integration: add grafana queries to go integration

SUPPORTED_CLIENTS.md

@@ -16,6 +16,7 @@ These are the clients we actively test against to check are compatible with go-m
   - [mariadb-java-client](#mariadb-java-client)
 - Go
   - [go-mysql-driver/mysql](#go-mysql-driver-mysql)
+- Grafana
 
 ## Example client usage
 
@@ -129,7 +130,7 @@ namespace something
         public async Task DoQuery()
         {
             var connectionString = "server=127.0.0.1;user id=user;password=pass;port=3306;database=dbname;";
-            
+
             using (var conn = new MySqlConnection(connectionString))
             {
                 await conn.OpenAsync();

_integration/go/mysql_test.go

@@ -2,13 +2,16 @@ package testmysql
 
 import (
 	"database/sql"
+	"reflect"
 	"testing"
 
 	_ "github.com/go-sql-driver/mysql"
 )
 
+const connectionString = "user:pass@tcp(127.0.0.1:3306)/test"
+
 func TestMySQL(t *testing.T) {
-	db, err := sql.Open("mysql", "user:pass@tcp(127.0.0.1:3306)/test")
+	db, err := sql.Open("mysql", connectionString)
 	if err != nil {
 		t.Fatalf("can't connect to mysql: %s", err)
 	}
@@ -54,3 +57,92 @@ func TestMySQL(t *testing.T) {
 		}
 	}
 }
+
+func TestGrafana(t *testing.T) {
+	db, err := sql.Open("mysql", connectionString)
+	if err != nil {
+		t.Fatalf("can't connect to mysql: %s", err)
+	}
+
+	tests := []struct {
+		query    string
+		expected [][]string
+	}{
+		{
+			`SELECT 1`,
+			[][]string{{"1"}},
+		},
+		{
+			`select @@version_comment limit 1`,
+			[][]string{{"NULL"}},
+		},
+		{
+			`describe table mytable`,
+			[][]string{
+				{"name", "TEXT"},
+				{"email", "TEXT"},
+				{"phone_numbers", "JSON"},
+				{"created_at", "TIMESTAMP"},
+			},
+		},
+		{
+			`select count(*) from mytable where created_at ` +
+				`between '2000-01-01T00:00:00Z' and '2999-01-01T00:00:00Z'`,
+			[][]string{{"4"}},
+		},
+	}
+
+	for _, c := range tests {
+		rs, err := db.Query(c.query)
+		if err != nil {
+			t.Fatalf("unable to execute query: %s", err)
+		}
+
+		result := getResult(t, rs)
+
+		if !reflect.DeepEqual(result, c.expected) {
+			t.Fatalf("rows do not match, expected: %v, got: %v", c.expected, result)
+		}
+	}
+}
+
+func getResult(t *testing.T, rs *sql.Rows) [][]string {
+	t.Helper()
+
+	columns, err := rs.Columns()
+	if err != nil {
+		t.Fatalf("unable to get columns: %s", err)
+	}
+
+	var result [][]string
+	p := make([]interface{}, len(columns))
+
+	for rs.Next() {
+		row := make([]interface{}, len(columns))
+		for i := range row {
+			p[i] = &row[i]
+		}
+
+		err = rs.Scan(p...)
+		if err != nil {
+			t.Fatalf("could not retrieve row: %s", err)
+		}
+
+		result = append(result, getStringSlice(row))
+	}
+
+	return result
+}
+
+func getStringSlice(row []interface{}) []string {
+	rowStrings := make([]string, len(row))
+	for i, r := range row {
+		if r == nil {
+			rowStrings[i] = "NULL"
+		} else {
+			rowStrings[i] = string(r.([]uint8))
+		}
+	}
+
+	return rowStrings
+}