Add SUBSTRING

Author: seesharprun

articles/cosmos-db/nosql/query/substring.md

@@ -1,59 +1,56 @@
 ---
-title: SUBSTRING in Azure Cosmos DB query language
-description: Learn about SQL system function SUBSTRING in Azure Cosmos DB.
-author: ginamr
+title: SUBSTRING
+titleSuffix: Azure Cosmos DB for NoSQL
+description: An Azure Cosmos DB for NoSQL system function that returns a portion of a string using a starting position and length.
+author: jcodella
+ms.author: jacodel
+ms.reviewer: sidandrews
 ms.service: cosmos-db
 ms.subservice: nosql
-ms.topic: conceptual
-ms.date: 09/13/2019
-ms.author: girobins
-ms.custom: query-reference, ignite-2022
+ms.topic: reference
+ms.date: 07/24/2023
+ms.custom: query-reference
 ---
-# SUBSTRING (Azure Cosmos DB)
+
+# SUBSTRING (NoSQL query)
+
 [!INCLUDE[NoSQL](../../includes/appliesto-nosql.md)]
 
- Returns part of a string expression starting at the specified character zero-based position and continues to the specified length, or to the end of the string.  
-  
+Returns part of a string expression starting at the specified position and of the specified length, or to the end of the string.  
+
 ## Syntax
-  
+
 ```sql
-SUBSTRING(<str_expr>, <num_expr1>, <num_expr2>)  
-```  
-  
+SUBSTRING(<string_expr>, <numeric_expr_1>, <numeric_expr_2>)  
+```
+
 ## Arguments
-  
-*str_expr*  
-   Is a string expression.
-  
-*num_expr1*  
-   Is a numeric expression to denote the start character. A value of 0 is the first character of *str_expr*.
-  
-*num_expr2*  
-   Is a numeric expression to denote the maximum number of characters of *str_expr* to be returned. A value of 0 or less results in empty string.
+
+| | Description |
+| --- | --- |
+| **`string_expr`** | A string expression. |
+| **`numeric_expr_1`** | A numeric expression to denote the start character.  |
+| **`numeric_expr_2`** | A numeric expression to denote the maximum number of characters of `string_expr` to be returned.  |
 
 ## Return types
-  
-  Returns a string expression.  
-  
+
+Returns a string expression.  
+
 ## Examples
-  
-  The following example returns the substring of "abc" starting at 1 and for a length of 1 character.  
-  
-```sql
-SELECT SUBSTRING("abc", 1, 1) AS substring  
-```  
-  
- Here is the result set.  
-  
-```json
-[{"substring": "b"}]  
-```
+
+The following example returns substrings with various lengths and starting positions.
+
+:::code language="sql" source="~/cosmos-db-nosql-query-samples/scripts/substring/query.sql" highlight="2-5":::
+
+:::code language="json" source="~/cosmos-db-nosql-query-samples/scripts/substring/result.json":::
 
 ## Remarks
 
-This system function will benefit from a [range index](../../index-policy.md#includeexclude-strategy) if the starting position is `0`.
+- This function benefits from a [range index](../../index-policy.md#includeexclude-strategy) if the starting position is `0`.
+- `numeric_expr_1` positions are zero-based, therefore a value of `0` starts from the first character of `string_expr`.
+- A value of `0` or less for `numeric_expr_2` results in empty string.
 
 ## Next steps
 
 - [System functions Azure Cosmos DB](system-functions.yml)
-- [Introduction to Azure Cosmos DB](../../introduction.md)
+- [`StringEquals`](stringequals.md)