Adaptation to Mysql

[jonschoning]

Adaptation to Mysql

[jonschoning]

I haven't tested if this works at all, but my first guess would be something like this

import Database.Esqueleto.Internal.Internal (unsafeSqlFunction, SqlExpr(..), noMeta, valueToFunctionArg)

mysqlGroupConcat ::
     PersistField a
  => SqlExpr (Value a)
  -> SqlExpr (Value a)
  -> SqlExpr (Value Text)
mysqlGroupConcat expr sep =
  ERaw noMeta $ \_ info ->
    let (tlbExpr, _) = valueToFunctionArg info expr
        (tlbSep, valSep) = valueToFunctionArg info sep
    in ("GROUP_CONCAT(" <> tlbExpr <> " SEPARATOR '" <> tlbSep <> "')", valSep)

[amxyz-cyber]

Hi,
many thanks for your help. I had to change the code a bit. It compiled successfully. But when starting the web server, mysql issued an error message because of a wrong syntax. This is the code that worked for me:

mysqlGroupConcat ::
       PersistField a
  => SqlExpr (Value a)
  -> SqlExpr (Value Text)
mysqlGroupConcat expr =
  ERaw noMeta $ \_ info ->
    let (tlbExpr, yx) = valueToFunctionArg info expr
    in ("GROUP_CONCAT(" <> tlbExpr <> " SEPARATOR ' ' )", yx)

I also found out why your query doesn't yield any results. It's because of the like-operator. But when performing a simple query of your database using the Mysql workbench it works. So I had to use the match against function for fulltext search in mysql. As for the match against function your code was really helpful. And now it's working.

[jonschoning]

Excellent - glad you got it working