postgres: fix value columns conversion to float when using timeseries query

pkg/tsdb/postgres/postgres.go

@@ -245,16 +245,10 @@ func (e PostgresQueryEndpoint) transformToTimeSeries(query *tsdb.Query, rows *co
 				continue
 			}
 
-			switch columnValue := values[i].(type) {
-			case int64:
-				value = null.FloatFrom(float64(columnValue))
-			case float64:
-				value = null.FloatFrom(columnValue)
-			case nil:
-				value.Valid = false
-			default:
-				return fmt.Errorf("Value column must have numeric datatype, column: %s type: %T value: %v", col, columnValue, columnValue)
+			if value, err = tsdb.ConvertSqlValueColumnToFloat(col, values[i]); err != nil {
+				return err
 			}
+
 			if metricIndex == -1 {
 				metric = col
 			}

pkg/tsdb/postgres/postgres_test.go

@@ -353,12 +353,12 @@ func TestPostgres(t *testing.T) {
 			_, err = sess.InsertMulti(series)
 			So(err, ShouldBeNil)
 
-			Convey("When doing a metric query using epoch (int64) as time column should return metric with time in milliseconds", func() {
+			Convey("When doing a metric query using epoch (int64) as time column and value column (int64) should return metric with time in milliseconds", func() {
 				query := &tsdb.TsdbQuery{
 					Queries: []*tsdb.Query{
 						{
 							Model: simplejson.NewFromAny(map[string]interface{}{
-								"rawSql": `SELECT "timeInt64" as time, "valueOne" FROM metric_values ORDER BY time LIMIT 1`,
+								"rawSql": `SELECT "timeInt64" as time, "timeInt64" FROM metric_values ORDER BY time LIMIT 1`,
 								"format": "time_series",
 							}),
 							RefId: "A",
@@ -375,12 +375,12 @@ func TestPostgres(t *testing.T) {
 				So(queryResult.Series[0].Points[0][1].Float64, ShouldEqual, float64(tInitial.UnixNano()/1e6))
 			})
 
-			Convey("When doing a metric query using epoch (int64 nullable) as time column should return metric with time in milliseconds", func() {
+			Convey("When doing a metric query using epoch (int64 nullable) as time column and value column (int64 nullable) should return metric with time in milliseconds", func() {
 				query := &tsdb.TsdbQuery{
 					Queries: []*tsdb.Query{
 						{
 							Model: simplejson.NewFromAny(map[string]interface{}{
-								"rawSql": `SELECT "timeInt64Nullable" as time, "valueOne" FROM metric_values ORDER BY time LIMIT 1`,
+								"rawSql": `SELECT "timeInt64Nullable" as time, "timeInt64Nullable" FROM metric_values ORDER BY time LIMIT 1`,
 								"format": "time_series",
 							}),
 							RefId: "A",
@@ -397,12 +397,12 @@ func TestPostgres(t *testing.T) {
 				So(queryResult.Series[0].Points[0][1].Float64, ShouldEqual, float64(tInitial.UnixNano()/1e6))
 			})
 
-			Convey("When doing a metric query using epoch (float64) as time column should return metric with time in milliseconds", func() {
+			Convey("When doing a metric query using epoch (float64) as time column and value column (float64) should return metric with time in milliseconds", func() {
 				query := &tsdb.TsdbQuery{
 					Queries: []*tsdb.Query{
 						{
 							Model: simplejson.NewFromAny(map[string]interface{}{
-								"rawSql": `SELECT "timeFloat64" as time, "valueOne" FROM metric_values ORDER BY time LIMIT 1`,
+								"rawSql": `SELECT "timeFloat64" as time, "timeFloat64" FROM metric_values ORDER BY time LIMIT 1`,
 								"format": "time_series",
 							}),
 							RefId: "A",
@@ -419,12 +419,12 @@ func TestPostgres(t *testing.T) {
 				So(queryResult.Series[0].Points[0][1].Float64, ShouldEqual, float64(tInitial.UnixNano()/1e6))
 			})
 
