database/sql: add support for multiple result sets

Many database systems allow returning multiple result sets
in a single query. This can be useful when dealing with many
intermediate results on the server and there is a need
to return more then one arity of data to the client.

Fixes #12382

Change-Id: I480a9ac6dadfc8743e0ba8b6d868ccf8442a9ca1
Reviewed-on: https://go-review.googlesource.com/30592
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

1 files changed, 16 insertions, 0 deletions

diff --git a/src/database/sql/driver/driver.go b/src/database/sql/driver/driver.go
index ccc283d373..b3d83f3ff4 100644
--- a/src/database/sql/driver/driver.go
+++ b/src/database/sql/driver/driver.go
@@ -213,6 +213,22 @@ type Rows interface {
 	Next(dest []Value) error
 }
 
+// RowsNextResultSet extends the Rows interface by providing a way to signal
+// the driver to advance to the next result set.
+type RowsNextResultSet interface {
+	Rows
+
+	// HasNextResultSet is called at the end of the current result set and
+	// reports whether there is another result set after the current one.
+	HasNextResultSet() bool
+
+	// NextResultSet advances the driver to the next result set even
+	// if there are remaining rows in the current result set.
+	//
+	// NextResultSet should return io.EOF when there are no more result sets.
+	NextResultSet() error
+}
+
 // Tx is a transaction.
 type Tx interface {
 	Commit() error