result append: remove the short circuit code

Signed-off-by: Harshit Gangal <harshit@planetscale.com>

go/sqltypes/result.go

@@ -330,17 +330,14 @@ func (result *Result) StripMetadata(incl querypb.ExecuteOptions_IncludedFields)
 // to another result.Note currently it doesn't handle cases like
 // if two results have different fields.We will enhance this function.
 func (result *Result) AppendResult(src *Result) {
-	if src.RowsAffected == 0 && len(src.Rows) == 0 && len(src.Fields) == 0 {
-		return
-	}
-	if result.Fields == nil {
-		result.Fields = src.Fields
-	}
 	result.RowsAffected += src.RowsAffected
 	if src.InsertID != 0 || src.InsertIDChanged {
 		result.InsertID = src.InsertID
 	}
 	result.InsertIDChanged = result.InsertIDChanged || src.InsertIDChanged
+	if result.Fields == nil {
+		result.Fields = src.Fields
+	}
 	result.Rows = append(result.Rows, src.Rows...)
 }
 

go/test/endtoend/utils/cmp.go

@@ -313,3 +313,10 @@ func (mcmp *MySQLCompare) ExecAllowError(query string) (*sqltypes.Result, error)
 	}
 	return vtQr, vtErr
 }
+
+func (mcmp *MySQLCompare) VExplain(query string) {
+	mcmp.t.Helper()
+	vtQr, vtErr := mcmp.VtConn.ExecuteFetch("vexplain plan "+query, 1, true)
+	require.NoError(mcmp.t, vtErr, "[Vitess Error] for query: "+query)
+	fmt.Printf("Vitess VExplain Plan: \n%v\n", vtQr.Rows[0][0].ToString())
+}

go/test/endtoend/vtgate/queries/misc/misc_test.go

@@ -144,6 +144,9 @@ func TestSetAndGetLastInsertID(t *testing.T) {
 			mcmp.Run(name, func(mcmp *utils.MySQLCompare) {
 				mcmp.Exec(query)
 				mcmp.Exec("select last_insert_id()")
+				if mcmp.AsT().Failed() {
+					mcmp.VExplain(query)
+				}
 			})
 		}
 		// we need this value to be not zero, and then we keep changing it so different queries don't interact with each other

go/vt/vttablet/tabletserver/query_executor.go

@@ -1206,9 +1206,9 @@ func (qre *QueryExecutor) execStreamSQL(conn *connpool.PooledConn, isTransaction
 	callBackClosingSpan := func(result *sqltypes.Result) error {
 		defer span.Finish()
 
-		if err := qre.fetchLastInsertID(ctx, conn.Conn, result); err != nil {
-			return err
-		}
+		// if err := qre.fetchLastInsertID(ctx, conn.Conn, result); err != nil {
+		// 	return err
+		// }
 
 		return callback(result)
 	}
@@ -1222,9 +1222,9 @@ func (qre *QueryExecutor) execStreamSQL(conn *connpool.PooledConn, isTransaction
 	// This change will ensure that long-running streaming stateful queries get gracefully shutdown during ServingTypeChange
 	// once their grace period is over.
 	qd := NewQueryDetail(qre.logStats.Ctx, conn.Conn)
-	if err := qre.resetLastInsertIDIfNeeded(ctx, conn.Conn); err != nil {
-		return err
-	}
+	// if err := qre.resetLastInsertIDIfNeeded(ctx, conn.Conn); err != nil {
+	// 	return err
+	// }
 
 	if isTransaction {
 		err := qre.tsv.statefulql.Add(qd)