在Postgresql中，表示字符串时，用单引号将字符串包含起来。如 ‘foo’
如果字符串本身就包含单引号，就在有单引号的地方再加一个单引号。如要表示
O'Reilly
这个字符串。则表示成
'O''Reilly'
参考来源：
Postgresql 9.5官网文档
4.1. Lexical Structure
A string constant in sql is an arbitrary sequence of characters bounded by single quotes (‘),for example ‘This is a string’. To include a single-quote character within a string constant,write two adjacent single quotes,e.g.,‘Dianne”s horse’. Note that this is not the same as a double-quote character (“).
