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acde210fdc
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/4460 GitOrigin-RevId: 7b772cd9fba6b612ad05eb1aca1fa13e6ae8556d
121 lines
4.2 KiB
Haskell
121 lines
4.2 KiB
Haskell
-- | Stuff gutted from Translate.Select.
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module Hasura.Backends.Postgres.Translate.Select.Internal.Helpers
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( mkFirstElementExp,
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mkLastElementExp,
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cursorIdentifier,
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startCursorIdentifier,
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endCursorIdentifier,
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hasNextPageIdentifier,
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hasPreviousPageIdentifier,
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pageInfoSelectAliasIdentifier,
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cursorsSelectAliasIdentifier,
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encodeBase64,
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fromTableRowArgs,
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selectFromToFromItem,
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functionToIdentifier,
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withJsonBuildObj,
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withForceAggregation,
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)
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where
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import Hasura.Backends.Postgres.SQL.DML qualified as S
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import Hasura.Backends.Postgres.SQL.Types (Identifier (..), QualifiedFunction, qualifiedObjectToText, toIdentifier)
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import Hasura.Backends.Postgres.Translate.Select.Internal.Aliases
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import Hasura.Backends.Postgres.Types.Function
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import Hasura.Prelude
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import Hasura.RQL.IR
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import Hasura.RQL.Types.Common (FieldName)
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import Hasura.RQL.Types.Function
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import Hasura.SQL.Backend
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-- | First element extractor expression from given record set
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-- For example:- To get first "id" column from given row set,
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-- the function generates the SQL expression AS `(array_agg("id"))[1]`
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mkFirstElementExp :: S.SQLExp -> S.SQLExp
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mkFirstElementExp expIdentifier =
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-- For Example
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S.SEArrayIndex (S.SEFnApp "array_agg" [expIdentifier] Nothing) (S.intToSQLExp 1)
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-- | Last element extractor expression from given record set.
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-- For example:- To get first "id" column from given row set,
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-- the function generates the SQL expression AS `(array_agg("id"))[array_length(array_agg("id"), 1)]`
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mkLastElementExp :: S.SQLExp -> S.SQLExp
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mkLastElementExp expIdentifier =
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let arrayExp = S.SEFnApp "array_agg" [expIdentifier] Nothing
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in S.SEArrayIndex arrayExp $
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S.SEFnApp "array_length" [arrayExp, S.intToSQLExp 1] Nothing
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cursorIdentifier :: Identifier
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cursorIdentifier = Identifier "__cursor"
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startCursorIdentifier :: Identifier
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startCursorIdentifier = Identifier "__start_cursor"
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endCursorIdentifier :: Identifier
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endCursorIdentifier = Identifier "__end_cursor"
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hasPreviousPageIdentifier :: Identifier
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hasPreviousPageIdentifier = Identifier "__has_previous_page"
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hasNextPageIdentifier :: Identifier
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hasNextPageIdentifier = Identifier "__has_next_page"
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pageInfoSelectAliasIdentifier :: Identifier
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pageInfoSelectAliasIdentifier = Identifier "__page_info"
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cursorsSelectAliasIdentifier :: Identifier
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cursorsSelectAliasIdentifier = Identifier "__cursors_select"
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encodeBase64 :: S.SQLExp -> S.SQLExp
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encodeBase64 =
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removeNewline . bytesToBase64Text . convertToBytes
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where
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convertToBytes e =
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S.SEFnApp "convert_to" [e, S.SELit "UTF8"] Nothing
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bytesToBase64Text e =
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S.SEFnApp "encode" [e, S.SELit "base64"] Nothing
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removeNewline e =
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S.SEFnApp "regexp_replace" [e, S.SELit "\\n", S.SELit "", S.SELit "g"] Nothing
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fromTableRowArgs ::
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Identifier -> FunctionArgsExpG (ArgumentExp S.SQLExp) -> S.FunctionArgs
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fromTableRowArgs prefix = toFunctionArgs . fmap toSQLExp
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where
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toFunctionArgs (FunctionArgsExp positional named) =
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S.FunctionArgs positional named
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toSQLExp =
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onArgumentExp
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(S.SERowIdentifier alias)
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(S.mkQIdenExp alias . Identifier)
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alias = mkBaseTableAlias prefix
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selectFromToFromItem :: Identifier -> SelectFrom ('Postgres pgKind) -> S.FromItem
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selectFromToFromItem pfx = \case
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FromTable tn -> S.FISimple tn Nothing
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FromIdentifier i -> S.FIIdentifier $ toIdentifier i
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FromFunction qf args defListM ->
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S.FIFunc $
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S.FunctionExp qf (fromTableRowArgs pfx args) $
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Just $ S.mkFunctionAlias (functionToIdentifier qf) defListM
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-- | Converts a function name to an 'Identifier'.
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--
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-- If the schema name is public, it will just use its name, otherwise it will
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-- prefix it by the schema name.
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functionToIdentifier :: QualifiedFunction -> Identifier
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functionToIdentifier = Identifier . qualifiedObjectToText
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-- uses json_build_object to build a json object
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withJsonBuildObj ::
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FieldName -> [S.SQLExp] -> (S.Alias, S.SQLExp)
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withJsonBuildObj parAls exps =
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(S.toAlias parAls, jsonRow)
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where
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jsonRow = S.applyJsonBuildObj exps
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-- | Forces aggregation
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withForceAggregation :: S.TypeAnn -> S.SQLExp -> S.SQLExp
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withForceAggregation tyAnn e =
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-- bool_or to force aggregation
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S.SEFnApp "coalesce" [e, S.SETyAnn (S.SEUnsafe "bool_or('true')") tyAnn] Nothing
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