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5. Postgresql

  • 5.1. PostgreSQL tutorial

    PostgreSQL is a free object-relational database server (ORDBMS) distributed under a flexible BSD license. PostgreSQL de…
    2025-10-25 13:32:25 UTC
  • 5.2. Install PostgreSQL on Linux

    Open the PostgreSQL website https://www.postgresql.org/ and click on the menu bar Download You can see that there are inst…
    2025-10-25 13:32:26 UTC
  • 5.3. Install PostgreSQL on Windows

    EnterpriseDB is used here to download and install, and EnterpriseDB is the only vendor in the world that offers enterprise-cla…
    2025-10-25 13:32:22 UTC
  • 5.4. Install PostgreSQL on Mac OS

    Using EnterpriseDB to download and install, EnterpriseDB is the only vendor in the world that offers PostgreSQL-based enterpri…
    2025-10-25 13:32:24 UTC
  • 5.5. PostgreSQL syntax

    By default, when PostgreSQL is installed, it comes with a command line tool SQL Shell(psql) . Linux The system can switc…
    2025-10-25 13:32:28 UTC
  • 5.6. PostgreSQL data type

    In this section, we will discuss the data types of PostgreSQL, which we set for each field when we created the table. Benefi…
    2025-10-25 13:32:22 UTC
  • 5.7. PostgreSQL creates a database

    PostgreSQL can create a database in the following three ways: 1、使用 CREATE DATABASE SQL 语句来创建。 2、使用 createdb 命令来创建。 …
    2025-10-25 13:32:26 UTC
  • 5.8. PostgreSQL Select Database

    In the previous section, we talked about how to create a database, and then we discussed how to select the database we created…
    2025-10-25 13:32:27 UTC
  • 5.9. PostgreSQL deletes the database

    PostgreSQL can delete a database in the following three ways: 1、使用 DROP DATABASE SQL 语句来删除。 2、使用 dropdb 命令来删除。 3、使…
    2025-10-25 13:32:27 UTC
  • 5.11. PostgreSQL delete table

    PostgreSQL uses DROP TABLE statements to delete tables, including table data, rules, triggers, and so on, so be careful to del…
    2025-10-25 13:32:25 UTC
  • 5.12. PostgreSQL mode (SCHEMA)

    The PostgreSQL schema (SCHEMA) can look like a collection of tables. A schema can contain views, indexes, data types, functi…
    2025-10-25 13:32:22 UTC
  • 5.13. PostgreSQL INSERT INTO statement

    The PostgreSQL INSERT INTO statement is used to insert new records into the table. We can insert one row or multiple rows at…
    2025-10-25 13:32:27 UTC
  • 5.14. PostgreSQL SELECT statement

    The PostgreSQL SELECT statement is used to select data from the database. The results are stored in a result table called th…
    2025-10-25 13:32:24 UTC
  • 5.15. PostgreSQL operator

    An operator is a symbol that tells the compiler to perform a specific mathematical or logical operation. The PostgreSQL oper…
    2025-10-25 13:32:24 UTC
  • 5.17. PostgreSQL WHERE clause

    In PostgreSQL, when we need to query data from a single table or multiple tables according to specified conditions, we can add…
    2025-10-25 13:32:23 UTC
  • 5.18. PostgreSQL AND & OR operator

    In PostgreSQL, AND and OR, also known as join operators, are used to narrow the scope of a query when querying data, and we ca…
    2025-10-25 13:32:23 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.