Vitess online ddl: modifyint column from textual to non-textual, igno…

…re character set conversion on target (#10116)

Signed-off-by: Shlomi Noach <[email protected]>

go/test/endtoend/onlineddl/vrepl_suite/testdata/utf8-to-int/alter

@@ -0,0 +1 @@
+modify column t int not null default '0'

go/test/endtoend/onlineddl/vrepl_suite/testdata/utf8-to-int/create.sql

@@ -0,0 +1,21 @@
+drop table if exists onlineddl_test;
+create table onlineddl_test (
+  id int auto_increment,
+  t varchar(128) charset utf8 collate utf8_general_ci,
+  primary key(id)
+) auto_increment=1;
+
+drop event if exists onlineddl_test;
+delimiter ;;
+create event onlineddl_test
+  on schedule every 1 second
+  starts current_timestamp
+  ends current_timestamp + interval 60 second
+  on completion not preserve
+  enable
+  do
+begin
+  insert into onlineddl_test values (null, 11);
+  insert into onlineddl_test values (null, '13');
+  insert into onlineddl_test values (null, '17');
+end ;;

go/test/endtoend/onlineddl/vrepl_suite/testdata/utf8mb4-to-int/alter

@@ -0,0 +1 @@
+modify column t int not null default '0'

go/test/endtoend/onlineddl/vrepl_suite/testdata/utf8mb4-to-int/create.sql

@@ -0,0 +1,21 @@
+drop table if exists onlineddl_test;
+create table onlineddl_test (
+  id int auto_increment,
+  t varchar(128) COLLATE utf8mb4_unicode_ci NOT NULL DEFAULT '',
+  primary key(id)
+) auto_increment=1;
+
+drop event if exists onlineddl_test;
+delimiter ;;
+create event onlineddl_test
+  on schedule every 1 second
+  starts current_timestamp
+  ends current_timestamp + interval 60 second
+  on completion not preserve
+  enable
+  do
+begin
+  insert into onlineddl_test values (null, 11);
+  insert into onlineddl_test values (null, '13');
+  insert into onlineddl_test values (null, '17');
+end ;;

go/test/endtoend/onlineddl/vrepl_suite/testdata/utf8mb4-to-int/ignore_versions

@@ -0,0 +1 @@
+(5.5|5.6)

go/vt/vttablet/onlineddl/vrepl.go

@@ -472,7 +472,8 @@ func (v *VRepl) generateFilterQuery(ctx context.Context) error {
 				return vterrors.Errorf(vtrpcpb.Code_INVALID_ARGUMENT, "Character set %s not supported for column %s", sourceCol.Charset, sourceCol.Name)
 			}
 			toEncoding, ok := mysql.CharacterSetEncoding[targetCol.Charset]
-			if !ok {
+			// Let's see if target col is at all textual
+			if targetCol.Type == vrepl.StringColumnType && !ok {
 				return vterrors.Errorf(vtrpcpb.Code_INVALID_ARGUMENT, "Character set %s not supported for column %s", targetCol.Charset, targetCol.Name)
 			}
 			if fromEncoding == nil && toEncoding == nil {