-			Convey("When doing a metric query using epoch (float64 nullable) as time column should return metric with time in milliseconds", func() {
+			Convey("When doing a metric query using epoch (float64 nullable) as time column and value column (float64 nullable) should return metric with time in milliseconds", func() {
 				query := &tsdb.TsdbQuery{
 					Queries: []*tsdb.Query{
 						{
 							Model: simplejson.NewFromAny(map[string]interface{}{
-								"rawSql": `SELECT "timeFloat64Nullable" as time, "valueOne" FROM metric_values ORDER BY time LIMIT 1`,
+								"rawSql": `SELECT "timeFloat64Nullable" as time, "timeFloat64Nullable" FROM metric_values ORDER BY time LIMIT 1`,
 								"format": "time_series",
 							}),
 							RefId: "A",
@@ -441,12 +441,12 @@ func TestPostgres(t *testing.T) {
 				So(queryResult.Series[0].Points[0][1].Float64, ShouldEqual, float64(tInitial.UnixNano()/1e6))
 			})
 
-			Convey("When doing a metric query using epoch (int32) as time column should return metric with time in milliseconds", func() {
+			Convey("When doing a metric query using epoch (int32) as time column and value column (int32) should return metric with time in milliseconds", func() {
 				query := &tsdb.TsdbQuery{
 					Queries: []*tsdb.Query{
 						{
 							Model: simplejson.NewFromAny(map[string]interface{}{
-								"rawSql": `SELECT "timeInt32" as time, "valueOne" FROM metric_values ORDER BY time LIMIT 1`,
+								"rawSql": `SELECT "timeInt32" as time, "timeInt32" FROM metric_values ORDER BY time LIMIT 1`,
 								"format": "time_series",
 							}),
 							RefId: "A",
@@ -463,12 +463,12 @@ func TestPostgres(t *testing.T) {
 				So(queryResult.Series[0].Points[0][1].Float64, ShouldEqual, float64(tInitial.UnixNano()/1e6))
 			})
 
-			Convey("When doing a metric query using epoch (int32 nullable) as time column should return metric with time in milliseconds", func() {
+			Convey("When doing a metric query using epoch (int32 nullable) as time column and value column (int32 nullable) should return metric with time in milliseconds", func() {
 				query := &tsdb.TsdbQuery{
 					Queries: []*tsdb.Query{
 						{
 							Model: simplejson.NewFromAny(map[string]interface{}{
-								"rawSql": `SELECT "timeInt32Nullable" as time, "valueOne" FROM metric_values ORDER BY time LIMIT 1`,
+								"rawSql": `SELECT "timeInt32Nullable" as time, "timeInt32Nullable" FROM metric_values ORDER BY time LIMIT 1`,
 								"format": "time_series",
 							}),
 							RefId: "A",
@@ -485,12 +485,12 @@ func TestPostgres(t *testing.T) {
 				So(queryResult.Series[0].Points[0][1].Float64, ShouldEqual, float64(tInitial.UnixNano()/1e6))
 			})
 
-			Convey("When doing a metric query using epoch (float32) as time column should return metric with time in milliseconds", func() {
+			Convey("When doing a metric query using epoch (float32) as time column and value column (float32) should return metric with time in milliseconds", func() {
 				query := &tsdb.TsdbQuery{
 					Queries: []*tsdb.Query{
 						{
 							Model: simplejson.NewFromAny(map[string]interface{}{
-								"rawSql": `SELECT "timeFloat32" as time, "valueOne" FROM metric_values ORDER BY time LIMIT 1`,
+								"rawSql": `SELECT "timeFloat32" as time, "timeFloat32" FROM metric_values ORDER BY time LIMIT 1`,
 								"format": "time_series",
 							}),
 							RefId: "A",
@@ -507,12 +507,12 @@ func TestPostgres(t *testing.T) {
 				So(queryResult.Series[0].Points[0][1].Float64, ShouldEqual, float64(float64(float32(tInitial.Unix())))*1e3)
 			})
 
-			Convey("When doing a metric query using epoch (float32 nullable) as time column should return metric with time in milliseconds", func() {
+			Convey("When doing a metric query using epoch (float32 nullable) as time column and value column (float32 nullable) should return metric with time in milliseconds", func() {
 				query := &tsdb.TsdbQuery{
 					Queries: []*tsdb.Query{
 						{
 							Model: simplejson.NewFromAny(map[string]interface{}{
-								"rawSql": `SELECT "timeFloat32Nullable" as time, "valueOne" FROM metric_values ORDER BY time LIMIT 1`,
+								"rawSql": `SELECT "timeFloat32Nullable" as time, "timeFloat32Nullable" FROM metric_values ORDER BY time LIMIT 1`,
 								"format": "time_series",
 							}),
 							RefId: "A",