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0060a48009
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/4338 GitOrigin-RevId: c2125275b32a5084c5a96afba79d4cb6c65687a8
77 lines
3.1 KiB
Haskell
77 lines
3.1 KiB
Haskell
-- | This module defines the top-level translation functions pertaining to
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-- queries that are not aggregation queries, i.e. so-called "simple" selects
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-- into Postgres AST.
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module Hasura.Backends.Postgres.Translate.Select.Simple
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( mkSQLSelect,
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selectQuerySQL,
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)
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where
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import Control.Monad.Writer.Strict (runWriter)
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import Database.PG.Query (Query, fromBuilder)
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import Hasura.Backends.Postgres.SQL.DML qualified as S
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import Hasura.Backends.Postgres.SQL.IdentifierUniqueness (prefixNumToAliases)
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import Hasura.Backends.Postgres.SQL.Types (IsIdentifier (toIdentifier))
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import Hasura.Backends.Postgres.Translate.Select.AnnotatedFieldJSON
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import Hasura.Backends.Postgres.Translate.Select.Internal.Extractor (asJsonAggExtr)
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import Hasura.Backends.Postgres.Translate.Select.Internal.GenerateSelect (generateSQLSelectFromArrayNode)
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import Hasura.Backends.Postgres.Translate.Select.Internal.Process (processAnnSimpleSelect)
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import Hasura.Backends.Postgres.Translate.Types
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import Hasura.Prelude
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import Hasura.RQL.IR.Select
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( AnnSelectG (_asnStrfyNum),
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AnnSimpleSelect,
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)
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import Hasura.RQL.Types.Backend (Backend)
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import Hasura.RQL.Types.Common
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( FieldName (FieldName),
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JsonAggSelect,
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)
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import Hasura.SQL.Backend (BackendType (Postgres))
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import Hasura.SQL.Types (ToSQL (toSQL))
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-- | Translates IR to Postgres queries for simple SELECTs (select queries that
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-- are not aggregations, including subscriptions).
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--
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-- See 'mkSQLSelect' for the Postgres AST.
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selectQuerySQL ::
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forall pgKind.
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(Backend ('Postgres pgKind), PostgresAnnotatedFieldJSON pgKind) =>
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JsonAggSelect ->
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AnnSimpleSelect ('Postgres pgKind) ->
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Query
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selectQuerySQL jsonAggSelect sel =
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fromBuilder $ toSQL $ mkSQLSelect jsonAggSelect sel
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mkSQLSelect ::
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forall pgKind.
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( Backend ('Postgres pgKind),
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PostgresAnnotatedFieldJSON pgKind
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) =>
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JsonAggSelect ->
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AnnSimpleSelect ('Postgres pgKind) ->
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S.Select
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mkSQLSelect jsonAggSelect annSel =
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let permLimitSubQuery = PLSQNotRequired
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-- run an intermediary step in order to obtain:
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-- SelectSource: the primary source, along with its where clause and sorting/slicing information
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-- NodeExtractors: a map from aliases which need to be selected to the corresponding required SQLExp to select the value
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-- JoinTree: the join tree required for relationships (built via @MonadWriter@)
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((selectSource, nodeExtractors), joinTree) =
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runWriter $
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flip runReaderT strfyNum $
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processAnnSimpleSelect sourcePrefixes rootFldName permLimitSubQuery annSel
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selectNode = SelectNode nodeExtractors joinTree
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topExtractor =
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asJsonAggExtr jsonAggSelect rootFldAls permLimitSubQuery $
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orderByForJsonAgg selectSource
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arrayNode = MultiRowSelectNode [topExtractor] selectNode
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in prefixNumToAliases $
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generateSQLSelectFromArrayNode selectSource arrayNode $ S.BELit True
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where
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strfyNum = _asnStrfyNum annSel
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rootFldIdentifier = toIdentifier rootFldName
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sourcePrefixes = SourcePrefixes rootFldIdentifier rootFldIdentifier
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rootFldName = FieldName "root"
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rootFldAls = S.Alias $ toIdentifier rootFldName
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