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module SQL | |
%default total | |
%access public export | |
data SqlType = BOOLEAN | INTEGER | |
mutual | |
data ColumnExpression : SqlType -> Type where | |
BooleanLiteral : Bool -> ColumnExpression BOOLEAN | |
IntegerLiteral : Int -> ColumnExpression INTEGER | |
SubQueryExpression : | |
(query : SqlQuery a) | |
-> { auto prf : QueryHasExactlyOneColumn query } | |
-> ColumnExpression (getSqlTypeFromQueryWithOneColumn query {prf=prf}) | |
(+) : ColumnExpression INTEGER -> ColumnExpression INTEGER -> ColumnExpression INTEGER | |
(-) : ColumnExpression INTEGER -> ColumnExpression INTEGER -> ColumnExpression INTEGER | |
AnyColumnExpression' : Type | |
AnyColumnExpression' = (sqlType ** ColumnExpression sqlType) | |
data SqlQuery : (result : Type) -> Type where | |
SelectColumn : AnyColumnExpression' -> SqlQuery () | |
Where : ColumnExpression BOOLEAN -> SqlQuery () | |
(>>=) : SqlQuery a -> (a -> SqlQuery b) -> SqlQuery b | |
namespace QueryHasExactlyOneColumn | |
data QueryHasNoColumns : (query : SqlQuery a) -> Type where | |
OkToStartWithWhere : QueryHasNoColumns (Where boolExpression) | |
OkToAppendWhereNoCols : | |
{a : Type} | |
-> {query : SqlQuery a} | |
-> QueryHasNoColumns query | |
-> QueryHasNoColumns (do query; Where boolExpression) | |
data QueryHasExactlyOneColumn : (query : SqlQuery a) -> Type where | |
Start : QueryHasExactlyOneColumn (SelectColumn (sqlType ** columnExpression)) | |
OkToAppendWhere : | |
{a : Type} | |
-> {query : SqlQuery a} | |
-> QueryHasExactlyOneColumn query | |
-> QueryHasExactlyOneColumn (do query; Where boolExpression) | |
OkToAppendSelectToQueryWOColumns : | |
{sqlType : SqlType} | |
-> {a : Type} | |
-> {query : SqlQuery a} | |
-> QueryHasNoColumns query | |
-> QueryHasExactlyOneColumn (do query; SelectColumn (sqlType ** columnExpression)) | |
getSqlTypeFromQueryWithOneColumn : (query : SqlQuery a) -> { auto prf : QueryHasExactlyOneColumn query } -> SqlType | |
getSqlTypeFromQueryWithOneColumn query {prf} = ( | |
case prf of | |
Start {sqlType} => sqlType | |
(OkToAppendWhere {query} prf') => getSqlTypeFromQueryWithOneColumn query {prf=prf'} | |
(OkToAppendSelectToQueryWOColumns {sqlType} prfNoColumns) => sqlType | |
) | |
query : SqlQuery () | |
query = do | |
SelectColumn (_ ** IntegerLiteral 11) | |
Where $ BooleanLiteral True | |
onlyOne : QueryHasExactlyOneColumn SQL.query | |
onlyOne = assert_total $ OkToAppendWhere Start | |
queryType : SqlType | |
queryType = assert_total $ getSqlTypeFromQueryWithOneColumn query | |
subQuery : SqlQuery () | |
subQuery = assert_total $ do | |
SelectColumn (_ ** SubQueryExpression (do SelectColumn (_ ** IntegerLiteral 11);)) | |
onlyOne' : QueryHasExactlyOneColumn SQL.subQuery | |
onlyOne' = Start | |
{- | |
Errors (2) | |
/home/nickolay/workspace/Idris/horn/src/SQL.idr:89:12 | |
Type mismatch between | |
ColumnExpression (getSqlTypeFromQueryWithOneColumn (SelectColumn (INTEGER ** | |
IntegerLiteral 11))) | |
and | |
ColumnExpression INTEGER | |
/home/nickolay/workspace/Idris/horn/src/SQL.idr:63:5 | |
SQL.getSqlTypeFromQueryWithOneColumn is possibly not total due to: SQL.case block in getSqlTypeFromQueryWithOneColumn at /home/nickolay/workspace/Idris/horn/src/SQL.idr:64:14-16 | |
-} |
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