PostgreSQL data types, sql queries, functions, views
In order to connect to a PostgreSQL database, you must have a PostgreSQL user. A user in PostgreSQL has a username and a password to connect to the PostgreSQL server. Additionally, you can grant him various permissions to carry out his work. It is also possible to form a user …
PostgreSQL provides the psql utility to connect to and communicate with PostgreSQL databases. psql provides a command-line interface for connecting to a PostgreSQL instance. Every installation of the PostgreSQL server comes with psql, which is the default client for interacting with the server. To work with PostgreSQL databases, psql offers …
PostgreSQL provides various date and time functions. One of the common functions is CURRENT_TIMESTAMP. PostgreSQL provides the CURRENT_TIMSTAMP function to show the current timestamp. The timestamp includes both the date and time information, along with time zone information. We can use the CURRENT_TIMSTAMP function in select queries and insert or …
PostgreSQL is an open-source relational database system. One of the common tasks of a PostgreSQL developer is to show all tables from a database. PostgreSQL provides two ways to list all tables from a database. PSQL Command Line Method PSQL allows us to interact through a terminal-based front-end. To list …
A column can be removed from PostgreSQL once it has been created. The ALTER TABLE command can be used to delete a column. You must specify both the name of the table and the desired column alongside the alter table command to delete a column in PostgreSQL. Syntax The syntax …
PostgreSQL offers a range of data types. Use ALTER TABLE command to alter column type to a different data type. The ALTER TABLE command syntax. Alter Column Type Example (Change Type Integer to VARCHAR) For example, we have the “item_type” column, which is of the integer data type. In this …
The data types define the types of data that can be kept in a table column. PostgreSQL provides various data types for different needs. In this post, you will learn about various data types and sizes in PostgreSQL. In addition, you can create your own type in PostgreSQL. Data Types …
A table is made up of rows and columns. After a table is created in a database, the first action a SQL developer takes is to insert data into it to create a new row. One row of data is inserted at a time. To insert data into the PostgreSQL …
One unique feature of PostgreSQL is the ability to insert multiple rows at once with a single command. To insert multiple rows, you need to specify column names and provide a list of rows with comma-separated values in the INSERT INTO command. If a table has an auto-increment field, you …
Epoch time is an industry standard and is used in various API’s and applications. The epoch time is the number of seconds that have passed since January 1, 1970, at 00:00:00 UTC. Epoch time is consistent across various computer systems and is not affected by time zone differences. It only …