gengliangwang commented on code in PR #36950:
URL: https://github.com/apache/spark/pull/36950#discussion_r903082475
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docs/sql-ref-number-pattern.md:
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@@ -19,4 +19,101 @@ license: |
limitations under the License.
---
-TODO: Add the content of Number Patterns for Formatting and Parsing
+### Description
+
+Functions such as `to_number` and `try_to_number` support converting between
values of string and
+Decimal type. Such functions accept format strings indicating how to map
between these types.
+
+### Syntax
+
+Number format strings support the following syntax:
+```
+ { ' [ S ] [ L | $ ]
+ [ 0 | 9 | G | , ] [...]
+ [ . | D ]
+ [ 0 | 9 ] [...]
+ [ L | $ ] [ PR | MI | S ] ' }
+```
+
+### Elements
+
+Each number format string can contain the following elements (case
insensitive):
+
+- **`0`** or **`9`**
+
+ Specifies an expected digit between `0` and `9`.
+
+ A `0` to the left of the decimal point indicates that at least this many
digits must be present.
+
+ A leading `9` indicates that these digits are optional.
+
+ The input value must not be larger than the number of digits to the left of
the decimal point
+ allowed by the format string.
+
+ Digits to the right of the decimal point in the format string indicate the
most digits that the
+ input value may have to the right of the decimal point.
+
+- **`.`** or **`D`**
+
+ Specifies the position of the decimal point.
+
+ The input value does not need to include a decimal point.
+
+- **`,`** or **`G`**
+
+ Specifies the position of the `,` grouping (thousands) separator.
+
+ There must be a `0` or `9` to the left and right of each grouping separator.
+
+- **`$`**
+
+ Specifies the location of the `$` currency sign. This character may only be
specified once.
+
+- **`S`**
+
+ Specifies the position of an optional '+' or '-' sign. This character may
only be specified once.
+
+- **`MI`**
+
+ Specifies an optional `-` sign at the end, but no `+`.
+
+- **`PR`**
+
+ Maps negative input values to wrapping angle brackets (`<1>`) in the
corresponding string.
+
+ Positive input values do not receive wrapping angle brackets.
+
+### Examples
+
+The following examples use the `try_to_number` SQL function which accepts an
input string as the
Review Comment:
It would be great if we can have examples for to_number as well
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