theory, he nevertheless alludes to theory often to buttress his practical points. This title is not for novices, as the author points out. Instead, its intended audience. | xx CONTENTS 25 Arrays in SQL 575 25.1 Arrays via Named Columns 576 25.2 Arrays via Subscript Columns 580 25.3 Matrix Operations in SQL 581 25.3.1 Matrix Equality 582 25.3.2 Matrix Addition 582 25.3.3 Matrix Multiplication 583 25.3.4 Other Matrix Operations 585 25.4 Flattening a Table into an Array 585 25.5 Comparing Arrays in Table Format 587 26 Set Operations 591 26.1 UNION and UNION ALL 592 26.1.1 Order of Execution 594 26.1.2 Mixed UNION and UNION ALL Operators 595 26.1.3 UNION of Columns from the Same Table 595 26.2 INTERSECT and EXCEPT 596 26.2.1 INTERSECT and EXCEPT without NULLs and Duplicates 599 26.2.2 INTERSECT and EXCEPT with NULLs and Duplicates 600 26.3 A Note on ALL and SELECT DISTINCT 601 26.4 Equality and Proper Subsets 602 27 Subsets 605 27.1 Every nth Item in a Table 605 27.2 Picking Random Rows from a Table 607 27.3 The CONTAINS Operators 612 27.3.1 Proper Subset Operators 612 27.3.2 Table Equality 613 27.4 Picking a Representative Subset 618 28 Trees and Hierarchies in SQL 623 28.1 Adjacency List Model 624 CONTENTS xxi 28.1.1 Complex Constraints 625 28.1.2 Procedural Traversal for Queries 627 28.1.3 Altering the Table 628 28.2 The Path Enumeration Model 628 28.2.1 Finding Subtrees and Nodes 629 28.2.2 Finding Levels and Subordinates 630 28.2.3 Deleting Nodes and Subtrees 630 28.2.4 Integrity Constraints 631 28.3 Nested Set Model of Hierarchies 631 28.3.1 The Counting Property 633 28.3.2 The Containment Property 634 28.3.3 Subordinates 635 28.3.4 Hierarchical Aggregations 636 28.3.5 Deleting Nodes and Subtrees 636 28.3.6 Converting Adjacency List to Nested Set Model 637 28.4 Other Models for Trees and Hierarchies 639 29 Temporal Queries 641 29.1 Temporal Math 642 29.2 Personal Calendars 643 29.3 Time Series 645 29.3.1 Gaps in a Time Series 645 29.3.2 Continuous Time Periods 648 29.3.3 Missing Times in Contiguous Events 652 29.3.4 Locating Dates 656 29.3.5 Temporal Starting and Ending Points 658 29.3.6 Average Wait Times 660 29.4 Julian Dates 661