JIYIK CN >

数据库连接 A string is an expression in which there are all the parameters necessary to establish a connection from a terminal device to a database. It contains databases 用户名 , 密码 , 名称 , 主机地址 and 端口 . This con...

This article will discuss the timestamp types in PostgreSQL and show how they differ. Timestamps in PostgreSQL In PostgreSQL, there are two types of timestamps. Timestamp without time zone Timestamp with time zone The first stores the local...

if Statement evaluates a condition by returning true or false value. We can use it to perform condition based queries. This article will teach you how to write if conditional statements and understand how conditional statements can help you...

This article guides you through using the UPDATE and JOIN statements to update a table. Generate a shipment example in PostgreSQL Consider a store that sells food. Every time a shipment arrives, the price of the product is updated to reflec...

This article will discuss different types of ranges to compare dates in PostgreSQL. Date ranges in PostgreSQL By default, PostgreSQL provides some ranges to compare values. In particular, we can use daterange and between to compare dates. T...

This article shows how to check the version of Postgres. Checking Postgres Version in Windows C: \ Users \ Admin psql -- version psql ( PostgreSQL ) 14.0 C : \ Users \ Admin postgres -- version postgres ( PostgreSQL ) 14.0 The version shown...

A CSV file is .csv a text file with a .CSV extension and the contents are separated by commas. This file can achieve different goals, such as loading data into database tables and importing data into Google and Excel spreadsheets. When work...

PostgreSQL is an object-relational database system, which means it can support more complex data types than its competitor MySQL. Apart from the above differences, when writing queries for PostgreSQL and MySQL or other database systems, the...

Data backup is a critical process to ensure that preventive measures are effective in the event of an incident such as data loss. We can back up data in different forms and ways depending on the size and environment. This article will discu...

This article discusses how to import SQL files in PostgreSQL. psql Import SQL files in PostgreSQL using command To import the SQL file, run the following command: psql - U dbuser - h localhost databasename filename. sql If the file is locat...

This article shows how to change a column type to another data type in Postgres. ALTER TABLE To change the column type in Postgres, use the command ALTER TABLE table_name ALTER COLUMN column_name [ SET DATA ] TYPE new_type ; Use 表名 , , 列...

In this article, we will change the user password in Postgres. Changing User Passwords in Postgres Using Windows Open from the menu or search bar SQL Shell (psql) . Connect to the default database using the default port. If you set it up wi...

Today we will learn how to add constraints after the rows in a table have been created UNIQUE . The UNIQUE constraint guarantees that the data in a row is unique in that column. So if the column ID exists, all rows will have unique values,...

Today, we will learn how to find a value in a PostgreSQL string and select it if it matches certain conditions. Suppose you have a string carabc and want to see if it contains a value car . Therefore, you will try to use a function that tel...

Today, we will learn how to kill or stop a running query in the background when working with PostgreSQL database. This may happen if the frontend stops working but a background process is still running. In this case, you may want to kill th...