如何从 postgres 文本列 json 字符串数组中删除值？

Question

I have a postgresql table with a column that is a text datatype. This column value is a JSON string array. These values could be in any order such as

["a", "b", "c"] 

or

["c", "a", "b", "d"] 

or

["a"]

Now one of these values "b" is no longer used and needs to be removed from each record in the table.

so ["a", "b", "c"] should be converted to ["a", "c"]

I have looked into using one of the postgres functions array_remove() but haven't been able to get it to work.

Is it possible to convert to an array type and convert back to a string after using remove?

Answer 1

Use a jsonb value (cast your text if necessary) and the - operator:

UPDATE table SET col = col::jsonb - 'a';

^{( online demo )}