PL/SQL:ORACLE中的感叹号

Question

以下查询中的感叹号(!)标记是什么？

l_sql := q'!
              SELECT CASE WHEN FILTER_CNT = 0 THEN NULL ELSE FILTER_LIST END AS FILTER_LIST
              FROM
              (
                  SELECT 'TABLE_NAME NOT LIKE ' || LISTAGG(''''||EXCLUSION_CRITERIA||'''', ' AND TABLE_NAME NOT LIKE ') WITHIN GROUP (ORDER BY ROWNUM) AS FILTER_LIST, COUNT(*) AS FILTER_CNT
                  FROM !'|| p_after_owner ||q'!.UT_TABLE_EXCLUSION
                  WHERE EXCLUSION_TYPE = 'P'
              )
            !';

Answer 1

q引用字符串的方法意味着您不必在字符串中转义单引号.

根据文档,它的工作原理如下:

q'<single character delimiter><text><single character delimiter>'

因此,!示例字符串中的s充当引号分隔符.

例如,如果要Don't worry, be happy在旧样式引用中使用字符串,那将成为:

'Don''t worry, be happy'

但新的引用机制将是:

q'!Don't worry, be happy!'

要么

q'{Don't worry, be happy}'

等等