将amount值转换成字符串，长度为转换后的实际长度，配置的长度无效。

insert into temp select cast(amount as VARCHAR(10)) from source_stream;

常用类型转换函数

/** source **/
CREATE
SOURCE STREAM car_infos (cast_int_to_varchar int, cast_String_to_int string,
case_string_to_timestamp string, case_timestamp_to_date timestamp) WITH (
  type = "dis",
  region = "xxxxx",
  channel = "dis-input",
  partition_count = "1",
  encode = "json",
  offset = "13",
  json_config =
"cast_int_to_varchar=cast_int_to_varchar;cast_String_to_int=cast_String_to_int;case_string_to_timestamp=case_string_to_timestamp;case_timestamp_to_date=case_timestamp_to_date"
/** sink **/
CREATE
SINK STREAM cars_infos_out (cast_int_to_varchar varchar, cast_String_to_int
int, case_string_to_timestamp timestamp, case_timestamp_to_date date) WITH (
  type = "dis",
  region = "xxxxx",
  channel = "dis-output",
  partition_count = "1",
  encode = "json",
  offset = "4",
  json_config =
"cast_int_to_varchar=cast_int_to_varchar;cast_String_to_int=cast_String_to_int;case_string_to_timestamp=case_string_to_timestamp;case_timestamp_to_date=case_timestamp_to_date",
  enable_output_null="true"
/** 统计car的静态信息 **/
INSERT
  cars_infos_out
SELECT
  cast(cast_int_to_varchar as varchar),
  cast(cast_String_to_int as int),
  cast(case_string_to_timestamp as timestamp),
  cast(case_timestamp_to_date as date)
  car_infos;