Question

我在oracle中遇到了以下语法来创建过程。我想知道语法中使用的是什么'，q'a，q'z和z'。

有人可以解释这些结构的用法。

**

viewControllers

**

注意：语法可能不完整。

Answer 1

此语法用于将引号之间的字符串处理为写入的位置;您决定要用作分隔符的字符，然后在字符串的开头和结尾使用它;一些例子：

select 'quote here: ''' , 'double quote'from dual union all
select q'@quote here: ''@', 'q syntax, double quote means two quotes' from dual union all
select q'@quote here: '@', 'q syntax, no need fou double quotes' from dual union all
select 'two quotes here: ''''', 'same thing to have two quotes' from dual union all
select q'@two quotes here: ''@', 'and two quotes with q syntax ' from dual union all
select q'@this is the delimiter char: @.@', 'the delimiter character can be used wherever in the string' from dual union all
select q'@@delimiter is in the beginning and in the end@@', 'you have to double the delimiter if you want it in the end or beginning' from dual

您可以查看文档here

Answer 2

Q＆＃39; ＆＃39;是一种使用嵌入式引号引用字符串文字的方法
e.g。

select q'x It's a string x' From dual;

It's a string
语法是q＆＃39; [...]＆＃39;，其中＆＃34; [＆＃34;和＆＃34;]＆＃34;是字符a＆＃39;和z＆＃39;在你的例子中。因此select q'z execute immediate q'a SELECT count(1) from dual a'z' from dual变为execute immediate q'a SELECT count(1) from dual a'

在示例查询下方

-- quoting string literals (new from 10G)

select q'aIt's string with embedded quotesa' from dual -- string terminated by chacter "a"
union all
select 'It''s string with embedded quotes' from dual--quotes using a 2 quotes
union all
select q'z execute immediate q'a SELECT count(1) from dual a'z' from dual ; -- your example

oracle中动态sql中的链接语句

2 个答案: