Practical sql: a beginner’s Guide to Storytelling with Data pdfdrive com
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ADVANCED QUERY TECHNIQUES Using Subqueries Filtering with Subqueries in a WHERE Clause Creating Derived Tables with Subqueries Joining Derived Tables Generating Columns with Subqueries Subquery Expressions Common Table Expressions Cross Tabulations Installing the crosstab() Function Tabulating Survey Results Tabulating City Temperature Readings Reclassifying Values with CASE Using CASE in a Common Table Expression Wrapping Up Try It Yourself 13 MINING TEXT TO FIND MEANINGFUL DATA Formatting Text Using String Functions Case Formatting Character Information Removing Characters Extracting and Replacing Characters Matching Text Patterns with Regular Expressions Regular Expression Notation Turning Text to Data with Regular Expression Functions Using Regular Expressions with WHERE Additional Regular Expression Functions Full Text Search in PostgreSQL Text Search Data Types Creating a Table for Full Text Search Searching Speech Text Ranking Query Matches by Relevance Wrapping Up Try It Yourself 14 ANALYZING SPATIAL DATA WITH POSTGIS Installing PostGIS and Creating a Spatial Database The Building Blocks of Spatial Data Two-Dimensional Geometries Well-Known Text Formats A Note on Coordinate Systems Spatial Reference System Identifier PostGIS Data Types Creating Spatial Objects with PostGIS Functions Creating a Geometry Type from Well-Known Text Creating a Geography Type from Well-Known Text Point Functions LineString Functions Polygon Functions Analyzing Farmers’ Markets Data Creating and Filling a Geography Column Adding a GiST Index Finding Geographies Within a Given Distance Finding the Distance Between Geographies Working with Census Shapefiles Contents of a Shapefile Loading Shapefiles via the GUI Tool Exploring the Census 2010 Counties Shapefile Performing Spatial Joins Exploring Roads and Waterways Data Joining the Census Roads and Water Tables Finding the Location Where Objects Intersect Wrapping Up Try It Yourself tải về 5.77 Mb. Chia sẻ với bạn bè của bạn:
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