Copyright	(c) Eitan Chatav 2019
Maintainer	eitan@morphism.tech
Stability	experimental
Safe Haskell	Safe-Inferred
Language	Haskell2010

Squeal.PostgreSQL.Manipulation.Update

Contents

Update

Description

update statements

Synopsis

update :: (Has sch db schema, Has tab0 schema ('Table table), Updatable table updates, SListI row) => Aliased (QualifiedAlias sch) (tab ::: tab0) -> NP (Aliased (Optional (Expression 'Ungrouped '[] with db params ((tab ::: TableToRow table) ': from)))) updates -> UsingClause with db params from -> Condition 'Ungrouped '[] with db params ((tab ::: TableToRow table) ': from) -> ReturningClause with db params ((tab ::: TableToRow table) ': from) row -> Manipulation with db params row
update_ :: (Has sch db schema, Has tab0 schema ('Table table), KnownSymbol tab, Updatable table updates) => Aliased (QualifiedAlias sch) (tab ::: tab0) -> NP (Aliased (Optional (Expression 'Ungrouped '[] with db params '[tab ::: TableToRow table]))) updates -> Condition 'Ungrouped '[] with db params '[tab ::: TableToRow table] -> Manipulation with db params '[]

Update

update Source #

Arguments

:: (Has sch db schema, Has tab0 schema ('Table table), Updatable table updates, SListI row)
=> Aliased (QualifiedAlias sch) (tab ::: tab0)	table to update
-> NP (Aliased (Optional (Expression 'Ungrouped '[] with db params ((tab ::: TableToRow table) ': from)))) updates	update expressions, modified values to replace old values
-> UsingClause with db params from	FROM A table expression allowing columns from other tables to appear in the WHERE condition and update expressions.
-> Condition 'Ungrouped '[] with db params ((tab ::: TableToRow table) ': from)	WHERE condition under which to perform update on a row
-> ReturningClause with db params ((tab ::: TableToRow table) ': from) row	results to return
-> Manipulation with db params row

An update command changes the values of the specified columns in all rows that satisfy the condition.

>>> type Columns = '["col1" ::: 'Def :=> 'NotNull 'PGint4, "col2" ::: 'NoDef :=> 'NotNull 'PGint4]
>>> type Schema = '["tab1" ::: 'Table ('[] :=> Columns), "tab2" ::: 'Table ('[] :=> Columns)]
>>> :{
let
  manp :: Manipulation with (Public Schema) '[]
    '["col1" ::: 'NotNull 'PGint4,
      "col2" ::: 'NotNull 'PGint4]
  manp = update
    (#tab1 `as` #t1)
    (Set (2 + #t2 ! #col2) `as` #col1)
    (Using (table (#tab2 `as` #t2)))
    (#t1 ! #col1 ./= #t2 ! #col2)
    (Returning (#t1 & DotStar))
in printSQL manp
:}
UPDATE "tab1" AS "t1" SET "col1" = ((2 :: int4) + "t2"."col2") FROM "tab2" AS "t2" WHERE ("t1"."col1" <> "t2"."col2") RETURNING "t1".*

update_ Source #

Arguments

:: (Has sch db schema, Has tab0 schema ('Table table), KnownSymbol tab, Updatable table updates)
=> Aliased (QualifiedAlias sch) (tab ::: tab0)	table to update
-> NP (Aliased (Optional (Expression 'Ungrouped '[] with db params '[tab ::: TableToRow table]))) updates	modified values to replace old values
-> Condition 'Ungrouped '[] with db params '[tab ::: TableToRow table]	condition under which to perform update on a row
-> Manipulation with db params '[]

Update a row returning Nil.

>>> type Columns = '["col1" ::: 'Def :=> 'NotNull 'PGint4, "col2" ::: 'NoDef :=> 'NotNull 'PGint4]
>>> type Schema = '["tab" ::: 'Table ('[] :=> Columns)]
>>> :{
let
  manp :: Manipulation with (Public Schema) '[] '[]
  manp = update_ #tab (Set 2 `as` #col1) (#col1 ./= #col2)
in printSQL manp
:}
UPDATE "tab" AS "tab" SET "col1" = (2 :: int4) WHERE ("col1" <> "col2")