oracle存储过程拼接动态sql

Question

v_sql := v_sql ||' and v_name ='''||v_name||'''';

后面为什么要加这么多引号呢？

Answer 1

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

Answer 2

现在知道了 那是为了让传入的字符串被两个单引号包裹住，但我用这种写法直接执行sql语句就会报错，只能用一个单引号包住的方式才能正确执行。为什么在存储过程里可以用两个单引号呢

Answer 3

为什么后面分别要加3个和4个引号