graphql-engine/server/src-lib/Hasura/Backends/Postgres/Translate/Column.hs
Evie Ciobanu 9337edf096 Evie/postgres/module docs
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/3563
GitOrigin-RevId: e35aafbd210d526ed53db7088e1a47f89f0b9c44
2022-02-08 09:25:35 +00:00

41 lines
1.4 KiB
Haskell

-- | Postgres Translate Column
--
-- Translate column values to Postgres-specific SQL expressions.
module Hasura.Backends.Postgres.Translate.Column
( toTxtValue,
toJSONableExp,
)
where
import Hasura.Backends.Postgres.SQL.DML
import Hasura.Backends.Postgres.SQL.Types
import Hasura.Backends.Postgres.SQL.Value
import Hasura.Backends.Postgres.Types.Column
import Hasura.Prelude
import Hasura.RQL.Types.Column
import Hasura.SQL.Backend
toTxtValue :: ColumnValue ('Postgres pgKind) -> SQLExp
toTxtValue ColumnValue {..} =
withTyAnn ty . withConstructorFn ty $ txtEncoder cvValue
where
ty = unsafePGColumnToBackend cvType
-- | Formats each columns to appropriate SQL expression
toJSONableExp :: Bool -> ColumnType ('Postgres pgKind) -> Bool -> SQLExp -> SQLExp
toJSONableExp stringifyNum colType asText expression
-- If its a numeric column greater than a 32-bit integer, we have to stringify it as JSON spec doesn't support >32-bit integers
| asText || (isScalarColumnWhere isBigNum colType && stringifyNum) =
expression `SETyAnn` textTypeAnn
-- If the column is either a `Geometry` or `Geography` then apply the `ST_AsGeoJSON` function to convert it into GeoJSON format
| isScalarColumnWhere isGeoType colType =
SEFnApp
"ST_AsGeoJSON"
[ expression,
SEUnsafe "15", -- max decimal digits
SEUnsafe "4" -- to print out crs
]
Nothing
`SETyAnn` jsonTypeAnn
| otherwise = expression