1. Sqlite

  • 1.19. SQLite Delete statement

    SQLite Of DELETE The query is used to delete existing records in the table. You can use the WHERE Of the clause ...
    2025-10-25 13:32:45 UTC

  • 1.20. SQLite Like clause

    SQLite Of LIKE Operator is a text value that matches the pattern specified by a wildcard. If the search expression mat...
    2025-10-25 13:32:46 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 expression matches ...
    2025-10-25 13:32:42 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 columns. 1.23.1. ...
    2025-10-25 13:32:45 UTC

  • 1.24. SQLite Group By

    SQLite’s GROUP BY Clause is used with SELECT Statement to group the same data. In SELECT Statement, the GROUP ...
    2025-10-25 13:32:43 UTC

  • 1.25. SQLite Having clause

    HAVING Clause allows you to specify conditions to filter the grouped results that will appear in the final result. W...
    2025-10-25 13:32:45 UTC

  • 1.26. SQLite Distinct keyword

    SQLite’s DISTINCT Keywords vs. SELECT Statement to eliminate all duplicate records and get only one record. It is po...
    2025-10-25 13:32:47 UTC

  • 1.27. SQLite PRAGMA

    SQLite’s PRAGMA The command is a special command that can be used to control various environment variables and status flag...
    2025-10-25 13:32:44 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 can b...
    2025-10-25 13:32:48 UTC

  • 1.29. SQLite Join

    SQLite’s Join Clause is used to combine records of tables in two or more databases. JOIN is a means of combining field...
    2025-10-25 13:32:42 UTC

  • 1.30. SQLite Unions clause

    SQLite’s UNION Clause / operator is used to merge two or more SELECT Statement and does not return any duplicate rows....
    2025-10-25 13:32:47 UTC

  • 1.31. SQLite NULL value

    SQLite’s NULL Is an item used to represent a missing value. One of the tables NULL A value is a value that appears bla...
    2025-10-25 13:32:42 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 alias refers to th...
    2025-10-25 13:32:45 UTC

  • 1.33. SQLite trigger (Trigger)

    SQLite 触发器（Trigger） Is a callback function for the database that is automatically executed / called when a specified datab...
    2025-10-25 13:32:44 UTC

  • 1.34. SQLite transaction (Transaction)

    A Transaction is a unit of work that performs work on a database. A Transaction is a unit or sequence of work that is comple...
    2025-10-25 13:32:43 UTC

  • 1.35. SQLite Index (Index)

    Index is a special look-up table, which is used by database search engine to speed up data retrieval. Simply put, an index i...
    2025-10-25 13:32:41 UTC

Principles and Applications of WebGIS

 37

Web框架

 942

WEB基础

 287

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.