| Safe Haskell | Safe-Inferred |
|---|---|
| Language | GHC2021 |
Database.Persist.Sql.Lifted.Expression.List
Synopsis
- in_ :: PersistField typ => SqlExpr (Value typ) -> SqlExpr (ValueList typ) -> SqlExpr (Value Bool)
- notIn :: PersistField typ => SqlExpr (Value typ) -> SqlExpr (ValueList typ) -> SqlExpr (Value Bool)
- subList_select :: PersistField a => SqlQuery (SqlExpr (Value a)) -> SqlExpr (ValueList a)
- valList :: PersistField typ => [typ] -> SqlExpr (ValueList typ)
- justList :: SqlExpr (ValueList typ) -> SqlExpr (ValueList (Maybe typ))
Documentation
in_ :: PersistField typ => SqlExpr (Value typ) -> SqlExpr (ValueList typ) -> SqlExpr (Value Bool) #
IN operator. For example if you want to select all Persons by a list
of IDs:
SELECT * FROM Person WHERE Person.id IN (?)
In esqueleto, we may write the same query above as:
select $from$ \person -> dowhere_$ person^.PersonId `in_`valListpersonIds return person
Where personIds is of type [Key Person].
notIn :: PersistField typ => SqlExpr (Value typ) -> SqlExpr (ValueList typ) -> SqlExpr (Value Bool) #
NOT IN operator.
subList_select :: PersistField a => SqlQuery (SqlExpr (Value a)) -> SqlExpr (ValueList a) #
Execute a subquery SELECT in an SqlExpression. Returns a
list of values.
valList :: PersistField typ => [typ] -> SqlExpr (ValueList typ) #
Lift a list of constant value from Haskell-land to the query.