Practical sql: a beginner’s Guide to Storytelling with Data pdfdrive com
tải về 5.77 Mb. Chế độ xem pdf
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| CONTENTS IN DETAIL
FOREWORD by Sarah Frostenson ACKNOWLEDGMENTS INTRODUCTION What Is SQL? Why Use SQL? About This Book Using the Book’s Code Examples Using PostgreSQL Installing PostgreSQL Working with pgAdmin Alternatives to pgAdmin Wrapping Up 1 CREATING YOUR FIRST DATABASE AND TABLE Creating a Database Executing SQL in pgAdmin Connecting to the Analysis Database Creating a Table The CREATE TABLE Statement Making the teachers Table Inserting Rows into a Table The INSERT Statement Viewing the Data When Code Goes Bad Formatting SQL for Readability Wrapping Up Try It Yourself 2 BEGINNING DATA EXPLORATION WITH SELECT Basic SELECT Syntax Querying a Subset of Columns Using DISTINCT to Find Unique Values Sorting Data with ORDER BY Filtering Rows with WHERE Using LIKE and ILIKE with WHERE Combining Operators with AND and OR Putting It All Together Wrapping Up Try It Yourself 3 UNDERSTANDING DATA TYPES Characters Numbers Integers Auto-Incrementing Integers Decimal Numbers Choosing Your Number Data Type Dates and Times Using the interval Data Type in Calculations Miscellaneous Types Transforming Values from One Type to Another with CAST CAST Shortcut Notation Wrapping Up Try It Yourself 4 IMPORTING AND EXPORTING DATA Working with Delimited Text Files Quoting Columns that Contain Delimiters Handling Header Rows Using COPY to Import Data Importing Census Data Describing Counties Creating the us_counties_2010 Table Census Columns and Data Types Performing the Census Import with COPY Importing a Subset of Columns with COPY Adding a Default Value to a Column During Import Using COPY to Export Data Exporting All Data Exporting Particular Columns Exporting Query Results Importing and Exporting Through pgAdmin Wrapping Up Try It Yourself tải về 5.77 Mb. Chia sẻ với bạn bè của bạn:
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