Spatial Data SQL Queries Training Course

Participants can structure readable SQL statements that support later spatial analysis.

• SELECT, WHERE and ORDER BY patterns for geographic attribute filtering
• INNER, LEFT and CROSS joins applied to location reference tables
• GROUP BY and HAVING clauses for geographic reporting measures
• Common table expressions used to stage multi-step spatial queries
• CASE expressions for classifying records by operational location rules
• Null handling with COALESCE, NULLIF and three-valued SQL logic

Participants can select suitable spatial types and coordinate reference systems for stated analysis requirements.

• Point, line, polygon and multipolygon geometry types in PostGIS
• Geometry versus geography types for local and global measurements
• EPSG codes, SRIDs and coordinate reference system metadata
• Choosing projected coordinate systems for area and distance calculations
• ST_SetSRID, ST_Transform and transformation error diagnosis methods
• Axis order, longitude latitude order and coordinate precision controls

Participants can load spatial data into structured tables with appropriate constraints and metadata.

• PostGIS table design using geometry columns and dimensional constraints
• Primary keys, foreign keys and lookup tables for geographic datasets
• Importing shapefiles, GeoJSON and CSV coordinates with GDAL tools
• Well-Known Text and Well-Known Binary geometry encoding formats
• ST_GeomFromText and ST_MakePoint for controlled geometry creation
• Metadata records for lineage, currency, licence and coordinate reference systems

Participants can select records accurately using topological and distance-based spatial predicates.

• ST_Intersects for identifying features with shared spatial extent
• ST_Within and ST_Contains for containment-based record selection
• ST_Touches, ST_Crosses and ST_Overlaps for boundary relationships
• ST_DWithin for indexed proximity searches using defined distance thresholds
• Bounding-box operators for early candidate filtering and index use
• Testing predicate direction when points, lines and polygons interact

Participants can create derived geometries and calculate defensible spatial measures.

• ST_Buffer parameters for distance zones, joins and service catchments
• ST_Distance and ST_Length with suitable coordinate system selection
• ST_Area calculations, units conversion and polygon measurement checks
• ST_Centroid, ST_PointOnSurface and representative location selection
• ST_Envelope and ST_Extent for spatial coverage and data footprint summaries
• ST_Union and ST_Collect for combining related geographic features

Participants can join datasets by location and produce overlay-derived business measures.

• Spatial join patterns combining attributes through ST_Intersects predicates
• Point-in-polygon joins for customer, incident and asset allocation
• ST_Intersection for extracting overlapping roads, zones and land parcels
• ST_Difference for identifying excluded areas and residual territories
• Many-to-many spatial joins and duplicate result management techniques
• Area-weighted allocation methods for intersecting administrative boundary datasets

Participants can answer nearest-feature and travel-independent proximity questions efficiently.

• K-nearest-neighbour operators for ordered nearest asset searches
• LATERAL joins for nearest facility lookup per source record
• ST_DWithin prefilters combined with exact distance measurements
• Ranking nearest locations using window functions and distance ordering
• Distance bands for service coverage, exposure and response analysis
• Planar versus geodesic distance choices for operational query requirements

Participants can summarise location-based activity into areas, grids and management zones.

• Counts and sums grouped by administrative areas through spatial joins
• ST_ClusterDBSCAN for density-based clustering of point event datasets
• Grid generation with ST_SquareGrid for consistent geographic aggregation
• Rate calculations using population, area and denominator reference datasets
• Percentages and suppression rules for sensitive small-area reporting
• Materialized views for recurring geographic summary tables and dashboards

Participants can build spatial indexes and improve slow queries using execution-plan evidence.

• GiST indexes for geometry columns and bounding-box search operations
• SP-GiST index use cases for selected spatial data distributions
• EXPLAIN and EXPLAIN ANALYZE for spatial query-plan interpretation
• Index-supported predicates versus functions that prevent index usage
• Statistics maintenance with ANALYZE after major spatial data loads
• Query rewrites using candidate filters and staged exact calculations

Participants can inspect and query raster data alongside vector features for location-based analysis.

• Raster bands, pixels, nodata values and spatial alignment concepts
• ST_Value for retrieving raster values at specified point locations
• ST_Clip for limiting raster processing to areas of interest
• ST_SummaryStats for raster distribution measures within selected areas
• Vector-raster overlay patterns for elevation, flood and land-cover analysis
• Raster storage choices, tiling and performance implications for queries

Participants can identify and correct common spatial data defects before analysis or publication.

• ST_IsValid and ST_IsValidReason for geometry defect identification
• ST_MakeValid approaches for self-intersections and invalid polygon rings
• Duplicate geometry detection using equality and proximity comparison methods
• Topology rules for gaps, overlaps, dangles and boundary consistency
• Precision reduction methods for coordinate noise and storage control
• Quality-control queries documented with exceptions, owners and remediation actions

Participants can query changing locations, boundaries and asset states across defined time periods.

• Valid time, transaction time and effective-dated spatial record concepts
• Range types and exclusion constraints for non-overlapping asset histories
• Temporal joins between events, boundaries and operational service zones
• Versioned geometry records with audit columns and change reason codes
• Point-in-time queries using effective dates and spatial predicates
• Archiving strategies for superseded boundaries, routes and asset locations

Participants can build maintainable multi-stage spatial analyses using advanced SQL structures.

• Recursive common table expressions for connected network-like relationships
• Window functions for spatial ranking, sequencing and rolling measures
• LATERAL subqueries for per-feature derived spatial calculations
• SQL functions for reusable parameterised spatial query logic
• Temporary tables versus common table expressions for complex processing
• Transaction control for safe loading, correction and analysis workflows

Participants can prepare secure, map-ready outputs for web, reporting and GIS consumers.

• GeoJSON output using ST_AsGeoJSON and feature property construction
• Database views for controlled access to map-ready result datasets
• Vector tile concepts and ST_AsMVT query preparation methods
• Simplification with ST_SimplifyPreserveTopology for web display performance
• Stable identifiers, display fields and geometry naming conventions
• Output validation against source records, maps and business definitions

Participants can apply database controls appropriate to sensitive and operational spatial data.

• Role-based permissions for spatial tables, views and database functions
• Row-level security patterns for territory, region and client restrictions
• Sensitive location handling through masking, aggregation and access controls
• Metadata requirements for source authority, licence and update frequency
• Audit logging for edits to regulated assets and geographic boundaries
• Release checklists for spatial schema changes and published query views

Participants can move data and query logic between common GIS and database environments.

• PostGIS, SQL Server and Oracle Spatial function mapping considerations
• OGC Simple Features SQL interoperability limits and vendor extensions
• QGIS database connections for inspecting query outputs and source tables
• GDAL and OGR conversions between file formats and database layers
• GeoJSON, GeoPackage and shapefile strengths, constraints and field limitations
• Portable SQL design choices for multi-platform spatial data estates

Participants can translate operational questions into testable spatial SQL specifications.

• Problem framing using entities, locations, measures, rules and decision outputs
• Source assessment covering coverage, scale, currency and positional accuracy
• Query acceptance criteria defined with examples, tolerances and exception rules
• Data model sketches linking assets, events, zones and reference boundaries
• Performance targets for recurring reports, services and interactive maps
• Documentation structure for assumptions, methods, limitations and ownership

Participants can review spatial SQL for correctness, efficiency, maintainability and data-risk issues.

• Code review criteria covering predicates, SRIDs, units and index usage
• Diagnosing empty result sets from coordinate system mismatches
• Investigating duplicate records created through many-to-many spatial joins
• Comparing map outputs against SQL counts and sampled source records
• Refactoring repeated spatial expressions into views and database functions
• Peer review records capturing defects, decisions and approved corrections

Participants can build, review and present a complete documented spatial SQL analysis pack for an operational scenario.

• Define a spatial decision question, users, outputs and acceptance criteria
• Design tables, geometry columns, constraints and coordinate reference system choices
• Load and validate source datasets with documented quality findings
• Build spatial joins, proximity queries, aggregates and derived geometries
• Tune selected queries using indexes, statistics and execution-plan evidence
• Publish map-ready outputs through documented views and GeoJSON extracts
• Present methods, findings, limitations and recommended operational actions