fix: Mysql should support more data types. #923 (#926)

* fix: Mysql should support more data types. #923

* go fmt

* fix lint issue

* revise according to the review comment

Co-authored-by: Phil Kedy <phil.kedy@gmail.com>
Co-authored-by: Yaron Schneider <yaronsc@microsoft.com>

bindings/mysql/mysql.go

@@ -9,9 +9,11 @@ import (
 	"crypto/tls"
 	"crypto/x509"
 	"database/sql"
+	"database/sql/driver"
 	"encoding/json"
 	"fmt"
 	"io/ioutil"
+	"reflect"
 	"strconv"
 	"time"
 
@@ -203,7 +205,7 @@ func (m *Mysql) query(s string) ([]byte, error) {
 		_ = rows.Err()
 	}()
 
-	result, err := jsonify(rows)
+	result, err := m.jsonify(rows)
 	if err != nil {
 		return nil, errors.Wrapf(err, "error marshalling query result for %s", s)
 	}
@@ -277,7 +279,7 @@ func initDB(url, pemPath string) (*sql.DB, error) {
 	return db, nil
 }
 
-func jsonify(rows *sql.Rows) ([]byte, error) {
+func (m *Mysql) jsonify(rows *sql.Rows) ([]byte, error) {
 	columnTypes, err := rows.ColumnTypes()
 	if err != nil {
 		return nil, err
@@ -285,84 +287,58 @@ func jsonify(rows *sql.Rows) ([]byte, error) {
 
 	var ret []interface{}
 	for rows.Next() {
-		scanArgs := prepareScanArgs(columnTypes)
-		err := rows.Scan(scanArgs...)
+		values := prepareValues(columnTypes)
+		err := rows.Scan(values...)
 		if err != nil {
 			return nil, err
 		}
 
-		r := convertScanArgs(columnTypes, scanArgs)
+		r := m.convert(columnTypes, values)
 		ret = append(ret, r)
 	}
 
 	return json.Marshal(ret)
 }
 
-func convertScanArgs(columnTypes []*sql.ColumnType, scanArgs []interface{}) map[string]interface{} {
+func prepareValues(columnTypes []*sql.ColumnType) []interface{} {
+	types := make([]reflect.Type, len(columnTypes))
+	for i, tp := range columnTypes {
+		types[i] = tp.ScanType()
+	}
+
+	values := make([]interface{}, len(columnTypes))
+	for i := range values {
+		values[i] = reflect.New(types[i]).Interface()
+	}
+
+	return values
+}
+
+func (m *Mysql) convert(columnTypes []*sql.ColumnType, values []interface{}) map[string]interface{} {
 	r := map[string]interface{}{}
 
-	for i, v := range columnTypes {
-		if s, ok := (scanArgs[i]).(*sql.NullString); ok {
-			r[v.Name()] = s.String
+	for i, ct := range columnTypes {
+		value := values[i]
 
-			continue
+		switch v := values[i].(type) {
+		case driver.Valuer:
+			if vv, err := v.Value(); err == nil {
+				value = interface{}(vv)
+			} else {
+				m.logger.Warnf("error to convert value: %v", err)
+			}
+		case *sql.RawBytes:
+			// special case for sql.RawBytes, see https://github.com/go-sql-driver/mysql/blob/master/fields.go#L178
+			switch ct.DatabaseTypeName() {
+			case "VARCHAR", "CHAR":
+				value = string(*v)
+			}
 		}
 
-		if s, ok := (scanArgs[i]).(*sql.NullBool); ok {
-			r[v.Name()] = s.Bool
-
-			continue
+		if value != nil {
+			r[ct.Name()] = value
 		}
-
-		if s, ok := (scanArgs[i]).(*sql.NullInt32); ok {
-			r[v.Name()] = s.Int32
-
-			continue
-		}
-
-		if s, ok := (scanArgs[i]).(*sql.NullInt64); ok {
-			r[v.Name()] = s.Int64
-
-			continue
-		}
-
-		if s, ok := (scanArgs[i]).(*sql.NullFloat64); ok {
-			r[v.Name()] = s.Float64
-
-			continue
-		}
-
-		if s, ok := (scanArgs[i]).(*sql.NullTime); ok {
-			r[v.Name()] = s.Time
-
-			continue
-		}
-
-		// this won't happen since the default switch is sql.NullString
-		r[v.Name()] = scanArgs[i]
 	}
 
 	return r
 }
-
-func prepareScanArgs(columnTypes []*sql.ColumnType) []interface{} {
-	scanArgs := make([]interface{}, len(columnTypes))
-	for i, v := range columnTypes {
-		switch v.DatabaseTypeName() {
-		case "BOOL":
-			scanArgs[i] = new(sql.NullBool)
-		case "INT", "MEDIUMINT", "SMALLINT", "CHAR", "TINYINT":
-			scanArgs[i] = new(sql.NullInt32)
-		case "BIGINT":
-			scanArgs[i] = new(sql.NullInt64)
-		case "DOUBLE", "FLOAT", "DECIMAL":
-			scanArgs[i] = new(sql.NullFloat64)
-		case "DATE", "TIME", "YEAR":
-			scanArgs[i] = new(sql.NullTime)
-		default:
-			scanArgs[i] = new(sql.NullString)
-		}
-	}
-
-	return scanArgs
-}

bindings/mysql/mysql_integration_test.go

@@ -121,7 +121,7 @@ func TestMysqlIntegration(t *testing.T) {
 		assert.True(t, ok)
 		// have to use custom layout to parse timestamp, see this: https://github.com/dapr/components-contrib/pull/615
 		var tt time.Time
-		tt, err = time.Parse("2006-01-02 15:04:05", ts)
+		tt, err = time.Parse("2006-01-02T15:04:05Z", ts)
 		assert.Nil(t, err)
 		t.Logf("time stamp is: %v", tt)
 	})

bindings/mysql/mysql_test.go

@@ -26,7 +26,7 @@ func TestQuery(t *testing.T) {
 		ret, err := m.query(`SELECT * FROM foo WHERE id < 4`)
 		assert.Nil(t, err)
 		t.Logf("query result: %s", ret)
-		assert.Contains(t, string(ret), "\"id\":\"1\"")
+		assert.Contains(t, string(ret), "\"id\":1")
 		var result []interface{}
 		err = json.Unmarshal(ret, &result)
 		assert.Nil(t, err)