Add the following code to main.py to get a note given its id. Introduction the dollar-quoted string constant syntax. In PostgreSQL, you use single quotes for a string constant like this: select 'String constant'; Code language: PostgreSQL SQL dialect and PL/pgSQL (pgsql) When a string constant contains a single quote ( ' ), you need to escape .... Contrary to C where NULL is 0, in Java NULL means the variable references do have value. The value can be tested against NULL by equality operators. When we print the null value, it will print the null. In Java, null is case sensitive and it must be in all small letters as “null”. Shell. You can also use char (39) as a single quote. Example. Select char (39) + name + char (39) from sysobjects. Just build your string using char (39) to surround your strings. I find it alot easier.