Privileges control the actions that users and roles are allowed to perform on database objects such as tables, views, functions, and schemas. Privileges determine who can read, write, modify, or delete data within the database. PostgreSQL provides a fine-grained privilege system that allows you to control access at different levels of granularity. Here are some…
Roles are used to manage authentication and authorization. Roles can represent users or groups of users, and they control who can access the database and what actions they are allowed to perform. PostgreSQL provides two main types of roles: user roles and group roles (also known as role hierarchies). User Roles: User roles represent individual…
The NOT operator is used to negate a condition or expression. The NOT operator can be used with various other operators and functions to create negative conditions. The syntax for using the NOT operator is quite straightforward: NOT condition Here are a couple of examples to illustrate its usage: Using the NOT operator with a…
The less than or equal to operator is denoted by <=. This operator is used to compare two values and returns true if the left operand is less than or equal to the right operand; otherwise, it returns false. Here’s the general syntax of using the less than or equal to operator in PostgreSQL: value1…
The greater than or equal to operator is denoted by >=. This operator is used to compare two values and returns true if the left operand is greater than or equal to the right operand; otherwise, it returns false. Here’s the general syntax of using the greater than or equal to operator in PostgreSQL: value1…
In PostgreSQL, you have the ability to define your own custom data types, known as user-defined types (UDTs). This allows you to create data structures that suit your specific needs, encapsulate complex logic, and enhance data integrity. User-defined types can be composed of existing built-in data types or even other user-defined types. Here are some…
The hstore data type is used to store key-value pairs within a single column. It provides a way to store arbitrary metadata or attributes associated with a row in a structured form. The hstore data type is essentially a map or dictionary, where keys are strings and values can be of various data types. Here…
The array data type in postgreSQL is used to store ordered collections of elements of the same data type. Arrays provide a way to store multiple values in a single column, allowing you to work with lists of data in a structured manner. Here are some key points about the array data type: Here’s an…
The jsonb data type is an extension of the json data type that provides a more efficient and flexible way to store and query JSON (JavaScript Object Notation) data in postgreSQL database. jsonb stands for “JSON binary,” and it stores JSON data in a binary format that allows for improved storage and indexing. Here are…
The json data type is used to store JSON (JavaScript Object Notation) data. JSON is a widely used data interchange format that represents structured data in a human-readable text format. PostgreSQL introduced native support for the json data type to store and manipulate JSON documents directly within the database. Here are some key points about…