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  1. (?&~>.) :: forall val nes nes1 . PersistEntity nes1 => EntityField val (Maybe nes1) -> NestedField nes1 nes -> NestedField val nes

    persistent-mongoDB Database.Persist.MongoDB

    Same as &~>., but works against a Maybe type

  2. (~>.) :: forall record typ emb . PersistEntity emb => EntityField record [emb] -> NestedField emb typ -> NestedField record typ

    persistent-mongoDB Database.Persist.MongoDB

    Point to an array field with an embedded object and give a deeper query into the embedded object. This level of nesting is not the final level. Use ->. or &->. to point to the final level.

  3. (!=.) :: forall v typ . PersistField typ => EntityField v typ -> typ -> Filter v

    persistent-mtl Database.Persist.Sql.Shim

    Non-equality check.

    Examples

    selectSimon :: MonadIO m => ReaderT SqlBackend m [Entity User]
selectSimon = selectList [UserName !=. "SPJ" ] []
    The above query when applied on dataset-1, will produce this: 
    +-----+-----+-----+
|id   |name |age  |
+-----+-----+-----+
|2    |Simon|41   |
+-----+-----+-----+

  4. (*=.) :: forall v typ . PersistField typ => EntityField v typ -> typ -> Update v

    persistent-mtl Database.Persist.Sql.Shim

    Assign a field by multiplication (*=).

    Examples

    multiplyAge :: MonadIO m => ReaderT SqlBackend m ()
multiplyAge = updateWhere [UserName ==. "SPJ" ] [UserAge *=. 2]
    The above query when applied on dataset-1, will produce this: 
    +-----+-----+--------+
|id   |name |age     |
+-----+-----+--------+
|1    |SPJ  |40 -> 80|
+-----+-----+--------+
|2    |Simon|41      |
+-----+-----+--------+

  5. (+=.) :: forall v typ . PersistField typ => EntityField v typ -> typ -> Update v

    persistent-mtl Database.Persist.Sql.Shim

    Assign a field by addition (+=).

    Examples

    addAge :: MonadIO m => ReaderT SqlBackend m ()
addAge = updateWhere [UserName ==. "SPJ" ] [UserAge +=. 1]
    The above query when applied on dataset-1, will produce this: 
    +-----+-----+---------+
|id   |name |age      |
+-----+-----+---------+
|1    |SPJ  |40 -> 41 |
+-----+-----+---------+
|2    |Simon|41       |
+-----+-----+---------+

  6. (-=.) :: forall v typ . PersistField typ => EntityField v typ -> typ -> Update v

    persistent-mtl Database.Persist.Sql.Shim

    Assign a field by subtraction (-=).

    Examples

    subtractAge :: MonadIO m => ReaderT SqlBackend m ()
subtractAge = updateWhere [UserName ==. "SPJ" ] [UserAge -=. 1]
    The above query when applied on dataset-1, will produce this: 
    +-----+-----+---------+
|id   |name |age      |
+-----+-----+---------+
|1    |SPJ  |40 -> 39 |
+-----+-----+---------+
|2    |Simon|41       |
+-----+-----+---------+

  7. (/<-.) :: forall v typ . PersistField typ => EntityField v typ -> [typ] -> Filter v

    persistent-mtl Database.Persist.Sql.Shim

    Check if value is not in given list.

    Examples

    selectSimon :: MonadIO m => ReaderT SqlBackend m [Entity User]
selectSimon = selectList [UserAge /<-. [40]] []
    The above query when applied on dataset-1, will produce this: 
    +-----+-----+-----+
|id   |name |age  |
+-----+-----+-----+
|2    |Simon|41   |
+-----+-----+-----+

  8. (/=.) :: forall v typ . PersistField typ => EntityField v typ -> typ -> Update v

    persistent-mtl Database.Persist.Sql.Shim

    Assign a field by division (/=).

    Examples

    divideAge :: MonadIO m => ReaderT SqlBackend m ()
divideAge = updateWhere [UserName ==. "SPJ" ] [UserAge /=. 2]
    The above query when applied on dataset-1, will produce this: 
    +-----+-----+---------+
|id   |name |age      |
+-----+-----+---------+
|1    |SPJ  |40 -> 20 |
+-----+-----+---------+
|2    |Simon|41       |
+-----+-----+---------+

  9. (<-.) :: forall v typ . PersistField typ => EntityField v typ -> [typ] -> Filter v

    persistent-mtl Database.Persist.Sql.Shim

    Check if value is in given list.

    Examples

    selectUsers :: MonadIO m => ReaderT SqlBackend m [Entity User]
selectUsers = selectList [UserAge <-. [40, 41]] []
    The above query when applied on dataset-1, will produce this: 
    +-----+-----+-----+
|id   |name |age  |
+-----+-----+-----+
|1    |SPJ  |40   |
+-----+-----+-----+
|2    |Simon|41   |
+-----+-----+-----+

    selectSPJ :: MonadIO m => ReaderT SqlBackend m [Entity User]
selectSPJ = selectList [UserAge <-. [40]] []
    The above query when applied on dataset-1, will produce this: 
    +-----+-----+-----+
|id   |name |age  |
+-----+-----+-----+
|1    |SPJ  |40   |
+-----+-----+-----+

  10. (<.) :: forall v typ . PersistField typ => EntityField v typ -> typ -> Filter v

    persistent-mtl Database.Persist.Sql.Shim

    Less-than check.

    Examples

    selectLessAge :: MonadIO m => ReaderT SqlBackend m [Entity User]
selectLessAge = selectList [UserAge <. 41 ] []
    The above query when applied on dataset-1, will produce this: 
    +-----+-----+-----+
|id   |name |age  |
+-----+-----+-----+
|1    |SPJ  |40   |
+-----+-----+-----+

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