Mapping of PostgreSQL's type 'real' does not work

[64pcyk]

Hello, Kei-san! I am trying to use Haskell-Relational-Record with PostgreSQL 12 (psql (12.1 (Debian 12.1-1.pgdg100+1))) and when I defined a table containing simple types (text, integer) - with defineTableFromDB - it's OK. But when I try to do the same for table with SQL type real then I get an error:

/root/xyz/pgsql-poc/hrr/src/Countrylanguage.hs:22:3: error:
    • No instance for (PersistableWidth Float)
        arising from a use of ‘Database.Record.Persistable.genericFieldOffsets’
    • In the first argument of ‘Database.Record.Persistable.getProductConst’, namely
        ‘(Database.Record.Persistable.genericFieldOffsets ::
            Database.Record.Persistable.ProductConst (GHC.Arr.Array Int Int) Countrylanguage)’
      In the expression:
        Database.Record.Persistable.getProductConst
          (Database.Record.Persistable.genericFieldOffsets ::
             Database.Record.Persistable.ProductConst (GHC.Arr.Array Int Int) Countrylanguage)
      In an equation for ‘columnOffsetsCountrylanguage’:
          columnOffsetsCountrylanguage
            = Database.Record.Persistable.getProductConst
                (Database.Record.Persistable.genericFieldOffsets ::
                   Database.Record.Persistable.ProductConst (GHC.Arr.Array Int Int) Countrylanguage)
   |
22 | $(defineTable2
   |   ^^^^^^^^^^^^...

/root/xyz/pgsql-poc/hrr/src/Countrylanguage.hs:22:3: error:
    • No instance for (ToSql Database.HDBC.SqlValue.SqlValue Float)
        arising from a use of ‘Database.Record.ToSql.$dmrecordToSql’
    • In the expression:
        Database.Record.ToSql.$dmrecordToSql
          @(Database.HDBC.SqlValue.SqlValue) @(Countrylanguage)
      In an equation for ‘recordToSql’:
          recordToSql
            = Database.Record.ToSql.$dmrecordToSql
                @(Database.HDBC.SqlValue.SqlValue) @(Countrylanguage)
      In the instance declaration for
        ‘ToSql Database.HDBC.SqlValue.SqlValue Countrylanguage’
   |
22 | $(defineTable2
   |   ^^^^^^^^^^^^...

/root/xyz/pgsql-poc/hrr/src/Countrylanguage.hs:22:3: error:
    • No instance for (FromSql Database.HDBC.SqlValue.SqlValue Float)
        arising from a use of ‘Database.Record.FromSql.$dmrecordFromSql’
    • In the expression:
        Database.Record.FromSql.$dmrecordFromSql
          @(Database.HDBC.SqlValue.SqlValue) @(Countrylanguage)
      In an equation for ‘recordFromSql’:
          recordFromSql
            = Database.Record.FromSql.$dmrecordFromSql
                @(Database.HDBC.SqlValue.SqlValue) @(Countrylanguage)
      In the instance declaration for
        ‘FromSql Database.HDBC.SqlValue.SqlValue Countrylanguage’
   |
22 | $(defineTable2
   |   ^^^^^^^^^^^^...

/root/xyz/pgsql-poc/hrr/src/Countrylanguage.hs:22:3: error:
    • No instance for (PersistableWidth Float)
        arising from a use of ‘Database.Relational.Pi.Unsafe.definePi’
    • In the expression:
        (Database.Relational.Pi.Unsafe.definePi
           $ (columnOffsetsCountrylanguage GHC.Arr.! 3))
      In an equation for ‘Database.Relational.OverloadedProjection.projection’:
          Database.Relational.OverloadedProjection.projection _
            = (Database.Relational.Pi.Unsafe.definePi
                 $ (columnOffsetsCountrylanguage GHC.Arr.! 3))
      In the instance declaration for
        ‘Database.Relational.OverloadedProjection.HasProjection
           "percentage" Countrylanguage Float’
   |
22 | $(defineTable2
   |   ^^^^^^^^^^^^...

This is the code which describes the table:

...
defineTable2 :: String -> String -> [Name] -> Q [Dec]
defineTable2 = defineTableFromDB connectDatabase driverPostgreSQL
...

-- in another module:
...
$(defineTable2
    "public" "countrylanguage"
    [''Show, ''Generic])
...

The table "countrylanguage" is a table from the famous database "world" for PostgreSQL, which looks like:

postgres=# \dt
              List of relations
 Schema |      Name       | Type  |  Owner   
--------+-----------------+-------+----------
 public | city            | table | postgres
 public | country         | table | postgres
 public | countrylanguage | table | postgres

and a specially the table "countrylanguage" looks like:

postgres=# \d countrylanguage
               Table "public.countrylanguage"
   Column    |     Type     | Collation | Nullable | Default 
-------------+--------------+-----------+----------+---------
 countrycode | character(3) |           | not null | 
 language    | text         |           | not null | 
 isofficial  | boolean      |           | not null | 
 percentage  | real         |           | not null | 
Indexes:
    "countrylanguage_pkey" PRIMARY KEY, btree (countrycode, language)
Foreign-key constraints:
    "countrylanguage_countrycode_fkey" FOREIGN KEY (countrycode) REFERENCES country(code)

Is it an error? Or I miss something? How to fix it? I found some examples with the type "Float" for SQLite3, but why it does not work for PostgreSQL, I have not idea.

PS. Very similar code works fine for table "city" which does not contain columns of "real" type.

[64pcyk]

I'll add only that I tried also:

...
defineTable1 :: [(String, TypeQ)] -> String -> String -> [Name] -> Q [Dec]
defineTable1 tmap = defineTableFromDB connectDatabase (driverPostgreSQL { typeMap = tmap })
...

-- in another module
...
$(defineTable1
    [
        ("real", [t|Double|]),
        ("float", [t|Double|]),
        ("double", [t|Double|])
    ]
    "public" "countrylanguage"
    [''Show, ''Generic])
...

but errors are the same (about missing instances for type Float).