Updated row.err usage

Author: MichaelS11

README.md

@@ -21,4 +21,18 @@ https://godoc.org/github.com/MichaelS11/go-cql-driver#example-package--SqlSelect
 
 ## Important note:
 
-When calling QueryContext or Query make sure to close the returned rows and check the error. Often an error will only show up after rows is closed.
+When done with rows from QueryContext or Query, make sure to check errors from Close and Err
+```go
+	err = rows.Close()
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+	cancel()
+
+	err = rows.Err()
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+```

cqlSql_test.go

@@ -170,6 +170,10 @@ func TestSqlInsertUpdateSelectDelete(t *testing.T) {
 		t.Fatal("Close error: ", err)
 	}
 	cancel()
+	err = rows.Err()
+	if err != nil {
+		t.Fatal("Err error: ", err)
+	}
 
 	// insert two
 	ctx, cancel = context.WithTimeout(context.Background(), TimeoutValid)
@@ -212,6 +216,10 @@ func TestSqlInsertUpdateSelectDelete(t *testing.T) {
 		t.Fatal("Close error: ", err)
 	}
 	cancel()
+	err = rows.Err()
+	if err != nil {
+		t.Fatal("Err error: ", err)
+	}
 
 	// update two
 	ctx, cancel = context.WithTimeout(context.Background(), TimeoutValid)
@@ -254,6 +262,10 @@ func TestSqlInsertUpdateSelectDelete(t *testing.T) {
 		t.Fatal("Close error: ", err)
 	}
 	cancel()
+	err = rows.Err()
+	if err != nil {
+		t.Fatal("Err error: ", err)
+	}
 
 	// delete two
 	ctx, cancel = context.WithTimeout(context.Background(), TimeoutValid)
@@ -283,6 +295,10 @@ func TestSqlInsertUpdateSelectDelete(t *testing.T) {
 		t.Fatal("Close error: ", err)
 	}
 	cancel()
+	err = rows.Err()
+	if err != nil {
+		t.Fatal("Err error: ", err)
+	}
 
 	// delete two
 	ctx, cancel = context.WithTimeout(context.Background(), TimeoutValid)
@@ -305,6 +321,10 @@ func TestSqlInsertUpdateSelectDelete(t *testing.T) {
 		t.Fatal("QueryContext no error")
 	}
 	cancel()
+	err = rows.Err()
+	if err != nil {
+		t.Fatal("Err error: ", err)
+	}
 
 	ctx, cancel = context.WithTimeout(context.Background(), TimeoutValid)
 	rows, err = db.QueryContext(ctx, "select int_data from "+KeyspaceName+"."+TableName+" where int_data = ?")
@@ -315,6 +335,10 @@ func TestSqlInsertUpdateSelectDelete(t *testing.T) {
 		t.Fatal("QueryContext no error")
 	}
 	cancel()
+	err = rows.Err()
+	if err != nil {
+		t.Fatal("Err error: ", err)
+	}
 
 	err = db.Close()
 	if err != nil {
@@ -379,6 +403,10 @@ func TestSqlSelectLoop(t *testing.T) {
 			t.Fatal("Close error: ", err)
 		}
 		cancel()
+		err = rows.Err()
+		if err != nil {
+			t.Fatal("Err error: ", err)
+		}
 	}
 
 	err = db.Close()
@@ -433,6 +461,10 @@ func TestSqTruncate(t *testing.T) {
 		t.Fatal("Close error: ", err)
 	}
 	cancel()
+	err = rows.Err()
+	if err != nil {
+		t.Fatal("Err error: ", err)
+	}
 
 	err = db.Close()
 	if err != nil {

exampleSqlGo110_test.go

@@ -81,7 +81,12 @@ func Example_sqlConnector() {
 		fmt.Println("Close error is not nil:", err)
 		return
 	}
-	cancel()
+
+	err = rows.Err()
+	if err != nil {
+		fmt.Println("Err error is not nil:", err)
+		return
+	}
 
 	err = db.Close()
 	if err != nil {

exampleSql_test.go

@@ -75,7 +75,12 @@ func Example_sqlSelect() {
 		fmt.Println("Close error is not nil:", err)
 		return
 	}
-	cancel()
+
+	err = rows.Err()
+	if err != nil {
+		fmt.Println("Err error is not nil:", err)
+		return
+	}
 
 	err = db.Close()
 	if err != nil {
@@ -166,7 +171,12 @@ func Example_sqlStatement() {
 		fmt.Println("Close error is not nil:", err)
 		return
 	}
-	cancel()
+
+	err = rows.Err()
+	if err != nil {
+		fmt.Println("Err error is not nil:", err)
+		return
+	}
 
 	err = db.Close()
 	if err != nil {

rows_test.go

@@ -19,11 +19,11 @@ func TestRowsColumns(t *testing.T) {
 	if columns[0] != "cql_version" {
 		t.Fatalf("Columns[0] - received: %v - expected: %v ", columns[0], "cql_version")
 	}
-
 	err := rows.Close()
 	if err != nil {
 		t.Fatalf("Close error - received: %v - expected: %v ", err, nil)
 	}
+
 	err = stmt.Close()
 	if err != nil {
 		t.Fatalf("Close error - received: %v - expected: %v ", err, nil)
@@ -72,11 +72,11 @@ func TestRowsNext(t *testing.T) {
 	if len(dest) != 0 {
 		t.Fatalf("Next len - received: %v - expected: %v ", len(dest), 1)
 	}
-
 	err = rows.Close()
 	if err != nil {
 		t.Fatalf("Close error - received: %v - expected: %v ", err, nil)
 	}
+
 	err = stmt.Close()
 	if err != nil {
 		t.Fatalf("Close error - received: %v - expected: %v ", err, nil)