1. Sqlite

  • 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. If the ...
    2025-10-25 13:32:45 UTC
  • 1.37. SQLite Alter command

    SQLite’s ALTER TABLE The command does not modify an existing table by performing a complete dump and reloading of the data...
    2025-10-25 13:32:45 UTC
  • 1.38. SQLite Truncate Table

    In SQLite, there is no TRUNCATE TABLE Command, but you can use the SQLite Of DELETE Command to delete all data f...
    2025-10-25 13:32:43 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 combinati...
    2025-10-25 13:32:41 UTC
  • 1.40. SQLite subquery

    Subqueries, or internal queries, or nested queries, refer to the SQLite In the query WHERE The query statement is em...
    2025-10-25 13:32:46 UTC
  • 1.41. SQLite Autoincrement (auto increment)

    SQLite’s AUTOINCREMENT Is a keyword that automatically increments the value of a field in a table. We can use the on a spe...
    2025-10-25 13:32:43 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 problem ...
    2025-10-25 13:32:42 UTC
  • 1.43. SQLite Explain (explanation)

    Before the SQLite statement, you can use the “EXPLAIN” keyword or the “EXPLAIN QUERY PLAN” phrase to describe the details of...
    2025-10-25 13:32:44 UTC
  • 1.44. SQLite Vacuum

    VACUUM The command copies the contents of the master database to a tempdb file, then empties the master database, and re...
    2025-10-25 13:32:43 UTC
  • 1.45. SQLite date & time

    SQLite supports the following five date and time functions: Serial number Function Example 1 ...
    2025-10-25 13:32:44 UTC
  • 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 functions, ...
    2025-10-25 13:32:41 UTC
  • 1.47. SQLite-C *

    1.47.1. Installation ¶ We need to make sure that the SQLite library is already available on the machine before we use...
    2025-10-25 13:32:42 UTC
  • 1.49. SQLite-PHP

    1.49.1. Installation ¶ Starting with PHP 5.3.0, the SQLite3 extension is enabled by default. Can be used at compile t...
    2025-10-25 13:32:43 UTC
  • 1.50. SQLite-Perl

    1.50.1. Installation ¶ SQLite3 can be used Perl DBI The module is integrated with Perl. The Perl DBI modu...
    2025-10-25 13:32:47 UTC
  • 1.51. SQLite-Python

    1.51.1. Installation ¶ SQLite3 can integrate with Python using the sqlite3 module. The sqlite3 module is written by G...
    2025-10-25 13:32:48 UTC
《地理信息系统原理、技术与方法》  97

最近几年来,地理信息系统无论是在理论上还是应用上都处在一个飞速发展的阶段。 GIS被应用于多个领域的建模和决策支持,如城市管理、区划、环境整治等等,地理信息成为信息时代重要的组成部分之一; “数字地球”概念的提出,更进一步推动了作为其技术支撑的GIS的发展。 与此同时,一些学者致力于相关的理论研究,如空间感知、空间数据误差、空间关系的形式化等等。 这恰好说明了地理信息系统作为应用技术和学科的两个方面,并且这两个方面构成了相互促进的发展过程。