Sql setting variables

Content provided by ChatGPT because I did not find this info online with my queries.

Microsoft SQL Server #

DECLARE @variable_name datatype;
SET @variable_name = value;

-- Example usage in a query
SELECT * FROM table WHERE column = @variable_name;

or shorter

DECLARE @variable_name datatype = value;

you can also leave out the datatype and it will be infered

DECLARE @variable_name = value;

MySQL / MariaDB #

-- Create and set a variable
SET @variable_name = value;

-- Example usage in a query
SELECT * FROM table WHERE column = @variable_name;

PostgreSQL #

-- Create and set a variable
DO $$
DECLARE
  variable_name datatype;
BEGIN
  variable_name := value;

  -- Example usage in a query
  SELECT * FROM table WHERE column = variable_name;
END $$;

Oracle #

-- Create and set a variable
variable variable_name datatype;
EXECUTE :variable_name := value;

-- Example usage in a query
SELECT * FROM table WHERE column = :variable_name;