Merge pull request #212 from duckdb/f-sql

R/cpp11.R

@@ -156,6 +156,10 @@ rapi_rel_set_symdiff <- function(rel_a, rel_b) {
   .Call(`_duckdb_rapi_rel_set_symdiff`, rel_a, rel_b)
 }
 
+rapi_rel_from_sql <- function(con, sql) {
+  .Call(`_duckdb_rapi_rel_from_sql`, con, sql)
+}
+
 rapi_rel_from_table <- function(con, schema_name, table_name) {
   .Call(`_duckdb_rapi_rel_from_table`, con, schema_name, table_name)
 }

R/relational.R

@@ -148,7 +148,7 @@ rel_aggregate <- rapi_rel_aggregate
 #' Lazily reorder a DuckDB relation object
 #' @param rel the DuckDB relation object
 #' @param orders a list of DuckDB expressions to order by
-#' @param ascending a vector of boolean values describing sort order of expressions. True for ascending. 
+#' @param ascending a vector of boolean values describing sort order of expressions. True for ascending.
 #' @return the now aggregated `duckdb_relation` object
 #' @noRd
 #' @examples
@@ -163,7 +163,7 @@ rel_order <- function(rel, orders, ascending = NULL) {
   if (length(orders) != length(ascending)) {
     stop("length of ascending must equal length of orders")
   }
-  
+
   return(rapi_rel_order(rel, orders, ascending))
 }
 
@@ -385,6 +385,18 @@ rel_to_sql <- rapi_rel_to_sql
 
 
 
+#' Create a duckdb table relation from a table name
+#' @param sql An SQL query
+#' @return a duckdb relation
+#' @noRd
+#' @examples
+#' con <- DBI::dbConnect(duckdb())
+#' DBI::dbWriteTable(con, "mtcars", mtcars)
+#' rel <- rel_from_sql(con, "SELECT * FROM mtcars")
+rel_from_sql <- function(con, sql) {
+    rapi_rel_from_sql(con@conn_ref, sql)
+}
+
 #' Create a duckdb table relation from a table name
 #' @param table the table name
 #' @return a duckdb relation
@@ -393,7 +405,7 @@ rel_to_sql <- rapi_rel_to_sql
 #' con <- DBI::dbConnect(duckdb())
 #' DBI::dbWriteTable(con, "mtcars", mtcars)
 #' rel <- rel_from_table(con, "mtcars")
-rel_from_table <- function(con, table_name, schema_name="MAIN") {
+rel_from_table <- function(con, table_name, schema_name = "MAIN") {
     rapi_rel_from_table(con@conn_ref, schema_name, table_name)
 }
 

src/cpp11.cpp

@@ -287,6 +287,13 @@ extern "C" SEXP _duckdb_rapi_rel_set_symdiff(SEXP rel_a, SEXP rel_b) {
   END_CPP11
 }
 // relational.cpp
+SEXP rapi_rel_from_sql(duckdb::conn_eptr_t con, const std::string sql);
+extern "C" SEXP _duckdb_rapi_rel_from_sql(SEXP con, SEXP sql) {
+  BEGIN_CPP11
+    return cpp11::as_sexp(rapi_rel_from_sql(cpp11::as_cpp<cpp11::decay_t<duckdb::conn_eptr_t>>(con), cpp11::as_cpp<cpp11::decay_t<const std::string>>(sql)));
+  END_CPP11
+}
+// relational.cpp
 SEXP rapi_rel_from_table(duckdb::conn_eptr_t con, const std::string schema_name, const std::string table_name);
 extern "C" SEXP _duckdb_rapi_rel_from_table(SEXP con, SEXP schema_name, SEXP table_name) {
   BEGIN_CPP11
@@ -451,6 +458,7 @@ static const R_CallMethodDef CallEntries[] = {
     {"_duckdb_rapi_rel_filter",              (DL_FUNC) &_duckdb_rapi_rel_filter,              2},
     {"_duckdb_rapi_rel_from_altrep_df",      (DL_FUNC) &_duckdb_rapi_rel_from_altrep_df,      3},
     {"_duckdb_rapi_rel_from_df",             (DL_FUNC) &_duckdb_rapi_rel_from_df,             3},
+    {"_duckdb_rapi_rel_from_sql",            (DL_FUNC) &_duckdb_rapi_rel_from_sql,            2},
     {"_duckdb_rapi_rel_from_table",          (DL_FUNC) &_duckdb_rapi_rel_from_table,          3},
     {"_duckdb_rapi_rel_from_table_function", (DL_FUNC) &_duckdb_rapi_rel_from_table_function, 4},
     {"_duckdb_rapi_rel_join",                (DL_FUNC) &_duckdb_rapi_rel_join,                5},

src/relational.cpp

@@ -490,12 +490,20 @@ static SEXP result_to_df(duckdb::unique_ptr<QueryResult> res) {
 	return make_external_prot<RelationWrapper>("duckdb_relation", prot, symdiff);
 }
 
+[[cpp11::register]] SEXP rapi_rel_from_sql(duckdb::conn_eptr_t con, const std::string sql) {
+	if (!con || !con.get() || !con->conn) {
+		stop("rel_from_table: Invalid connection");
+	}
+	auto rel = con->conn->RelationFromQuery(sql);
+	cpp11::writable::list prot = {};
+	return make_external_prot<RelationWrapper>("duckdb_relation", prot, std::move(rel));
+}
+
 [[cpp11::register]] SEXP rapi_rel_from_table(duckdb::conn_eptr_t con, const std::string schema_name,
                                              const std::string table_name) {
 	if (!con || !con.get() || !con->conn) {
 		stop("rel_from_table: Invalid connection");
 	}
-	auto desc = make_uniq<TableDescription>();
 	auto rel = con->conn->Table(schema_name, table_name);
 	cpp11::writable::list prot = {};
 	return make_external_prot<RelationWrapper>("duckdb_relation", prot, std::move(rel));