PostgreSQL How to query String array

Question

I am trying to write a query to check if an element is within an array of Strings.

Here is my simple select query along with the output

select languages from person limit 3;
{CSS,HTML,Java,JavaScript,Python}
{JavaScript,Python,TensorFlow}
{C++,Python}

How do I write a query to find all people who have "Java" as a listed language they know?
I tried following the syntax but it isn't working.

select languages from person where languages @> ARRAY['Java']::varchar[];

Answer 1

尝试这个

select languages from person where 'Java' = ANY (string_to_array(languages , ','))

Answer 2

You need to use a string constant on the left side, and the ANY operator on the array column:

select languages 
from person 
where 'Java' = any(languages);

This assumes languages is defined as text[] or varchar[] as your sample output indicates

Answer 3

您可以搜索多个模式，用 POSIX 正则表达式前面的正则表达式匹配运算符 '~' 替换 '=' 运算符，例如：

select languages from person where '[Java,Php]' ~ ANY (string_to_array(languages , ','))