Merge pull request #188033 from Clare-Zheng82/0208-Add_CTE_use_method_to_SQL_connector_docs

Add a Tip about CTE in SQL connector docs

Author: PRMerger15

articles/data-factory/connector-azure-sql-database.md

@@ -8,7 +8,7 @@ ms.service: data-factory
 ms.subservice: data-movement
 ms.topic: conceptual
 ms.custom: synapse
-ms.date: 01/28/2022
+ms.date: 02/08/2022
 ---
 
 # Copy and transform data in Azure SQL Database by using Azure Data Factory or Azure Synapse Analytics
@@ -756,6 +756,18 @@ Settings specific to Azure SQL Database are available in the **Source Options**
 
 **Query**: If you select Query in the input field, enter a SQL query for your source. This setting overrides any table that you've chosen in the dataset. **Order By** clauses aren't supported here, but you can set a full SELECT FROM statement. You can also use user-defined table functions. **select * from udfGetData()** is a UDF in SQL that returns a table. This query will produce a source table that you can use in your data flow. Using queries is also a great way to reduce rows for testing or for lookups.
 
+> [!TIP]
+> The [common table expression (CTE)](/sql/t-sql/queries/with-common-table-expression-transact-sql?view=sql-server-ver15&preserve-view=true) in SQL is not supported in the mapping data flow **Query** mode, because the prerequisite of using this mode is that queries can be used in the SQL query FROM clause but CTEs cannot do this.
+>To use CTEs, you need to create a stored procedure using the following query:
+>```SQL
+> CREATE PROC CTESP @query nvarchar(max)
+> AS
+> BEGIN
+> EXECUTE sp_executesql @query;
+> END
+>```
+>Then use the **Stored procedure** mode in the source transformation of the mapping data flow and set the `@query` like example `with CTE as (select 'test' as a) select * from CTE`. Then you can use CTEs as expected.
+
 **Stored procedure**: Choose this option if you wish to generate a projection and source data from a stored procedure that is executed from your source database. You can type in the schema, procedure name, and parameters, or click on Refresh to ask the service to discover the schemas and procedure names. Then you can click on Import to import all procedure parameters using the form ``@paraName``.
 
 :::image type="content" source="media/data-flow/stored-procedure-2.png" alt-text="Stored procedure":::

articles/data-factory/connector-azure-sql-managed-instance.md

@@ -8,7 +8,7 @@ ms.topic: conceptual
 ms.author: jianleishen
 author: jianleishen
 ms.custom: synapse
-ms.date: 01/28/2022
+ms.date: 02/08/2022
 ---
 
 # Copy and transform data in Azure SQL Managed Instance using Azure Data Factory or Synapse Analytics
@@ -765,6 +765,18 @@ The below table lists the properties supported by Azure SQL Managed Instance sou
 | Batch size | Specify a batch size to chunk large data into reads. | No | Integer | batchSize |
 | Isolation Level | Choose one of the following isolation levels:<br>- Read Committed<br>- Read Uncommitted (default)<br>- Repeatable Read<br>- Serializable<br>- None (ignore isolation level) | No | <small>READ_COMMITTED<br/>READ_UNCOMMITTED<br/>REPEATABLE_READ<br/>SERIALIZABLE<br/>NONE</small> |isolationLevel |
 
+> [!TIP]
+> The [common table expression (CTE)](/sql/t-sql/queries/with-common-table-expression-transact-sql?view=sql-server-ver15&preserve-view=true) in SQL is not supported in the mapping data flow **Query** mode, because the prerequisite of using this mode is that queries can be used in the SQL query FROM clause but CTEs cannot do this.
+>To use CTEs, you need to create a stored procedure using the following query:
+>```SQL
+> CREATE PROC CTESP @query nvarchar(max)
+> AS
+> BEGIN
+> EXECUTE sp_executesql @query;
+> END
+>```
+>Then use the **Stored procedure** mode in the source transformation of the mapping data flow and set the `@query` like example `with CTE as (select 'test' as a) select * from CTE`. Then you can use CTEs as expected.
+
 #### Azure SQL Managed Instance source script example
 
 When you use Azure SQL Managed Instance as source type, the associated data flow script is:

articles/data-factory/connector-sql-server.md

@@ -8,7 +8,7 @@ ms.service: data-factory
 ms.subservice: data-movement
 ms.topic: conceptual
 ms.custom: synapse
-ms.date: 01/28/2022
+ms.date: 02/08/2022
 ---
 
 # Copy and transform data to and from SQL Server by using Azure Data Factory or Azure Synapse Analytics
@@ -640,6 +640,18 @@ The below table lists the properties supported by SQL Server source. You can edi
 | Batch size | Specify a batch size to chunk large data into reads. | No | Integer | batchSize |
 | Isolation Level | Choose one of the following isolation levels:<br>- Read Committed<br>- Read Uncommitted (default)<br>- Repeatable Read<br>- Serializable<br>- None (ignore isolation level) | No | <small>READ_COMMITTED<br/>READ_UNCOMMITTED<br/>REPEATABLE_READ<br/>SERIALIZABLE<br/>NONE</small> |isolationLevel |
 
+> [!TIP]
+> The [common table expression (CTE)](/sql/t-sql/queries/with-common-table-expression-transact-sql?view=sql-server-ver15&preserve-view=true) in SQL is not supported in the mapping data flow **Query** mode, because the prerequisite of using this mode is that queries can be used in the SQL query FROM clause but CTEs cannot do this.
+>To use CTEs, you need to create a stored procedure using the following query:
+>```SQL
+> CREATE PROC CTESP @query nvarchar(max)
+> AS
+> BEGIN
+> EXECUTE sp_executesql @query;
+> END
+>```
+>Then use the **Stored procedure** mode in the source transformation of the mapping data flow and set the `@query` like example `with CTE as (select 'test' as a) select * from CTE`. Then you can use CTEs as expected.
+
 #### SQL Server source script example
 
 When you use SQL Server as source type, the associated data flow script is: