1. Sqlite

  • 1.17. SQLite AND/OR operator

    SQLite Of AND And OR Operator is used to compile multiple conditi...
    2025-10-25 12:31:16 UTC
  • 1.18. SQLite Update statement

    SQLite Of UPDATE The query is used to modify existing records in the table. You ...
    2025-10-25 12:31:12 UTC
  • 1.19. SQLite Delete statement

    SQLite Of DELETE The query is used to delete existing records in the table. You ...
    2025-10-25 12:31:14 UTC
  • 1.20. SQLite Like clause

    SQLite Of LIKE Operator is a text value that matches the pattern specified by a ...
    2025-10-25 12:31:16 UTC
  • 1.21. SQLite Glob clause

    SQLite’s GLOB Operator is a text value that matches the pattern specified by a wildcard. If the search ...
    2025-10-25 12:31:11 UTC
  • 1.22. SQLite Limit clause

    SQLite’s LIMIT Clause is used to restrict the value of the SELECT The amount ...
    2024-01-11 23:00:02 UTC
  • 1.23. SQLite Order By

    SQLite’s ORDER BY Clause is used to sort data in ascending or descending order based on one or more col...
    2025-10-25 12:31:15 UTC
  • 1.24. SQLite Group By

    SQLite’s GROUP BY Clause is used with SELECT Statement to group the same data...
    2025-10-25 12:31:13 UTC
  • 1.25. SQLite Having clause

    HAVING Clause allows you to specify conditions to filter the grouped results that will appear i...
    2025-10-25 12:31:14 UTC
  • 1.26. SQLite Distinct keyword

    SQLite’s DISTINCT Keywords vs. SELECT Statement to eliminate all duplicate re...
    2025-10-25 12:31:17 UTC
  • 1.27. SQLite PRAGMA

    SQLite’s PRAGMA The command is a special command that can be used to control various environment variab...
    2025-10-25 12:31:13 UTC
  • 1.28. SQLite constraint

    Constraints are rules that are enforced on the data columns of a table. These are used to limit the types of data that...
    2025-10-25 12:31:18 UTC
  • 1.29. SQLite Join

    SQLite’s Join Clause is used to combine records of tables in two or more databases. JOIN ...
    2025-10-25 12:31:11 UTC
  • 1.30. SQLite Unions clause

    SQLite’s UNION Clause / operator is used to merge two or more SELECT Statemen...
    2025-10-25 12:31:17 UTC
  • 1.31. SQLite NULL value

    SQLite’s NULL Is an item used to represent a missing value. One of the tables NULL ...
    2025-10-25 12:31:11 UTC
  • 1.32. SQLite alias

    You can temporarily rename the table or column to another name, which is called 别名 . The use of a table...
    2025-10-25 12:31:15 UTC
Principles, Technologies, and Methods of Geographic Information Systems  102

In recent years, Geographic Information Systems (GIS) have undergone rapid development in both theoretical and practical dimensions. GIS has been widely applied for modeling and decision-making support across various fields such as urban management, regional planning, and environmental remediation, establishing geographic information as a vital component of the information era. The introduction of the “Digital Earth” concept has further accelerated the advancement of GIS, which serves as its technical foundation. Concurrently, scholars have been dedicated to theoretical research in areas like spatial cognition, spatial data uncertainty, and the formalization of spatial relationships. This reflects the dual nature of GIS as both an applied technology and an academic discipline, with the two aspects forming a mutually reinforcing cycle of progress.