Allow RETURNING on INSERT

Author: aarroyoc

README.md

@@ -45,6 +45,7 @@ Items of the DSL:
 * `fetch_first(N, type)` - equivalent to `FETCH FIRST N ROWS type`. Type can be `only (ONLY)` or `with_ties (WITH TIES)`.
 * `insert_into(table, [col1, col2,...])` - equivalent to `INSERT INTO table (col1, col2, ...)`. Must be followed by `values`.
 * `values(val1, val2, ...)` - equivalent to `VALUES (val1, val2, ...)`. Strings here are escaped so it's **safe**.
+* `returning(col1, col2, ...)` equivalent to `RETURNING col1, col2`.
 * `update(table)` - equivalent to `UPDATE table`. Must be followed by `set`
 * `set(Sets)` - equivalent to `SET Col1 = Val1, ...`. Similar to WHERE but only = is allowed. Optionally, you can add a `where+` after a `set`.
 * `delete(table)` - equivalent to `DELETE table`. Must be followed by `where`.
@@ -114,4 +115,4 @@ test :-
     postgresql:sql(Connection, [update(test_table), set(name = "test2"), where(id = 1)], data([])),
     postgresql:sql(Connection, [select(id, name), from(test_table), where(name = "test")], Rows2),
     Rows2 = data([]).
-```
+```

sql_query.pl

@@ -269,13 +269,26 @@
     ") ",
     sql_query_insert_values(Values, Vars).
 
+sql_query_insert_values([Values0|Next], Vars) -->
+    { Values0 =.. [values|Values] },
+    "VALUES (",
+    { values_args(Values, Args, [], Vars) },
+    quoted_comma_separated_list(Args),
+    ")",
+    sql_query_insert_returning(Next).
+
 sql_query_insert_values([Values0], Vars) -->
     { Values0 =.. [values|Values] },
     "VALUES (",
     { values_args(Values, Args, [], Vars) },
     quoted_comma_separated_list(Args),
     ")".
 
+sql_query_insert_returning([Returning0]) -->
+    { Returning0 =.. [returning|Columns] },
+    "RETURNING ",
+    quoted_comma_separated_list(Columns).
+
 values_args([], [], X, X).
 values_args([Value|Values], [Arg|Args], Vars0, Vars) :-
     sql_var(Value, Arg, Vars0, Vars1),

tests.lgt

@@ -166,9 +166,9 @@
 	postgresql:sql(Connection, [insert_into(country, [iso_code, name]), values("PT", "Portugal")], data([])),
 	postgresql:sql(Connection, [insert_into(famous, [name, country, year]), values("Miguel de Cervantes", "ES", 1547)], data([])),
 	postgresql:sql(Connection, [insert_into(famous, [name, country, year]), values("Magallanes", "PT", 1480)], data([])),
-	postgresql:sql(Connection, [insert_into(famous, [name, country, year]), values("Picasso", "ES", 1881)], data([])),
+	postgresql:sql(Connection, [insert_into(famous, [name, country, year]), values("Picasso", "ES", 1881), returning(name, country)], data([["Picasso", "ES"]])),
 	postgresql:sql(Connection, [select('famous.name','country.name'),from(famous),join(country),on('famous.country' = 'country.iso_code'),where((year > 1500,year < 2000)),order_by(asc(year))], Result),
 	Result = data([["Miguel de Cervantes", "España"], ["Picasso", "España"]]).
 
 
-:- end_object.
+:- end_object.