Tag: postgresql

PostgreSQL complex nested json data correction case

Directory Reference link Problem Description The first problem encountered: How to determine whether there are elements that meet the requirements in the nested json object array in the json field of each record The second problem encountered: the function is written while debugging, and it is necessary to output logs to observe the debugging results. […]

PostGreSQL: Data table inheritance

The brief history section of the PostGreSQL manual introduces: The object-relational database management system known as PostGreSQL was developed from the POSTGRES software package written by the University of California, Berkeley. After more than ten years of development, PostGreSQL is currently the most advanced open source database in the world. The object-relational database management system […]

Qlik Sense Enterprise Forgot PostgreSQL password

A password is provided during the installation of Qlik Sense Enterprise on Windows. If you forget your password, you can’t retrieve it; however, you can reset it by following the steps below. How to reset forgotten PostgreSQL password in Qlik… – Qlik Community – 1712725 If an incorrect password error is logged after the process […]

Connect to a PostgreSQL database using Python

This article describes the process of creating a connection to a database on PostgreSQL. We need prerequisites like installing PostgreSQL and creating a database as explained below. Install PostgreSQL on the system As the name suggests, PostgreSQL is a SQL system software created for efficient management of database systems. You need to create a database […]

postgresql practice

1. Environment setup Reference: http://www.lvesu.com/blog/main/cms-532.html 1.1. Install dependencies # Need to install postgresql-devel plug-in yum install postgresql-devel* # Install pg and py drivers: # Debian system: apt-get install libpq-dev python-dev # RedHat series: yum install libpqxx-devel python-devel # Installation is complete, then use pip install psycopg2 1.2. Install postgres (including psql) sudo apt-get -y install […]

1 Section 1 postgresql initialization creation

Table of Contents Table of Contents The first step is to create a user Step 2: Create space extension Step 3 Import the database result: Ending question: 1 database is occupied 2Commonly used statements 3 Change password 4External network access The first step is to create a user When creating a PG database, you need […]

PostgreSQL source code reading-WAL log reading read_local_xlog_page()

PostgreSQL source code reading-WAL log reading read_local_xlog_page() We explore the WAL log reading function read_local_xlog_page() function code. The code is selected from pg12, logicalfuns.c The read_page() function can obtain the contents of a specific data page The read_page() function is a function pointer in the XLogReaderState structure. The function pointer points to the logical_read_local_xlog_page() function […]

Idea connects postgresql database operations and establishes university and national map databases as well as function creation.

Posting background Because I learned the principles of spatial databases on the computer, I had the opportunity to create my own database and connect it to complete the questions. When I was working on the database principles before, I completed a preliminary understanding and use of Oracle, but the uninstallation of Oracle and the password […]

Keyword lookup in Postgresql

Query by keyword in Postgresql, generally using the like statement. for example: select name from poi where name like ‘%key word%’. But as we all know, this matching rate is not satisfactory. This article uses examples to use the pg_trgm extension to achieve a more perfect keyword query. Create a new data table as follows: […]