Fix 9347 panic case statements info schema

enginetest/queries/information_schema_queries.go

@@ -30,6 +30,17 @@ var InfoSchemaQueries = []QueryTest{
 		Query:    "SHOW KEYS FROM `columns` FROM `information_schema`;",
 		Expected: []sql.Row{},
 	},
+	{
+		Query: `SELECT table_schema AS TABLE_CAT,
+       			NULL AS TABLE_SCHEM,
+       			table_name,
+       			CASE WHEN table_type = 'BASE TABLE' THEN
+       			    CASE WHEN table_schema = 'mysql' OR table_schema = 'performance_schema' THEN 'SYSTEM TABLE'
+       			 	ELSE 'TABLE' END
+       			WHEN table_type = 'TEMPORARY' THEN 'LOCAL_TEMPORARY'
+       			ELSE table_type END AS TABLE_TYPE FROM information_schema.tables ORDER BY table_name LIMIT 1;`,
+		Expected: []sql.Row{{"information_schema", nil, "administrable_role_authorizations", "SYSTEM VIEW"}},
+	},
 	{
 		Query: `SELECT 
      table_name, index_name, comment, non_unique, GROUP_CONCAT(column_name ORDER BY seq_in_index) AS COLUMNS 

sql/expression/enum.go

@@ -69,7 +69,15 @@ func (e *EnumToString) Eval(ctx *sql.Context, row sql.Row) (interface{}, error)
 	}
 
 	enumType := e.Enum.Type().(types.EnumType)
-	str, _ := enumType.At(int(val.(uint16)))
+	var str string
+	switch v := val.(type) {
+	case uint16:
+		str, _ = enumType.At(int(v))
+	case string:
+		str = v
+	default:
+		return nil, sql.ErrInvalidType.New(val, types.Text)
+	}
 	return str, nil
 }
 

sql/information_schema/tables_table.go

@@ -65,7 +65,7 @@ var tablesSchema = Schema{
 func tablesRowIter(ctx *Context, cat Catalog) (RowIter, error) {
 	var rows []Row
 	var (
-		tableType      string
+		tableType      uint16
 		tableRows      uint64
 		avgRowLength   uint64
 		dataLength     uint64
@@ -82,9 +82,9 @@ func tablesRowIter(ctx *Context, cat Catalog) (RowIter, error) {
 
 	for _, db := range databases {
 		if db.Database.Name() == InformationSchemaDatabaseName {
-			tableType = "SYSTEM VIEW"
+			tableType = 3 // SYSTEM_VIEW
 		} else {
-			tableType = "BASE TABLE"
+			tableType = 1 // BASE_TABLE
 			engine = "InnoDB"
 			rowFormat = "Dynamic"
 		}