可以使用如下的方式:
STR := q'[ CREATE TABLE TNAME AS SELECT ... FROM INPUT_TABLE IP WHERE ((IP.DATE_FIELD = TO_DATE('12.08.2013', 'DD.MM.sYYYY'))) ]';
解决方案来自:https://stackoverflow.com/questions/18096740/use-of-single-quote-and-double-single-quote-in-pl-sql-block
以上