The AND operator in PostgreSQL is a logical operator used to combine multiple conditions in a WHERE clause or other parts of a query. It’s used to ensure that all the specified conditions are true for a particular row to be included in the query result. The syntax for using the AND operator is as…
The LEAST function in postgreSQL is used to find the least (smallest) value among a list of expressions. It takes multiple arguments and returns the minimum value from those arguments. The syntax of the LEAST function is as follows: LEAST(expression1, expression2, …, expressionN) Here’s an example of how the LEAST function can be used: SELECT…
In PostgreSQL, the GREATEST function is used to find the greatest (largest) value among a list of expressions. It takes multiple arguments and returns the maximum value from those arguments. The syntax of the GREATEST function is as follows: GREATEST(expression1, expression2, …, expressionN) Here’s an example of how the GREATEST function can be used: SELECT…
The NULLIF function is used to compare two expressions and return NULL if they are equal, otherwise it returns the first expression. This function is often used to handle situations where you want to avoid having a particular value and replace it with NULL based on a condition. The syntax of the NULLIF function is…
The COALESCE function is used to return the first non-null expression from a list of expressions. It’s often used to provide a default value when dealing with nullable columns or expressions. If the first expression in the list is not NULL, the COALESCE function will return that expression; otherwise, it will return the first non-null…
The CASE statement in PostgreSQL is used to perform conditional logic within a query. It allows you to create conditional expressions that produce different results based on specified conditions. There are two forms of the CASE statement in PostgreSQL: the simple CASE and the searched CASE. SELECT column_name, CASE column_name WHEN value1 THEN result1 WHEN…
In PostgreSQL, the LOCALTIME function is used to retrieve the current local time without the date component. It returns the current time in the time data type, which includes the hours, minutes, seconds, and fractional seconds. The basic syntax of the LOCALTIME function is as follows: SELECT LOCALTIME; This query will return the current local…
In PostgreSQL, the EXTRACT function is used to extract specific components (such as year, month, day, hour, etc.) from date and time values. This function allows you to retrieve individual parts of a timestamp or interval. The basic syntax of the EXTRACT function is as follows: EXTRACT(field FROM source); where field is the part of…
In PostgreSQL, the CURRENT_TIMESTAMP function is used to retrieve the current date and time along with the time zone information. It returns the current timestamp in the timestamp with time zone data type, which includes the date, time, seconds, milliseconds, and the time zone offset. The basic syntax of the CURRENT_TIMESTAMP function is as follows:…
In PostgreSQL, the DATE_PART function is used to extract a specific element (e.g., year, month, day, hour, minute, second, etc.) from a date, time, or timestamp value. It returns the numeric value of the specified component. The basic syntax of the DATE_PART function is as shown below: DATE_PART(field, source); where field is the part of…