The json_build_object function is used to create a JSON object from key-value pairs. It allows you to construct a JSON object by specifying keys and their corresponding values. Each key-value pair you provide becomes a property in the resulting JSON object. Below is the basic syntax of using the json_build_object function: json_build_object(key1, value1, key2, value2,…
The json_build_array function in PostgreSQL is used to create a JSON array from a list of values. It takes any number of arguments and returns a JSON array containing those values. Each argument will be treated as an element of the resulting JSON array. Below is the basic syntax of using the json_build_array function: json_build_array(value1,…
The row_to_json function in PostgreSQL is used to convert a row of a table or a composite type (user-defined type) into its corresponding JSON representation. This function is particularly useful when you want to retrieve data from a table and represent it in JSON format. The basic syntax of the row_to_json function is as follows:…
The array_to_json function in PostgreSQL is a powerful tool that allows you to convert an array of values into its corresponding JSON representation. This function is part of PostgreSQL’s rich set of functions for working with JSON data, providing a seamless way to transform arrays into a format that’s compatible with JSON. Basic Syntax The…
The to_json function in PostgreSQL is used to convert a PostgreSQL row or value into its corresponding JSON representation. This function is often used when you want to convert data from a table or a single value into JSON format. Here are some common use cases for the to_json function: Convert a Row to JSON:…
You can insert multiple rows into a table using the INSERT INTO statement in PostgreSQL database. There are a few different ways to accomplish this, depending on your requirements and the format of the data you want to insert. The two common methods of inserting multiple values are: using the VALUES clause and using the…
A subquery (also known as a nested query or inner query) is a query that is embedded within another query. Subqueries are used to retrieve data that will be used in the main query’s conditions, expressions, or selection criteria. They are a powerful tool for combining multiple queries and performing more complex operations in a…
The EXCEPT keyword is used in a query to retrieve distinct rows from the result of the first query that are not present in the result of the second query. In other words, it returns the set difference between the results of two queries. The basic syntax of the EXCEPT operator is as follows: SELECT…
The CAST function is used to explicitly convert a value from one data type to another. It allows you to change the data type of a value, expression, or column to a different data type. This can be useful to perform operations that require compatible data types or when you need to ensure that the…
The PERCENT_RANK() function is used to calculate the relative rank of a row within a result set as a fraction between 0 and 1. It gives the percentage of rows that are ranked lower than the current row. This function is often used to determine the percentile of a particular value within a dataset. The…