So I've been googling for a couple of hours and I still don't understand a single thing about escaping quotes in sql.
Can somebody please explain me if '''' in sql means ' why does select '('||''''||')' give (') why not (''')?
CodePudding user response：
A string in SQL must be enclosed in single quotes, e.g. 'a'
A single quote inside a SQL string is escaped by doubling it: '' - to create a string out of that, you need to enclose that in two single quotes: '''' - so the '' in the middle of that string are the same as the a in my first example.
The expression: '('||''''||')' consists of three string constants:
'('-->(''''-->'(as explained above)')'-->)