Question

Whenever we are creating a table, just we are specify as, CREATE TABLE table_name in any of the database system. When we are creating a table in postgre then we use,
CREATE TABLE "tabl_name". Is there any difference when we are using the double quotes " " for creation of table in postgreSql.

Answer 1

Actually there are a few differences.

Double quotes tells the parser that what is contained is a case-sensitive identifier, to be read literally.

This leads to a number of differences. You can do things like:

CREATE TABLE "table" ( ... );

but not

CREATE TABLE table (...);

Not only is it case sensitive (PostgreSQL folds unquoted identifiers to lower case) but it can include otherwise forbidden keywords.

This means however that afterwards you must use things like:

SELECT * FROM "table"

But you can’t

SELECT * FROM table