From 6b377719c10d5ab3343fd5221f99a4a21008e25a Mon Sep 17 00:00:00 2001
From: Sébastien Dailly <sebastien@dailly.me>
Date: Thu, 14 Mar 2024 08:26:58 +0100
Subject: Initial commit

---
 lib/sql/db.mli | 106 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 106 insertions(+)
 create mode 100644 lib/sql/db.mli

(limited to 'lib/sql/db.mli')

diff --git a/lib/sql/db.mli b/lib/sql/db.mli
new file mode 100644
index 0000000..465b159
--- /dev/null
+++ b/lib/sql/db.mli
@@ -0,0 +1,106 @@
+module Syntax = ImportConf.Syntax
+
+type 'a t
+type 'a result = ('a, exn) Result.t
+
+val with_db : string -> ('a t -> unit result) -> unit result
+
+val check_table_schema : 'a t -> ImportAnalyser.Dependency.t -> bool result
+(** Check if a table with the same structure already exists in the database. 
+
+    This query allow to reuse the same data without reloading the file if
+    nothing changed. *)
+
+val create_table : 'a t -> ImportAnalyser.Dependency.t -> unit result
+(** [create_table db name] will create a new table in the
+    db with the given name, and the columns from the configuration (see
+    [ImportAnalyser.Query.create_table])
+
+    Any previous table with the same name will be deleted. *)
+
+val prepare_insert : 'a t -> ImportAnalyser.Dependency.t -> Sqlite3.stmt result
+(** Create a statement to use in an insert. 
+    [prepare_insert db table] will prepare a statement for inserting
+    the columns at the given index. *)
+
+val finalize : Sqlite3.stmt -> unit result
+(** Finalize the statement. The function shall be called once each insert are
+    done, or after an error in the insert. *)
+
+val reset : Sqlite3.stmt -> unit result
+
+val eval_key :
+  'a t ->
+  Sqlite3.stmt option ->
+  ImportAnalyser.Dependency.key list ->
+  (int * ImportCSV.DataType.t) list ->
+  (Sqlite3.stmt option * Sqlite3.Data.t list) result
+(** Evaluate the keys in sqlite and get the results. 
+
+    The function is intended to check if the values are null before inserting
+    them in a batch *)
+
+val insert :
+  'a t ->
+  Sqlite3.stmt ->
+  id:int ->
+  (int * ImportCSV.DataType.t) list ->
+  unit result
+(** Insert a new row in the database. 
+
+ [insert db ~id statement values] will add a new row in the given table with
+ [id]. The columns are identified with their index number (there is a
+ difference by one with the column number)
+
+ Thanks to SQLite Flexible Typing (https://www.sqlite.org/flextypegood.html)
+ each column can contain values typed differently which is how the spreadsheet
+ also works. 
+
+ This function is expected to be run inside a transaction. *)
+
+val begin_transaction : 'a t -> unit result
+val commit : 'a t -> unit result
+val rollback : 'a t -> unit result
+
+val query :
+  f:
+    ((ImportDataTypes.Path.t ImportExpression.T.t * ImportCSV.DataType.t) array ->
+    unit) ->
+  'a t ->
+  Syntax.t ->
+  unit result
+(** This one the most important function from the application. The function
+    will transform the configuration into an sql query and will fetch the
+    result from the sqlite engine. 
+
+    The function [f] given in argument will be called for each line
+
+    *)
+
+val create_view : 'a t -> Syntax.t -> unit result
+(** Create a view which represent the result *)
+
+val check_foreign :
+  f:((string * ImportCSV.DataType.t) array -> unit) ->
+  'a t ->
+  Syntax.t ->
+  Syntax.extern ->
+  unit result
+
+val clear_duplicates :
+  f:((string * ImportCSV.DataType.t) array -> unit) ->
+  'a t ->
+  ImportDataTypes.Table.t ->
+  ImportAnalyser.Dependency.key list ->
+  unit result
+(** Remove all duplicated keys in the table by setting them to NULL. *)
+
+val insert_header :
+  'a t ->
+  ImportDataTypes.Table.t ->
+  (int * ImportCSV.DataType.t) array ->
+  unit T.result
+
+val query_headers :
+  'a t -> ImportDataTypes.Table.t -> ImportCSV.DataType.t array T.result
+(** Get all the headers from the database (used or not) *)
-- 
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