Churcher Beginning SQL Queries

From Novice to Professional
1. ed
ISBN: 978-1-4302-0550-0
Verlag: Apress
Format: PDF
Kopierschutz: 1 - PDF Watermark

E-Book, Englisch, 240 Seiten

Beginning Queries with SQL is a friendly and easily read guide to writing queries with the all-important - in the database world - SQL language. Anyone who does any work at all with databases needs to know something of SQL, and that is evidenced by the strong sales of such books as Learning SQL (O'Reilly) and SQL Queries for Mere Mortals (Pearson). Beginning Queries with SQL is written by the author of Beginning Database Design, an author who is garnering great reviews on Amazon due to the clarity and succinctness of her writing.

Clare Churcher is currently a senior lecturer in the Department of Applied Computing at Lincoln University, New Zealand. She holds a degree in physics with first class honors and completed a Ph.D in physics at the University of Canterbury, New Zealand. She has done postdoctoral research in the Cavendish Laboratory at the University of Cambridge, England. Clare s research interests are in the management and visualization of data especially for scientific research. She has a background in database design, and has taught programming, analysis and design of information systems, and database management at undergraduate level, as well as software engineering and scientific visualization at post graduate level.

Autoren/Hrsg.

Churcher, Clare

Inhaltsverzeichnis

1;Contents at a Glance;5
2;Contents;6
3;About the Author;12
4;About the Technical Reviewer;13
5;Acknowledgments;14
6;Introduction;15
7;Relational Database Overview;17
7.1;What Is a Relational Database?;17
7.2;Retrieving Information from a Database;26
7.3;Summary;31
8;Simple Queries on One Table;32
8.1;Retrieving a Subset of Rows;35
8.2;Retrieving a Subset of Columns;37
8.3;Using Aliases;38
8.4;Combining Subsets of Rows and Columns;39
8.5;Saving Queries;40
8.6;Specifying Conditions for Selecting Rows;40
8.7;Dealing with Nulls;44
8.8;Managing Duplicates;47
8.9;Ordering Output;50
8.10;Performing Simple Counts;50
8.11;Avoiding Common Mistakes;51
8.12;Summary;54
9;A First Look at Joins;56
9.1;Joins in Relational Algebra;56
9.2;Joins in Relational Calculus;60
9.3;Extending Join Queries;61
9.4;Other Types of Joins;69
9.5;Summary;73
10;Nested Queries;75
10.1;IN Keyword;75
10.2;Using IN with a Nested Query;76
10.3;Being Careful with NOT and <>;78
10.4;EXISTS Keyword;81
10.5;Different Types of Nesting;83
10.6;Using Nested Queries for Updating;87
10.7;Summary;89
11;Self Joins;90
11.1;Self Relationships;90
11.2;Questions Involving “ Both”;101
11.3;Summary;105
12;More Than One Relationship Between Tables;107
12.1;Representing Multiple Relationships Between Tables;107
12.2;Algebra Approach to Two Relationships Between Tables;109
12.3;Calculus Approach to Two Relationships Between Tables;113
12.4;Business Rules;114
12.5;Summary;117
13;Set Operations;118
13.1;Overview of Basic Set Operations;119
13.2;Union- Compatible Tables;120
13.3;Union;122
13.4;Intersection;128
13.5;Difference;134
13.6;Division;138
13.7;Summary;143
14;Aggregate Operations;144
14.1;Simple Aggregates;144
14.2;Grouping;150
14.3;Nested Queries and Aggregates;158
14.4;Summary;161
15;Efficiency Considerations;163
15.1;Indexes;163
15.2;Query Optimizer;171
15.3;Summary;177
16;How to Approach a Query;178
16.1;Understanding the Data;178
16.2;Big Picture Approach;183
16.3;Spotting Key Words in Questions;188
16.4;No Idea Where to Start?;192
16.5;Checking Queries;195
16.6;Summary;197
17;Common Problems;199
17.1;Poor Database Design;199
17.2;Problems with Data Values;205
17.3;Diagnosing Problems;208
17.4;Common Symptoms;210
17.5;Common Typos and Syntax Problems;215
17.6;Summary;216
18;Sample Database;217
19;Index;219