Copy data to and from SQL Server by using Azure Data Factory

This article outlines how to use the copy activity in Azure Data Factory to copy data from and to a SQL Server database. It builds on the copy activity overview article that presents a general overview of the copy activity.

Supported capabilities

This SQL Server connector is supported for the following activities:

You can copy data from a SQL Server database to any supported sink data store. Or, you can copy data from any supported source data store to a SQL Server database. For a list of data stores that are supported as sources or sinks by the copy activity, see the Supported data stores table.

Specifically, this SQL Server connector supports:

  • SQL Server versions 2016, 2014, 2012, 2008 R2, 2008, and 2005.
  • Copying data by using SQL or Windows authentication.
  • As a source, retrieving data by using a SQL query or a stored procedure.
  • As a sink, appending data to a destination table or invoking a stored procedure with custom logic during copy.

SQL Server Express LocalDB is not supported.

Note

SQL Server Always Encrypted isn't supported by this connector now. To work around, you can use a generic ODBC connector and a SQL Server ODBC driver. Follow this guidance with ODBC driver download and connection string configurations.

Prerequisites

If your data store is configured in one of the following ways, you need to set up a Self-hosted Integration Runtime in order to connect to this data store:

  • The data store is located inside an on-premises network, inside Azure Virtual Network, or inside Amazon Virtual Private Cloud.
  • The data store is a managed cloud data service where the access is restricted to IPs whitelisted in the firewall rules.

Get started

You can use one of the following tools or SDKs to use the copy activity with a pipeline. Select a link for step-by-step instructions:

The following sections provide details about properties that are used to define Data Factory entities specific to the SQL Server database connector.

Linked service properties

The following properties are supported for the SQL Server linked service:

Property Description Required
type The type property must be set to SqlServer. Yes
connectionString Specify connectionString information that's needed to connect to the SQL Server database by using either SQL authentication or Windows authentication. Refer to the following samples.
Mark this field as SecureString to store it securely in Azure Data Factory. You also can put a password in Azure Key Vault. If it's SQL authentication, pull the password configuration out of the connection string. For more information, see the JSON example following the table and Store credentials in Azure Key Vault.
Yes
userName Specify a user name if you use Windows authentication. An example is domainname\username. No
password Specify a password for the user account you specified for the user name. Mark this field as SecureString to store it securely in Azure Data Factory. Or, you can reference a secret stored in Azure Key Vault. No
connectVia This integration runtime is used to connect to the data store. Learn more from Prerequisites section. If not specified, the default Azure integration runtime is used. No

Tip

If you hit an error with the error code "UserErrorFailedToConnectToSqlServer" and a message like "The session limit for the database is XXX and has been reached," add Pooling=false to your connection string and try again.

Example 1: Use SQL authentication

{
    "name": "SqlServerLinkedService",
    "properties": {
        "type": "SqlServer",
        "typeProperties": {
            "connectionString": {
                "type": "SecureString",
                "value": "Data Source=<servername>\\<instance name if using named instance>;Initial Catalog=<databasename>;Integrated Security=False;User ID=<username>;Password=<password>;"
            }
        },
        "connectVia": {
            "referenceName": "<name of Integration Runtime>",
            "type": "IntegrationRuntimeReference"
        }
    }
}

Example 2: Use SQL authentication with a password in Azure Key Vault

{
    "name": "SqlServerLinkedService",
    "properties": {
        "type": "SqlServer",
        "typeProperties": {
            "connectionString": {
                "type": "SecureString",
                "value": "Data Source=<servername>\\<instance name if using named instance>;Initial Catalog=<databasename>;Integrated Security=False;User ID=<username>;"
            },
            "password": { 
                "type": "AzureKeyVaultSecret", 
                "store": { 
                    "referenceName": "<Azure Key Vault linked service name>", 
                    "type": "LinkedServiceReference" 
                }, 
                "secretName": "<secretName>" 
            }
        },
        "connectVia": {
            "referenceName": "<name of Integration Runtime>",
            "type": "IntegrationRuntimeReference"
        }
    }
}

Example 3: Use Windows authentication

{
    "name": "SqlServerLinkedService",
    "properties": {
        "type": "SqlServer",
        "typeProperties": {
            "connectionString": {
                "type": "SecureString",
                "value": "Data Source=<servername>\\<instance name if using named instance>;Initial Catalog=<databasename>;Integrated Security=True;"
            },
            "userName": "<domain\\username>",
            "password": {
                "type": "SecureString",
                "value": "<password>"
            }
        },
        "connectVia": {
            "referenceName": "<name of Integration Runtime>",
            "type": "IntegrationRuntimeReference"
        }
     }
}

Dataset properties

For a full list of sections and properties available for defining datasets, see the datasets article. This section provides a list of properties supported by the SQL Server dataset.

To copy data from and to a SQL Server database, the following properties are supported:

Property Description Required
type The type property of the dataset must be set to SqlServerTable. Yes
schema Name of the schema. No for source, Yes for sink
table Name of the table/view. No for source, Yes for sink
tableName Name of the table/view with schema. This property is supported for backward compatibility. For new workload, use schema and table. No for source, Yes for sink

Example

{
    "name": "SQLServerDataset",
    "properties":
    {
        "type": "SqlServerTable",
        "linkedServiceName": {
            "referenceName": "<SQL Server linked service name>",
            "type": "LinkedServiceReference"
        },
        "schema": [ < physical schema, optional, retrievable during authoring > ],
        "typeProperties": {
            "schema": "<schema_name>",
            "table": "<table_name>"
        }
    }
}

Copy activity properties

For a full list of sections and properties available for use to define activities, see the Pipelines article. This section provides a list of properties supported by the SQL Server source and sink.

SQL Server as a source

To copy data from SQL Server, set the source type in the copy activity to SqlSource. The following properties are supported in the copy activity source section:

Property Description Required
type The type property of the copy activity source must be set to SqlSource. Yes
sqlReaderQuery Use the custom SQL query to read data. An example is select * from MyTable. No
sqlReaderStoredProcedureName This property is the name of the stored procedure that reads data from the source table. The last SQL statement must be a SELECT statement in the stored procedure. No
storedProcedureParameters These parameters are for the stored procedure.
Allowed values are name or value pairs. The names and casing of parameters must match the names and casing of the stored procedure parameters.
No

Points to note:

  • If sqlReaderQuery is specified for SqlSource, the copy activity runs this query against the SQL Server source to get the data. You also can specify a stored procedure by specifying sqlReaderStoredProcedureName and storedProcedureParameters if the stored procedure takes parameters.
  • If you don't specify either sqlReaderQuery or sqlReaderStoredProcedureName, the columns defined in the "structure" section of the dataset JSON are used to construct a query. The query select column1, column2 from mytable runs against the SQL Server. If the dataset definition doesn't have "structure," all columns are selected from the table.

Example: Use SQL query

"activities":[
    {
        "name": "CopyFromSQLServer",
        "type": "Copy",
        "inputs": [
            {
                "referenceName": "<SQL Server input dataset name>",
                "type": "DatasetReference"
            }
        ],
        "outputs": [
            {
                "referenceName": "<output dataset name>",
                "type": "DatasetReference"
            }
        ],
        "typeProperties": {
            "source": {
                "type": "SqlSource",
                "sqlReaderQuery": "SELECT * FROM MyTable"
            },
            "sink": {
                "type": "<sink type>"
            }
        }
    }
]

Example: Use a stored procedure

"activities":[
    {
        "name": "CopyFromSQLServer",
        "type": "Copy",
        "inputs": [
            {
                "referenceName": "<SQL Server input dataset name>",
                "type": "DatasetReference"
            }
        ],
        "outputs": [
            {
                "referenceName": "<output dataset name>",
                "type": "DatasetReference"
            }
        ],
        "typeProperties": {
            "source": {
                "type": "SqlSource",
                "sqlReaderStoredProcedureName": "CopyTestSrcStoredProcedureWithParameters",
                "storedProcedureParameters": {
                    "stringData": { "value": "str3" },
                    "identifier": { "value": "$$Text.Format('{0:yyyy}', <datetime parameter>)", "type": "Int"}
                }
            },
            "sink": {
                "type": "<sink type>"
            }
        }
    }
]

The stored procedure definition

CREATE PROCEDURE CopyTestSrcStoredProcedureWithParameters
(
    @stringData varchar(20),
    @identifier int
)
AS
SET NOCOUNT ON;
BEGIN
    select *
    from dbo.UnitTestSrcTable
    where dbo.UnitTestSrcTable.stringData != stringData
    and dbo.UnitTestSrcTable.identifier != identifier
END
GO

SQL Server as a sink

Tip

Learn more about the supported write behaviors, configurations, and best practices from Best practice for loading data into SQL Server.

To copy data to SQL Server, set the sink type in the copy activity to SqlSink. The following properties are supported in the copy activity sink section:

Property Description Required
type The type property of the copy activity sink must be set to SqlSink. Yes
writeBatchSize Number of rows to insert into the SQL table per batch.
Allowed values are integers for the number of rows. By default, Azure Data Factory dynamically determines the appropriate batch size based on the row size.
No
writeBatchTimeout This property specifies the wait time for the batch insert operation to complete before it times out.
Allowed values are for the timespan. An example is “00:30:00” for 30 minutes. If no value is specified, the timeout defaults to "02:00:00".
No
preCopyScript This property specifies a SQL query for the copy activity to run before writing data into SQL Server. It's invoked only once per copy run. You can use this property to clean up the preloaded data. No
sqlWriterStoredProcedureName The name of the stored procedure that defines how to apply source data into a target table.
This stored procedure is invoked per batch. For operations that run only once and have nothing to do with source data, for example, delete or truncate, use the preCopyScript property.
No
storedProcedureTableTypeParameterName The parameter name of the table type specified in the stored procedure. No
sqlWriterTableType The table type name to be used in the stored procedure. The copy activity makes the data being moved available in a temp table with this table type. Stored procedure code can then merge the data that's being copied with existing data. No
storedProcedureParameters Parameters for the stored procedure.
Allowed values are name and value pairs. Names and casing of parameters must match the names and casing of the stored procedure parameters.
No
tableOption Specifies whether to automatically create the sink table if not exists based on the source schema. Auto table creation is not supported when sink specifies stored procedure or staged copy is configured in copy activity. Allowed values are: none (default), autoCreate. No

Example 1: Append data

"activities":[
    {
        "name": "CopyToSQLServer",
        "type": "Copy",
        "inputs": [
            {
                "referenceName": "<input dataset name>",
                "type": "DatasetReference"
            }
        ],
        "outputs": [
            {
                "referenceName": "<SQL Server output dataset name>",
                "type": "DatasetReference"
            }
        ],
        "typeProperties": {
            "source": {
                "type": "<source type>"
            },
            "sink": {
                "type": "SqlSink",
                "writeBatchSize": 100000,
                "tableOption": "autoCreate"
            }
        }
    }
]

Example 2: Invoke a stored procedure during copy

Learn more details from Invoke a stored procedure from a SQL sink.

"activities":[
    {
        "name": "CopyToSQLServer",
        "type": "Copy",
        "inputs": [
            {
                "referenceName": "<input dataset name>",
                "type": "DatasetReference"
            }
        ],
        "outputs": [
            {
                "referenceName": "<SQL Server output dataset name>",
                "type": "DatasetReference"
            }
        ],
        "typeProperties": {
            "source": {
                "type": "<source type>"
            },
            "sink": {
                "type": "SqlSink",
                "sqlWriterStoredProcedureName": "CopyTestStoredProcedureWithParameters",
                "storedProcedureTableTypeParameterName": "MyTable",
                "sqlWriterTableType": "MyTableType",
                "storedProcedureParameters": {
                    "identifier": { "value": "1", "type": "Int" },
                    "stringData": { "value": "str1" }
                }
            }
        }
    }
]

Best practice for loading data into SQL Server

When you copy data into SQL Server, you might require different write behavior:

  • Append: My source data has only new records.
  • Upsert: My source data has both inserts and updates.
  • Overwrite: I want to reload the entire dimension table each time.
  • Write with custom logic: I need extra processing before the final insertion into the destination table.

See the respective sections for how to configure in Azure Data Factory and best practices.

Append data

Appending data is the default behavior of this SQL Server sink connector. Azure Data Factory does a bulk insert to write to your table efficiently. You can configure the source and sink accordingly in the copy activity.

Upsert data

Option 1: When you have a large amount of data to copy, use the following approach to do an upsert:

  • First, use a temporary table to bulk load all records by using the copy activity. Because operations against temporary tables aren't logged, you can load millions of records in seconds.
  • Run a stored procedure activity in Azure Data Factory to apply a MERGE or INSERT/UPDATE statement. Use the temp table as a source to perform all updates or inserts as a single transaction. In this way, the number of round trips and log operations is reduced. At the end of the stored procedure activity, the temp table can be truncated to be ready for the next upsert cycle.

As an example, in Azure Data Factory, you can create a pipeline with a Copy activity chained with a Stored Procedure activity. The former copies data from your source store into a database temporary table, for example, ##UpsertTempTable, as the table name in the dataset. Then the latter invokes a stored procedure to merge source data from the temp table into the target table and clean up the temp table.

Upsert

In your database, define a stored procedure with MERGE logic, like the following example, which is pointed to from the previous stored procedure activity. Assume that the target is the Marketing table with three columns: ProfileID, State, and Category. Do the upsert based on the ProfileID column.

CREATE PROCEDURE [dbo].[spMergeData]
AS
BEGIN
	MERGE TargetTable AS target
	USING ##UpsertTempTable AS source
	ON (target.[ProfileID] = source.[ProfileID])
	WHEN MATCHED THEN
		UPDATE SET State = source.State
    WHEN NOT matched THEN
    	INSERT ([ProfileID], [State], [Category])
      VALUES (source.ProfileID, source.State, source.Category);
    
    TRUNCATE TABLE ##UpsertTempTable
END

Option 2: You also can choose to invoke a stored procedure within the copy activity. This approach runs each row in the source table instead of using bulk insert as the default approach in the copy activity, which isn't appropriate for large-scale upsert.

Overwrite the entire table

You can configure the preCopyScript property in a copy activity sink. In this case, for each copy activity that runs, Azure Data Factory runs the script first. Then it runs the copy to insert the data. For example, to overwrite the entire table with the latest data, specify a script to first delete all the records before you bulk load the new data from the source.

Write data with custom logic

The steps to write data with custom logic are similar to those described in the Upsert data section. When you need to apply extra processing before the final insertion of source data into the destination table, for large scale, you can do one of two things:

  • Load to a temporary table and then invoke a stored procedure.
  • Invoke a stored procedure during copy.

Invoke a stored procedure from a SQL sink

When you copy data into a SQL Server database, you also can configure and invoke a user-specified stored procedure with additional parameters. The stored procedure feature takes advantage of table-valued parameters.

Tip

Invoking a stored procedure processes the data row by row instead of by using a bulk operation, which we don't recommend for large-scale copy. Learn more from Best practice for loading data into SQL Server.

You can use a stored procedure when built-in copy mechanisms don't serve the purpose. An example is when you want to apply extra processing before the final insertion of source data into the destination table. Some extra processing examples are when you want to merge columns, look up additional values, and insert data into more than one table.

The following sample shows how to use a stored procedure to do an upsert into a table in the SQL Server database. Assume that the input data and the sink Marketing table each have three columns: ProfileID, State, and Category. Do the upsert based on the ProfileID column, and only apply it for a specific category called "ProductA".

  1. In your database, define the table type with the same name as sqlWriterTableType. The schema of the table type is the same as the schema returned by your input data.

    CREATE TYPE [dbo].[MarketingType] AS TABLE(
        [ProfileID] [varchar](256) NOT NULL,
        [State] [varchar](256) NOT NULL,
        [Category] [varchar](256) NOT NULL
    )
    
  2. In your database, define the stored procedure with the same name as sqlWriterStoredProcedureName. It handles input data from your specified source and merges into the output table. The parameter name of the table type in the stored procedure is the same as tableName defined in the dataset.

    CREATE PROCEDURE spOverwriteMarketing @Marketing [dbo].[MarketingType] READONLY, @category varchar(256)
    AS
    BEGIN
    MERGE [dbo].[Marketing] AS target
    USING @Marketing AS source
    ON (target.ProfileID = source.ProfileID and target.Category = @category)
    WHEN MATCHED THEN
        UPDATE SET State = source.State
    WHEN NOT MATCHED THEN
        INSERT (ProfileID, State, Category)
        VALUES (source.ProfileID, source.State, source.Category);
    END
    
  3. In Azure Data Factory, define the SQL sink section in the copy activity as follows:

    "sink": {
        "type": "SqlSink",
        "sqlWriterStoredProcedureName": "spOverwriteMarketing",
        "storedProcedureTableTypeParameterName": "Marketing",
        "sqlWriterTableType": "MarketingType",
        "storedProcedureParameters": {
            "category": {
                "value": "ProductA"
            }
        }
    }
    

Data type mapping for SQL Server

When you copy data from and to SQL Server, the following mappings are used from SQL Server data types to Azure Data Factory interim data types. To learn how the copy activity maps the source schema and data type to the sink, see Schema and data type mappings.

SQL Server data type Azure Data Factory interim data type
bigint Int64
binary Byte[]
bit Boolean
char String, Char[]
date DateTime
Datetime DateTime
datetime2 DateTime
Datetimeoffset DateTimeOffset
Decimal Decimal
FILESTREAM attribute (varbinary(max)) Byte[]
Float Double
image Byte[]
int Int32
money Decimal
nchar String, Char[]
ntext String, Char[]
numeric Decimal
nvarchar String, Char[]
real Single
rowversion Byte[]
smalldatetime DateTime
smallint Int16
smallmoney Decimal
sql_variant Object
text String, Char[]
time TimeSpan
timestamp Byte[]
tinyint Int16
uniqueidentifier Guid
varbinary Byte[]
varchar String, Char[]
xml Xml

Note

For data types that map to the Decimal interim type, currently Azure Data Factory supports precision up to 28. If you have data that requires precision larger than 28, consider converting to a string in a SQL query.

Lookup activity properties

To learn details about the properties, check Lookup activity.

GetMetadata activity properties

To learn details about the properties, check GetMetadata activity

Troubleshoot connection issues

  1. Configure your SQL Server instance to accept remote connections. Start SQL Server Management Studio, right-click server, and select Properties. Select Connections from the list, and select the Allow remote connections to this server check box.

    Enable remote connections

    For detailed steps, see Configure the remote access server configuration option.

  2. Start SQL Server Configuration Manager. Expand SQL Server Network Configuration for the instance you want, and select Protocols for MSSQLSERVER. Protocols appear in the right pane. Enable TCP/IP by right-clicking TCP/IP and selecting Enable.

    Enable TCP/IP

    For more information and alternate ways of enabling TCP/IP protocol, see Enable or disable a server network protocol.

  3. In the same window, double-click TCP/IP to launch the TCP/IP Properties window.

  4. Switch to the IP Addresses tab. Scroll down to see the IPAll section. Write down the TCP Port. The default is 1433.

  5. Create a rule for the Windows Firewall on the machine to allow incoming traffic through this port.

  6. Verify connection: To connect to SQL Server by using a fully qualified name, use SQL Server Management Studio from a different machine. An example is "<machine>.<domain>.corp.<company>.com,1433".

Next steps

For a list of data stores supported as sources and sinks by the copy activity in Azure Data Factory, see Supported data stores.