[SPARK-43267][JDBC] Handle postgres unknown user-defined column as string in array

[Hisoka-X]

What changes were proposed in this pull request?

Spark SQL now doesn’t support creating data frame from a Postgres table that contains user-defined array column.

This PR support it as string.

Why are the changes needed?

Support handle user-defined array column in SPARK SQL with Postgres

Does this PR introduce any user-facing change?

No

How was this patch tested?

1. Add new test.
2. Tested in local.

CREATE DOMAIN not_null_text
    AS TEXT
    DEFAULT '';

create table films
(
    code         char(5 char)     not null
        constraint firstkey
            primary key,
    title        varchar(40 char) not null,
    did          bigint           not null,
    date_prod    date,
    kind         varchar(10 char),
    tz           timestamp with time zone,
    int_arr      integer[],
    column_name  not_null_text[],
    column_name2 not_null_text
);

INSERT INTO public.films (code, title, did, date_prod, kind, tz, int_arr, column_name, column_name2) VALUES (e'2
   ', 'fdas', 1, '2023-04-07 16:05:48', '2', null, null, null, null);
INSERT INTO public.films (code, title, did, date_prod, kind, tz, int_arr, column_name, column_name2) VALUES (e'4
   ', 'fdsa', 1, '2023-04-07 16:05:48', '4', null, null, null, null);
INSERT INTO public.films (code, title, did, date_prod, kind, tz, int_arr, column_name, column_name2) VALUES ('1    ', 'dafsdf', 1, '2023-04-04 14:43:51', '1', '2023-04-25 18:53:17.467000 +00:00', '{1,2,3}', '{1,fds,fdsa}', 'fdasfasdf');

Test Case

  test("jdbc array") {
    val connectionProperties = new Properties()
    connectionProperties.put("user", "system")
    connectionProperties.put("password", "system")
    spark.read.jdbc(
      url = "jdbc:postgresql://localhost:54321/test?useSSL=false&serverTimezone=UTC" +
        "&useUnicode=true&characterEncoding=utf-8",
      table = "TEST.public.films",
      connectionProperties
    ).show()
  }

Result

[Hisoka-X]

@cloud-fan @MaxGekk @hvanhovell Hi, PTAL. Thanks!

[cloud-fan]

@yaooqinn @ulysses-you

[yaooqinn]

thanks, merged to master