How to use 'LIKE' function to select array of Strings with JOOQ

问题

I now want to use 'like' function with JOOQ to select data including array of string data by not case sensitive and partitial-match.

Table schema is:

CREATE TABLE favorites (
    id int,
    items    varchar(100)[]
);

Sample data is:

INSERT INTO favorites (id, items)
    VALUES (1, '{orange, lemon, banana}');
INSERT INTO favorites (id, items)
    VALUES (2, '{apple, grape}');

To get first data, SQL is like:

SELECT id, items FROM favorites WHERE 'orange' = ANY (items);

My Goal is to select data by case-sensitive and partitial-match like: For example, using likeIgnoreCase("OraNge") or like("%ang%") ?

To develop below code with LIKE function:

Connection connection = ...;
DSLContext context = DSL.using(connection, ...);
List<Table> table = context.select().from(TABLE).fetchInto(Table.class);

How can I use like function?

Thank you in Advance.

回答1:

The PostgreSQL value = ANY (array) operator cannot match values like the LIKE predicate. You will need to resort to an actual LIKE predicate instead. In SQL, you'd write:

SELECT id, items
FROM favorites
WHERE EXISTS (SELECT * FROM unnest(items) AS t(item) WHERE item ILIKE '%OraNge%')

Or, with jOOQ:

context.select(FAVORITES.ID, FAVORITES.ITEMS)
       .from(FAVORITES)
       .whereExists(
            selectFrom(unnest(FAVORITES.ITEMS).as("t", "item")
           .where(field(name("item", String.class)).likeIgnoreCase("%OraNge"))
       )
       .fetch();

The jOOQ version, as always, assumes you have this static import:

import static org.jooq.impl.DSL.*;

回答2:

In addition, here are a few ways to use LIKE. You can always use the jOOQ LIKE predicates, see their documentation. In my second example, I use sql syntax in a string, just to prove you can. You can also use contains/startsWith/endsWith like you would with strings.

jooq.dsl()
  .select()
  .from(MY_TABLE)
  .where(Employee.EMPLOYEES.LAST_NAME.like("ER")));

jooq.dsl()
  .select()
  .from(EMPLOYEES)
  .where(Employee.EMPLOYEES.LAST_NAME.like("ER"))
  .and("first_name like ?", "ST"));

来源：https://stackoverflow.com/questions/41557902/how-to-use-like-function-to-select-array-of-strings-with-jooq

标签

java

sql

postgresql

jooq