Oracle本身默认的是单引号，但是在大家写存储过程或者写SQL语句时，有时候需要拼SQL或者是SQL的值里需要传入含单引号的值，此时就需要使用两个单引号''''来进行转义，其实oracle本身提供了这种转换默认单引号为其他标识的方法那就是——"q"
q [Oracle's quote operator]
q'c text-to-be-quoted c'
c is a single character (called the quote delimiter).
With the «quote operator» apostrophes don't have to be doubled:
SQL> select q'#Oracle's quote operator#' from dual;
Q'#ORACLE'SQUOTEOPERATO
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Oracle's quote operator
begin
execute immediate q'#select * from abc#';
end;