1. Sqlite

  • 1.33. SQLite trigger (Trigger)

    SQLite 触发器(Trigger) Is a callback function for the database that is automatically executed / called whe...
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  • 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 ...
    2025-10-25 12:31:12 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 i...
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  • 1.36. SQLite Indexed By

    The “INDEXED BY index-name” clause states that a named index is required to find the values in the previous table. ...
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  • 1.37. SQLite Alter command

    SQLite’s ALTER TABLE The command does not modify an existing table by performing a complete dump and re...
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  • 1.38. SQLite Truncate Table

    In SQLite, there is no TRUNCATE TABLE Command, but you can use the ...
    2025-10-25 12:31:12 UTC
  • 1.39. SQLite View (View)

    A View is nothing more than a SQLite statement stored in the database by the associated name. A View is actually a com...
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  • 1.40. SQLite subquery

    Subqueries, or internal queries, or nested queries, refer to the SQLite In the query ...
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  • 1.41. SQLite Autoincrement (auto increment)

    SQLite’s AUTOINCREMENT Is a keyword that automatically increments the value of a field in a table. We c...
    2025-10-25 12:31:12 UTC
  • 1.42. SQLite injection

    If your site allows users to enter through a web page and inserts input into a SQLite database, you face a security pr...
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  • 1.43. SQLite Explain (explanation)

    Before the SQLite statement, you can use the “EXPLAIN” keyword or the “EXPLAIN QUERY PLAN” phrase to describe the deta...
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  • 1.44. SQLite Vacuum

    VACUUM The command copies the contents of the master database to a tempdb file, then empties th...
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  • 1.45. SQLite date & time

    SQLite supports the following five date and time functions: ...
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  • 1.46. Common functions of SQLite

    SQLite has many built-in functions for dealing with string or numeric data. Here are some useful SQLite built-in funct...
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  • 1.47. SQLite-C *

    1.47.1. Installation ¶ We need to make sure that the SQLite library is ...
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  • 1.49. SQLite-PHP

    1.49.1. Installation ¶ Starting with PHP 5.3.0, the SQLite3 extension i...
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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.