diff options
Diffstat (limited to 'lib/expression/query.ml')
| -rw-r--r-- | lib/expression/query.ml | 50 |
1 files changed, 31 insertions, 19 deletions
diff --git a/lib/expression/query.ml b/lib/expression/query.ml index 5bd914a..89c9e0a 100644 --- a/lib/expression/query.ml +++ b/lib/expression/query.ml @@ -1,22 +1,20 @@ -(** - This module create an sql query from an expression. - *) +(** This module create an sql query from an expression. *) open StdLabels -(** This type is used in the query builder (see [query_of_expression] just - below in order to tell if we need to bind the parameters in the query, or - if we can use plain literal as is (with some risk at the execution time. *) +(** This type is used in the query builder (see [query_of_expression] just below + in order to tell if we need to bind the parameters in the query, or if we + can use plain literal as is (with some risk at the execution time. *) type _ binded_query = | BindParam : ImportCSV.DataType.t Queue.t binded_query | NoParam : unit binded_query module QueryParameter = struct - (** Internaly, we need to keep a different type for the Literal chunks - (which requires to be quoted), and raw (which should be given as is to the - sql engine) + (** Internaly, we need to keep a different type for the Literal chunks (which + requires to be quoted), and raw (which should be given as is to the sql + engine) - The Raw can be generated from both BindParam or NoParam queries. *) + The Raw can be generated from both BindParam or NoParam queries. *) type t = | Literal | Queue of ImportCSV.DataType.t Queue.t @@ -28,10 +26,10 @@ module QueryParameter = struct | Literal -> Raw Literal | Queue q -> Raw (Queue q) - (** Nest the parameter in order to use it inside another function call. + (** Nest the parameter in order to use it inside another function call. - The rule is to get out of the Raw mode as soon as we dive into another - one function. *) + The rule is to get out of the Raw mode as soon as we dive into another one + function. *) let nest : t -> t = function | Raw t -> t | other -> other @@ -54,8 +52,8 @@ module Query = TypeBuilder.Make (struct let () = x formatter ~nested in Format.pp_print_flush formatter () - (** Unify an external reference with a given type, using the COALESCE - function *) + (** Unify an external reference with a given type, using the COALESCE function + *) let unify : with_:Type_of.t -> nested:QueryParameter.t -> @@ -139,8 +137,8 @@ module Query = TypeBuilder.Make (struct (fun f v -> (snd v) f ~nested)) formatter expression - (** Format the partition expression. This function is used internally and - only form the expression inside the clause. *) + (** Format the partition expression. This function is used internally and only + form the expression inside the clause. *) let group_windows : QueryParameter.t -> Format.formatter -> @@ -311,12 +309,26 @@ module Query = TypeBuilder.Make (struct | Upper | Trim -> Format.fprintf formatter "%s(%a)" (T.name_of_function name) (print_expression nested') expressions + | Cmp -> ( + (* Transform the CMP operator into two IIF, one for the equality, and a + second one for the comparaison *) + match expressions with + | [ pred1; pred2; lt; eq; gt ] -> + let eq_expr = + (ImportDataTypes.Types.Bool, boperator T.Equal pred1 pred2 type_of) + and gt_expr = + (ImportDataTypes.Types.Bool, boperator T.GT pred1 pred2 type_of) + (* There is nothing for LT, it’s just the remaining case *) + in + funct "IIF" + [ eq_expr; eq; (fst gt, funct "IIF" [ gt_expr; gt; lt ] type_of) ] + type_of ~nested formatter + | _ -> raise Not_found) end) module M = Sym.M (Query) -let query_of_expression : - type b. +let query_of_expression : type b. b binded_query -> Format.formatter -> (Format.formatter -> 'a -> unit) -> |