Effective SQL: 61 Specific Ways to Write Better SQL, First Edition

Index

Symbols

& (ampersand) operator, concatenation symbol, 24, 249

+ (plus sign) operator, concatenation symbol, 24, 249

|| (vertical bars) operator, concatenation symbol, 24, 248–249

A

Absent data. See Null values.

Access

choosing a primary key, 88

Edit Relationships dialog box, 64

execution plans, 204–205, 212

ignoring columns, 87–88

importing data, 86–87

naming tables, 88

support for CTEs, 249

tools, 86–89

unpivoting sales data, 88–89

upsizing from, 63–64

Access, date and time

arithmetic operations, 303–304

data types, 303

functions, 304–305

Accumulating snapshot fact tables, 46

Adjacency list model, hierarchical data, 286–288

Age calculation, SQL code example, 113

Aggregation

counting items in a group, 156–159

distinct counts, 163–166