This book is for practitioners and academics who have learned the conventions and rules of data modelling and are looking for a deeper understanding of the discipline. The coverage of theory includes a detailed review of the extensive literature on data modelling and logical database design, referencing nearly 500 publications, with a strong focus on their relevance to practice. The practice component incorporates the largest-ever study of data modelling practitioners, involving over 450 participants in interviews, surveys and data modelling tasks. The results challenge many long-standing held assumptions about data modelling and will be of interest to academics and practitioners alike. Graeme Simsion brings to the book the practical perspective and intellectual clarity that have made his "Data Modelling Essentials" a classic in the field. He begins with a question about the nature of data modelling (design or description), and uses it to illuminate such issues as the definition of data modelling, its philosophical underpinnings, inputs and deliverables, the necessary behaviours and skills, the role of creativity, product diversity, quality measures, personal styles, and the differences between experts and novices. "Data Modeling: Theory and Practice" is essential reading for anyone involved in data modelling practice, research, or teaching.