Android Room - Select query with LIKE

Question

I'm trying to make a query to search all objects whose names contain text:

@Query("SELECT * FROM hamster WHERE name LIKE %:arg0%")
fun loadHamsters(search: String?): Flowable<List<Hamster>>

Messages:

Error:no viable alternative at input 'SELECT * FROM hamster WHERE name LIKE %'
Error:There is a problem with the query: [SQLITE_ERROR] SQL error or missing database (near "%": syntax error)
Error:Unused parameter: arg0

Also, I'm trying:

@Query("SELECT * FROM hamster WHERE name LIKE '%:arg0%'")
fun loadHamsters(search: String?): Flowable<List<Hamster>>

Messages:

Error:Unused parameter: arg0

How to fix this?

Answer 1

You can just concat using SQLite string concatenation.

@Query("SELECT * FROM hamster WHERE name LIKE '%' || :search || '%'")
fun loadHamsters(search: String?): Flowable<List<Hamster>>

Answer 2

You should enclose the % characters in your input query - not in the query itself.

E.g. try this:

@Query("SELECT * FROM hamster WHERE name LIKE :arg0")
fun loadHamsters(search: String?): Flowable<List<Hamster>>

Then your String search value should look like:

search = "%fido%";
loadHamsters(search);

Furthermore, the binding parameter name should match the variable name, so rather than arg0 it should look like:

@Query("SELECT * FROM hamster WHERE name LIKE :search")
fun loadHamsters(search: String?): Flowable<List<Hamster>>