more fixes

Author: James Cor

enginetest/queries/queries.go

@@ -10232,6 +10232,12 @@ from typestable`,
 			{"981228896.000000"},
 		},
 	},
+	{
+		Query:    "select unix_timestamp('2001-02-03 12:34:56.1234567');",
+		Expected: []sql.Row{
+			{"981228896.123457"},
+		},
+	},
 }
 
 var KeylessQueries = []QueryTest{

sql/expression/function/date.go

@@ -484,6 +484,9 @@ func NewUnixTimestamp(args ...sql.Expression) (sql.Expression, error) {
 			dateStr = strings.TrimSpace(dateStr[idx:])
 			scale := uint8(len(dateStr) - 1)
 			if scale > 0 {
+				if scale > 6 {
+					scale = 6
+				}
 				typ, tErr := types.CreateDecimalType(19, scale)
 				if tErr != nil {
 					return nil, tErr

sql/types/datetime.go

@@ -198,10 +198,10 @@ func ConvertToTime(v interface{}, t datetimeType) (time.Time, error) {
 		return zeroTime, nil
 	}
 
-	// Truncate the date to the precision of this type
+	// Round the date to the precision of this type
 	truncationDuration := time.Second
 	truncationDuration /= time.Duration(precisionConversion[t.precision])
-	res = res.Truncate(truncationDuration)
+	res = res.Round(truncationDuration)
 
 	switch t.baseType {
 	case sqltypes.Date: