From 5dda4dba6f7a6a0f4708d82731c2abb2f6311ee4 Mon Sep 17 00:00:00 2001
From: sima <simondominic9997@outlook.com>
Date: Wed, 26 Jun 2024 09:43:49 +0800
Subject: [PATCH] fix:[TD-30730] Change doc's description about functions.

---
 docs/en/12-taos-sql/10-function.md | 6 +++---
 docs/zh/12-taos-sql/10-function.md | 6 +++---
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/docs/en/12-taos-sql/10-function.md b/docs/en/12-taos-sql/10-function.md
index 27dbbfcc08..4bd701f713 100644
--- a/docs/en/12-taos-sql/10-function.md
+++ b/docs/en/12-taos-sql/10-function.md
@@ -398,7 +398,7 @@ Conversion functions change the data type of a value.
 CAST(expr AS type_name)
 ```
 
-**Description**: Convert the input data `expr` into the type specified by `type_name`. This function can be used only in SELECT statements.
+**Description**: Convert the input data `expr` into the type specified by `type_name`.
 
 **Return value type**: The type specified by parameter `type_name`
 
@@ -435,8 +435,7 @@ TO_ISO8601(expr [, timezone])
 **More explanations**:
 
 - You can specify a time zone in the following format: [z/Z, +/-hhmm, +/-hh, +/-hh:mm]. For example, TO_ISO8601(1, "+00:00").
-- If the input is a UNIX timestamp, the precision of the returned value is determined by the digits of the input timestamp
-- If the input is a column of TIMESTAMP type, the precision of the returned value is same as the precision set for the current data base in use
+- The precision of the input timestamp will be recognized automatically according to the precision of the table used, milliseconds will be used if no table is specified.
 
 
 #### TO_JSON
@@ -650,6 +649,7 @@ use_current_timezone: {
 - Time unit specified by `time_unit` can be:
           1b (nanoseconds), 1u (microseconds), 1a (milliseconds), 1s (seconds), 1m (minutes), 1h (hours), 1d (days), or 1w (weeks)
 - The precision of the returned timestamp is same as the precision set for the current data base in use
+- The precision of the input timestamp will be recognized automatically according to the precision of the table used, milliseconds will be used if no table is specified.
 - If the input data is not formatted as a timestamp, the returned value is null.
 - When using 1d/1w as the time unit to truncate timestamp, you can specify whether to truncate based on the current time zone by setting the use_current_timezone parameter.
   Value 0 indicates truncation using the UTC time zone, value 1 indicates truncation using the current time zone.
diff --git a/docs/zh/12-taos-sql/10-function.md b/docs/zh/12-taos-sql/10-function.md
index 6f4f9b3d84..26996a39fd 100644
--- a/docs/zh/12-taos-sql/10-function.md
+++ b/docs/zh/12-taos-sql/10-function.md
@@ -398,7 +398,7 @@ UPPER(expr)
 CAST(expr AS type_name)
 ```
 
-**功能说明**：数据类型转换函数，返回 expr 转换为 type_name 指定的类型后的结果。只适用于 select 子句中。
+**功能说明**：数据类型转换函数，返回 expr 转换为 type_name 指定的类型后的结果。
 
 **返回结果类型**：CAST 中指定的类型（type_name)。
 
@@ -435,8 +435,7 @@ TO_ISO8601(expr [, timezone])
 **使用说明**：
 
 - timezone 参数允许输入的时区格式为: [z/Z, +/-hhmm, +/-hh, +/-hh:mm]。例如，TO_ISO8601(1, "+00:00")。
-- 如果输入是表示 UNIX 时间戳的整形，返回格式精度由时间戳的位数决定;
-- 如果输入是 TIMESTAMP 类型的列，返回格式的时间戳精度与当前 DATABASE 设置的时间精度一致。
+- 输入时间戳的精度由所查询表的精度确定, 若未指定表, 则精度为毫秒.
 
 
 #### TO_JSON
@@ -650,6 +649,7 @@ use_current_timezone: {
 - 支持的时间单位 time_unit 如下：
           1b(纳秒), 1u(微秒)，1a(毫秒)，1s(秒)，1m(分)，1h(小时)，1d(天), 1w(周)。
 - 返回的时间戳精度与当前 DATABASE 设置的时间精度一致。
+- 输入时间戳的精度由所查询表的精度确定, 若未指定表, 则精度为毫秒.
 - 输入包含不符合时间日期格式的字符串则返回 NULL。
 - 当使用 1d/1w 作为时间单位对时间戳进行截断时， 可通过设置 use_current_timezone 参数指定是否根据当前时区进行截断处理。
   值 0 表示使用 UTC 时区进行截断，值 1 表示使用当前时区进行截断。