CONTENTS 5.4 Caching theory and practice 175 strategies and scopes 176.The Hibernale cach 179Caching in practice 185 5.5 Summary 194 Advanced mapping concepts 195 6.1 Understanding the Hibernate type system 196 Buil-in mapping types 198 Using mapping types 200 6.2 Mapping collections of value types 211 Sets,bags,lists,and maps 211 6.3 Mapping entity associations 220 Oneto-one associations 220.Many-to-many associations 225 6.4 Mapping polymorphic associations 234 Polymorphic many-to-one associations 234Polymorphi collections 236.Polymorphic associations and table-per- concrete-class 237 6.5 Summary 239 Retrieving objects efficiently 241 7.1 Executing queries 243 The query interfaces 243.Binding parameters 245 Using named queries 249 7.2 Basic queries for objects 250 The simplest quer町y250·Using aliases251·Polymorphic queries 251.Restriction 252.Comparison operators 253 String matching 255.Logical operators 256.Ordering query results 257 7.3 Joining associations 258 Hibernate join options 259.Fetching associations 260 Using aliases with joins 262.Using implicit joins 265 Theta-style joins 267.Comparing identifiers 268 7.4 Writing report queries 269 Projection 270.Using aggregation 272.Grouping 273 Restricting groups with having 274.Improving performance with report queries 275 viii CONTENTS 5.4 Caching theory and practice 175 Caching strategies and scopes 176 ■ The Hibernate cache architecture 179 ■ Caching in practice 185 5.5 Summary 194 6 Advanced mapping concepts 195 6.1 Understanding the Hibernate type system 196 Built-in mapping types 198 ■ Using mapping types 200 6.2 Mapping collections of value types 211 Sets, bags, lists, and maps 211 6.3 Mapping entity associations 220 One-to-one associations 220 ■ Many-to-many associations 225 6.4 Mapping polymorphic associations 234 Polymorphic many-to-one associations 234 ■ Polymorphic collections 236 ■ Polymorphic associations and table-per￾concrete-class 237 6.5 Summary 239 7 Retrieving objects efficiently 241 7.1 Executing queries 243 The query interfaces 243 ■ Binding parameters 245 Using named queries 249 7.2 Basic queries for objects 250 The simplest query 250 ■ Using aliases 251 ■ Polymorphic queries 251 ■ Restriction 252 ■ Comparison operators 253 String matching 255 ■ Logical operators 256 ■ Ordering query results 257 7.3 Joining associations 258 Hibernate join options 259 ■ Fetching associations 260 Using aliases with joins 262 ■ Using implicit joins 265 Theta-style joins 267 ■ Comparing identifiers 268 7.4 Writing report queries 269 Projection 270 ■ Using aggregation 272 ■ Grouping 273 Restricting groups with having 274 ■ Improving performance with report queries 275 Licensed to Jose Carlos Romero Figueroa <jose.romero@galicia.seresco.es>