infoschema: fix default NUMBER_SCALE value of float type #7602

imtbkcat · 2018-09-04T07:31:47Z

What problem does this PR solve?

Fix wrong value for default numberScale value for float and double type.

Test Case:

create table floatschema(a float, b double(7, 3));
select NUMERIC_SCALE from information_schema.COLUMNS where table_name='floatschema';

MySQL:

mysql> select NUMERIC_SCALE from information_schema.COLUMNS where 
table_name='floatschema';
+---------------+
| NUMERIC_SCALE |
+---------------+
|          NULL |
|             3 |
+---------------+
2 rows in set (0.01 sec)

TiDB:

+----------------------+
| NUMERIC_SCALE        |
+----------------------+
| 18446744073709551615 |
|                    3 |
+----------------------+
2 rows in set (0.01 sec)

This is because the default value of NUMERIC_SCALE for float and double type is -1, but NUMERIC_SCALE is a UNSIGNED LONG.

What is changed and how it works?

add code to make NUMERIC_SCALE same as MySQL.

Check List

Tests

Unit test

Code changes

Has exported variable/fields change

Side effects

-No

jackysp · 2018-09-04T07:34:09Z

infoschema/tables.go

@@ -1006,24 +1010,24 @@ func dataForTableConstraints(schemas []*model.DBInfo) [][]types.Datum {
 func dataForPseudoProfiling() [][]types.Datum {
 	var rows [][]types.Datum
 	row := types.MakeDatums(
-		0,                      // QUERY_ID


Please update your golang version to 1.11.

jackysp · 2018-09-04T07:34:12Z

infoschema/tables.go

@@ -1006,24 +1010,24 @@ func dataForTableConstraints(schemas []*model.DBInfo) [][]types.Datum {
 func dataForPseudoProfiling() [][]types.Datum {
 	var rows [][]types.Datum
 	row := types.MakeDatums(
-		0,                      // QUERY_ID


Please update your golang version to 1.11, then format again.

imtbkcat · 2018-09-04T08:06:47Z

PTAL @jackysp

imtbkcat · 2018-09-04T08:09:23Z

/run-all-tests

shenli · 2018-09-05T07:49:37Z

@imtbkcat Please fix the CI.

imtbkcat · 2018-09-10T01:26:37Z

/run-all-tests

imtbkcat · 2018-09-10T01:55:58Z

@shenli ok.

lysu · 2018-09-10T02:38:23Z