[18.x] Fix schemacopy collation issues (#15859)

go/mysql/schema.go

@@ -39,13 +39,13 @@ const (
 	DetectSchemaChange = `
 SELECT DISTINCT table_name
 FROM (
-	SELECT table_name, column_name, ordinal_position, character_set_name, collation_name, data_type, column_key
+	SELECT table_name COLLATE utf8mb3_bin AS table_name, column_name COLLATE utf8mb3_general_ci AS column_name, ordinal_position, character_set_name COLLATE utf8mb3_general_ci AS character_set_name, collation_name COLLATE utf8mb3_general_ci AS collation_name, data_type COLLATE utf8mb3_bin AS data_type, column_key COLLATE utf8mb3_bin AS column_key
 	FROM information_schema.columns
 	WHERE table_schema = database()
 
 	UNION ALL
 
-	SELECT table_name, column_name, ordinal_position, character_set_name, collation_name, data_type, column_key
+	SELECT table_name COLLATE utf8mb3_bin AS table_name, column_name COLLATE utf8mb3_general_ci AS column_name, ordinal_position, character_set_name COLLATE utf8mb3_general_ci AS character_set_name, collation_name COLLATE utf8mb3_general_ci AS collation_name, data_type COLLATE utf8mb3_bin AS data_type, column_key COLLATE utf8mb3_bin AS column_key
 	FROM %s.schemacopy
 	WHERE table_schema = database()
 ) _inner

go/vt/sidecardb/schema/schematracker/schemacopy.sql

@@ -16,13 +16,13 @@ limitations under the License.
 
 CREATE TABLE IF NOT EXISTS schemacopy
 (
-    `table_schema`       varchar(64)     NOT NULL,
-    `table_name`         varchar(64)     NOT NULL,
-    `column_name`        varchar(64)     NOT NULL,
-    `ordinal_position`   bigint unsigned NOT NULL,
-    `character_set_name` varchar(32) DEFAULT NULL,
-    `collation_name`     varchar(32) DEFAULT NULL,
-    `data_type`          varchar(64)     NOT NULL,
-    `column_key`         varchar(3)      NOT NULL,
+    `table_schema`          varchar(64) CHARACTER SET utf8mb3 COLLATE utf8mb3_bin         NOT NULL,
+    `table_name`            varchar(64) CHARACTER SET utf8mb3 COLLATE utf8mb3_bin         NOT NULL,
+    `column_name`           varchar(64) CHARACTER SET utf8mb3 COLLATE utf8mb3_general_ci  NOT NULL,
+    `ordinal_position`      bigint unsigned                                               NOT NULL,
+    `character_set_name`    varchar(32) CHARACTER SET utf8mb3 COLLATE utf8mb3_general_ci  DEFAULT NULL,
+    `collation_name`        varchar(32) CHARACTER SET utf8mb3 COLLATE utf8mb3_general_ci  DEFAULT NULL,
+    `data_type`             varchar(64) CHARACTER SET utf8mb3 COLLATE utf8mb3_bin         NOT NULL,
+    `column_key`            varchar(3)  CHARACTER SET utf8mb3 COLLATE utf8mb3_bin         NOT NULL,
     PRIMARY KEY (`table_schema`, `table_name`, `ordinal_position`)
-) ENGINE = InnoDB
+) ENGINE = InnoDB, CHARACTER SET = utf8mb3