persistent-sql-lifted-0.4.3.1: Monad classes for running queries with Persistent and Esqueleto
Safe HaskellSafe-Inferred
LanguageGHC2021

Database.Persist.Sql.Lifted.Expression.Number

Synopsis

Documentation

(+.) :: PersistField a => SqlExpr (Value a) -> SqlExpr (Value a) -> SqlExpr (Value a) infixl 6 #

This operator translates to the SQL operator +.

This does not require or assume anything about the SQL values. Interpreting what +. means for a given type is left to the database engine.

Example:

 user ^. UserAge +. val 10

(-.) :: PersistField a => SqlExpr (Value a) -> SqlExpr (Value a) -> SqlExpr (Value a) infixl 6 #

This operator translates to the SQL operator -.

This does not require or assume anything about the SQL values. Interpreting what -. means for a given type is left to the database engine.

Example:

 user ^. UserAge -. val 10

(/.) :: PersistField a => SqlExpr (Value a) -> SqlExpr (Value a) -> SqlExpr (Value a) infixl 7 #

This operator translates to the SQL operator /.

This does not require or assume anything about the SQL values. Interpreting what /. means for a given type is left to the database engine.

Example:

 user ^. UserAge /. val 10

(*.) :: PersistField a => SqlExpr (Value a) -> SqlExpr (Value a) -> SqlExpr (Value a) infixl 7 #

This operator translates to the SQL operator *.

This does not require or assume anything about the SQL values. Interpreting what *. means for a given type is left to the database engine.

Example:

 user ^. UserAge *. val 10

round_ :: (PersistField a, Num a, PersistField b, Num b) => SqlExpr (Value a) -> SqlExpr (Value b) #

ceiling_ :: (PersistField a, Num a, PersistField b, Num b) => SqlExpr (Value a) -> SqlExpr (Value b) #

floor_ :: (PersistField a, Num a, PersistField b, Num b) => SqlExpr (Value a) -> SqlExpr (Value b) #

min_ :: PersistField a => SqlExpr (Value a) -> SqlExpr (Value (Maybe (Nullable a))) #

max_ :: PersistField a => SqlExpr (Value a) -> SqlExpr (Value (Maybe (Nullable a))) #

sum_ :: (PersistField a, PersistField b) => SqlExpr (Value a) -> SqlExpr (Value (Maybe b)) #

avg_ :: (PersistField a, PersistField b) => SqlExpr (Value a) -> SqlExpr (Value (Maybe b)) #

castNum :: (Num a, Num b) => SqlExpr (Value a) -> SqlExpr (Value b) #

Allow a number of one type to be used as one of another type via an implicit cast. An explicit cast is not made, this function changes only the types on the Haskell side.

Caveat: Trying to use castNum from Double to Int will not result in an integer, the original fractional number will still be used! Use round_, ceiling_ or floor_ instead.

Safety: This operation is mostly safe due to the Num constraint between the types and the fact that RDBMSs usually allow numbers of different types to be used interchangeably. However, there may still be issues with the query not being accepted by the RDBMS or persistent not being able to parse it.

Since: esqueleto-2.2.9

castNumM :: (Num a, Num b) => SqlExpr (Value (Maybe a)) -> SqlExpr (Value (Maybe b)) #

Same as castNum, but for nullable values.

Since: esqueleto-2.2.9