Double quotation marks and identifiers
When we create a table or query, even if we use lowercase, the results are still larger. If you want to see or store lowercase identifiers in data dictionaries, you have to use double quotes, so identifiers are case-sensitive, or include spaces in identifiers, or use reserved words as identifiers. You have to use a quote identifier enclosed in double quotation marks.
By the way, there are other things about single and double quotes. The following is the result of the original query statement for comparison.
Four single quotation marks can output a single quote, and the resulting result is in single quotation marks:
Two single quotation marks include a double quotation mark and output a double quotation mark, resulting in double quotation marks:
