Copy and transform data in Azure Database for MySQL using Azure Data Factory or Synapse Analytics

APPLIES TO: Azure Data Factory Azure Synapse Analytics

This article outlines how to use Copy Activity in Azure Data Factory or Synapse Analytics pipelines to copy data from and to Azure Database for MySQL, and use Data Flow to transform data in Azure Database for MySQL. To learn more, read the introductory articles for Azure Data Factory and Synapse Analytics.

This connector is specialized for Azure Database for MySQL service. To copy data from generic MySQL database located on-premises or in the cloud, use MySQL connector.

Supported capabilities

This Azure Database for MySQL connector is supported for the following activities:

Getting started

To perform the Copy activity with a pipeline, you can use one of the following tools or SDKs:

Create a linked service to Azure Database for MySQL using UI

Use the following steps to create a linked service to Azure Database for MySQL in the Azure portal UI.

  1. Browse to the Manage tab in your Azure Data Factory or Synapse workspace and select Linked Services, then click New:

  2. Search for MySQL and select the Azure Database for MySQL connector.

    Select the Azure Database for MySQL connector.

  3. Configure the service details, test the connection, and create the new linked service.

    Configure a linked service to Azure Database for MySQL.

Connector configuration details

The following sections provide details about properties that are used to define Data Factory entities specific to Azure Database for MySQL connector.

Linked service properties

The following properties are supported for Azure Database for MySQL linked service:

Property Description Required
type The type property must be set to: AzureMySql Yes
connectionString Specify information needed to connect to the Azure Database for MySQL instance.
You can also put password in Azure Key Vault and pull the password configuration out of the connection string. Refer to the following samples and Store credentials in Azure Key Vault article with more details.
Yes
connectVia The Integration Runtime to be used to connect to the data store. You can use Azure Integration Runtime or Self-hosted Integration Runtime (if your data store is located in private network). If not specified, it uses the default Azure Integration Runtime. No

A typical connection string is Server=<server>.mysql.database.azure.com;Port=<port>;Database=<database>;UID=<username>;PWD=<password>. More properties you can set per your case:

Property Description Options Required
SSLMode This option specifies whether the driver uses TLS encryption and verification when connecting to MySQL. E.g. SSLMode=<0/1/2/3/4> DISABLED (0) / PREFERRED (1) (Default) / REQUIRED (2) / VERIFY_CA (3) / VERIFY_IDENTITY (4) No
UseSystemTrustStore This option specifies whether to use a CA certificate from the system trust store, or from a specified PEM file. E.g. UseSystemTrustStore=<0/1>; Enabled (1) / Disabled (0) (Default) No

Example:

{
    "name": "AzureDatabaseForMySQLLinkedService",
    "properties": {
        "type": "AzureMySql",
        "typeProperties": {
            "connectionString": "Server=<server>.mysql.database.azure.com;Port=<port>;Database=<database>;UID=<username>;PWD=<password>"
        },
        "connectVia": {
            "referenceName": "<name of Integration Runtime>",
            "type": "IntegrationRuntimeReference"
        }
    }
}

Example: store password in Azure Key Vault

{
    "name": "AzureDatabaseForMySQLLinkedService",
    "properties": {
        "type": "AzureMySql",
        "typeProperties": {
            "connectionString": "Server=<server>.mysql.database.azure.com;Port=<port>;Database=<database>;UID=<username>;",
            "password": { 
                "type": "AzureKeyVaultSecret", 
                "store": { 
                    "referenceName": "<Azure Key Vault linked service name>", 
                    "type": "LinkedServiceReference" 
                }, 
                "secretName": "<secretName>" 
            }
        },
        "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 Azure Database for MySQL dataset.

To copy data from Azure Database for MySQL, set the type property of the dataset to AzureMySqlTable. The following properties are supported:

Property Description Required
type The type property of the dataset must be set to: AzureMySqlTable Yes
tableName Name of the table in the MySQL database. No (if "query" in activity source is specified)

Example

{
    "name": "AzureMySQLDataset",
    "properties": {
        "type": "AzureMySqlTable",
        "linkedServiceName": {
            "referenceName": "<Azure MySQL linked service name>",
            "type": "LinkedServiceReference"
        },
        "typeProperties": {
            "tableName": "<table name>"
        }
    }
}

Copy activity properties

For a full list of sections and properties available for defining activities, see the Pipelines article. This section provides a list of properties supported by Azure Database for MySQL source and sink.

Azure Database for MySQL as source

To copy data from Azure Database for MySQL, 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: AzureMySqlSource Yes
query Use the custom SQL query to read data. For example: "SELECT * FROM MyTable". No (if "tableName" in dataset is specified)
queryCommandTimeout The wait time before the query request times out. Default is 120 minutes (02:00:00) No

Example:

"activities":[
    {
        "name": "CopyFromAzureDatabaseForMySQL",
        "type": "Copy",
        "inputs": [
            {
                "referenceName": "<Azure MySQL input dataset name>",
                "type": "DatasetReference"
            }
        ],
        "outputs": [
            {
                "referenceName": "<output dataset name>",
                "type": "DatasetReference"
            }
        ],
        "typeProperties": {
            "source": {
                "type": "AzureMySqlSource",
                "query": "<custom query e.g. SELECT * FROM MyTable>"
            },
            "sink": {
                "type": "<sink type>"
            }
        }
    }
]

Azure Database for MySQL as sink

To copy data to Azure Database for MySQL, 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: AzureMySqlSink Yes
preCopyScript Specify a SQL query for the copy activity to execute before writing data into Azure Database for MySQL in each run. You can use this property to clean up the preloaded data. No
writeBatchSize Inserts data into the Azure Database for MySQL table when the buffer size reaches writeBatchSize.
Allowed value is integer representing number of rows.
No (default is 10,000)
writeBatchTimeout Wait time for the batch insert operation to complete before it times out.
Allowed values are Timespan. An example is 00:30:00 (30 minutes).
No (default is 00:00:30)

Example:

"activities":[
    {
        "name": "CopyToAzureDatabaseForMySQL",
        "type": "Copy",
        "inputs": [
            {
                "referenceName": "<input dataset name>",
                "type": "DatasetReference"
            }
        ],
        "outputs": [
            {
                "referenceName": "<Azure MySQL output dataset name>",
                "type": "DatasetReference"
            }
        ],
        "typeProperties": {
            "source": {
                "type": "<source type>"
            },
            "sink": {
                "type": "AzureMySqlSink",
                "preCopyScript": "<custom SQL script>",
                "writeBatchSize": 100000
            }
        }
    }
]

Mapping data flow properties

When transforming data in mapping data flow, you can read and write to tables from Azure Database for MySQL. For more information, see the source transformation and sink transformation in mapping data flows. You can choose to use an Azure Database for MySQL dataset or an inline dataset as source and sink type.

Source transformation

The below table lists the properties supported by Azure Database for MySQL source. You can edit these properties in the Source options tab.

Name Description Required Allowed values Data flow script property
Table If you select Table as input, data flow fetches all the data from the table specified in the dataset. No - (for inline dataset only)
tableName
Query If you select Query as input, specify a SQL query to fetch data from source, which overrides any table you specify in dataset. Using queries is a great way to reduce rows for testing or lookups.

Order By clause is not supported, 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 that you can use in data flow.
Query example: select * from mytable where customerId > 1000 and customerId < 2000 or select * from "MyTable".
No String query
Batch size Specify a batch size to chunk large data into batches. No Integer batchSize
Isolation Level Choose one of the following isolation levels:
- Read Committed
- Read Uncommitted (default)
- Repeatable Read
- Serializable
- None (ignore isolation level)
No READ_COMMITTED
READ_UNCOMMITTED
REPEATABLE_READ
SERIALIZABLE
NONE
isolationLevel

Azure Database for MySQL source script example

When you use Azure Database for MySQL as source type, the associated data flow script is:

source(allowSchemaDrift: true,
    validateSchema: false,
    isolationLevel: 'READ_UNCOMMITTED',
    query: 'select * from mytable',
    format: 'query') ~> AzureMySQLSource

Sink transformation

The below table lists the properties supported by Azure Database for MySQL sink. You can edit these properties in the Sink options tab.

Name Description Required Allowed values Data flow script property
Update method Specify what operations are allowed on your database destination. The default is to only allow inserts.
To update, upsert, or delete rows, an Alter row transformation is required to tag rows for those actions.
Yes true or false deletable
insertable
updateable
upsertable
Key columns For updates, upserts and deletes, key column(s) must be set to determine which row to alter.
The column name that you pick as the key will be used as part of the subsequent update, upsert, delete. Therefore, you must pick a column that exists in the Sink mapping.
No Array keys
Skip writing key columns If you wish to not write the value to the key column, select "Skip writing key columns". No true or false skipKeyWrites
Table action Determines whether to recreate or remove all rows from the destination table prior to writing.
- None: No action will be done to the table.
- Recreate: The table will get dropped and recreated. Required if creating a new table dynamically.
- Truncate: All rows from the target table will get removed.
No true or false recreate
truncate
Batch size Specify how many rows are being written in each batch. Larger batch sizes improve compression and memory optimization, but risk out of memory exceptions when caching data. No Integer batchSize
Pre and Post SQL scripts Specify multi-line SQL scripts that will execute before (pre-processing) and after (post-processing) data is written to your Sink database. No String preSQLs
postSQLs

Azure Database for MySQL sink script example

When you use Azure Database for MySQL as sink type, the associated data flow script is:

IncomingStream sink(allowSchemaDrift: true,
    validateSchema: false,
    deletable:false,
    insertable:true,
    updateable:true,
    upsertable:true,
    keys:['keyColumn'],
    format: 'table',
    skipDuplicateMapInputs: true,
    skipDuplicateMapOutputs: true) ~> AzureMySQLSink

Lookup activity properties

To learn details about the properties, check Lookup activity.

Data type mapping for Azure Database for MySQL

When copying data from Azure Database for MySQL, the following mappings are used from MySQL data types to interim data types used internally within the service. See Schema and data type mappings to learn about how copy activity maps the source schema and data type to the sink.

Azure Database for MySQL data type Interim service data type
bigint Int64
bigint unsigned Decimal
bit Boolean
bit(M), M>1 Byte[]
blob Byte[]
bool Int16
char String
date Datetime
datetime Datetime
decimal Decimal, String
double Double
double precision Double
enum String
float Single
int Int32
int unsigned Int64
integer Int32
integer unsigned Int64
long varbinary Byte[]
long varchar String
longblob Byte[]
longtext String
mediumblob Byte[]
mediumint Int32
mediumint unsigned Int64
mediumtext String
numeric Decimal
real Double
set String
smallint Int16
smallint unsigned Int32
text String
time TimeSpan
timestamp Datetime
tinyblob Byte[]
tinyint Int16
tinyint unsigned Int16
tinytext String
varchar String
year Int32

Next steps

For a list of data stores supported as sources and sinks by the copy activity, see supported data stores.