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Update 10-function.md

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docs/en/12-taos-sql/10-function.md
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@ -565,7 +565,7 @@ TO_TIMESTAMP(ts_str_literal, format_str_literal)
- The uppercase or lowercase of `MONTH`, `MON`, `DAY`, `DY` and formtas that output digits have same effect when used in `to_timestamp`, like `to_timestamp('2023-JANUARY-01', 'YYYY-month-dd')`, `month` can be replaced by `MONTH`, or `month`. The cases are ignored.
- If multi times are specified for one component, the previous will be overwritten. Like `to_timestamp('2023-22-10-10', 'yyyy-yy-MM-dd')`, the output year will be `2022`.
- To avoid unexpected time zone used during the convertion, it's recommended to put time zone in the ts string, e.g. '2023-10-10 10:10:10+08'. If time zone not specified, default will be that in server or client.
- The default timestamp if some components are not specified will be: `1970-01-01 00:00:00` with the timezone specified or default to local timezone. If `DDD` is specified without `DD`, server will report `not supported` error, e.g. format 'yyyy-mm-ddd' is not supported currently, specify month day instead.
- The default timestamp if some components are not specified will be: `1970-01-01 00:00:00` with the timezone specified or default to local timezone. Only `DDD` is specified without `DD` is not supported currently, e.g. format 'yyyy-mm-ddd' is not supported, but 'yyyy-mm-dd' is supported.
- If `AM` or `PM` is specified in formats, the Hour must between `1-12`.
- In some cases, `to_timestamp` can convert correctly even the format and the timestamp string are not totally matched. Like `to_timetamp('200101/2', 'yyyyMM1/dd')`, the digit `1` in format string are ignored, and the output timestsamp is `2001-01-02 00:00:00`. Spaces and tabs in formats and tiemstamp string are also ignored automatically.
- The precision of the output timestamp will be the same as the table in SELECT stmt, millisecond will be used if no table is specified. The output of `select to_timestamp('2023-08-1 10:10:10.123456789', 'yyyy-mm-dd hh:mi:ss.ns')` will be truncated to millisecond precision. If a nano precision table is specified, no truncation will be applied. Like `select to_timestamp('2023-08-1 10:10:10.123456789', 'yyyy-mm-dd hh:mi:ss.ns') from db_ns.table_ns limit 1`.