Databricks - Merge Into

Overview

You can use this Snap to run a MERGE INTO SQL statement based on the updates available in the source data files. In other words, this Snap allows you to perform a bulk UPSERT (UPDATE + INSERT) operation to update existing rows of a target DLP table and add new rows to the target table. The source of your data can be a file from a cloud storage location, an input view from an upstream Snap, or a table that can be accessed through a JDBC connection. The source data can be in a CSV, JSON, PARQUET, TEXT, or an ORC file.

This Snap uses the following Databricks commands internally:

COPY INTO - Enables loading data from staged files to an existing table.
CREATE TABLE [USING] - Enables loading data from some external sources like JDBC.
CREATE TABLE - Creates table in our case temporary table.
MERGE INTO - Inserts new rows, updates existing rows and delete by condition rows.

Write-type Snap
Does not support Ultra Tasks

Prerequisites

Valid access credentials to a DLP instance with adequate access permissions to perform the action in context.
Valid access to the external source data in one of the following: Azure Blob Storage, ADLS Gen2, DBFS, GCP, AWS S3, or another database (JDBC-compatible).

Limitations

Snaps in the Databricks Snap Pack do not support array, map, and struct data types in their input and output documents.

Snap views


View	Description	Examples of upstream and downstream Snaps
Input	This Snap can read from two input documents at a time: One JSON document for the incoming data from the preceding Snap in the Pipeline. Another JSON document that serves as the data source when Source Type is selected as Input View.	Mapper Copy JSON Generator Databricks - Select
Output	A JSON document containing the bulk load request details and the result of the bulk load operation.	Databricks - Select Databricks - Unload
Error	Error handling is a generic way to handle errors without losing data or failing the Snap execution. You can handle the errors that the Snap might encounter when running the pipeline by choosing one of the following options from the When errors occur list under the Views tab. The available options are: Stop Pipeline Execution Stops the current pipeline execution when an error occurs. Discard Error Data and Continue Ignores the error, discards that record, and continues with the remaining records. Route Error Data to Error View Routes the error data to an error view without stopping the Snap execution. Learn more about Error handling in Pipelines.

Snap settings

Legend:

Expression icon (): Allows using pipeline parameters to set field values dynamically (if enabled). SnapLogic Expressions are not supported. If disabled, you can provide a static value.
SnapGPT (): Generates SnapLogic Expressions based on natural language using SnapGPT. Learn more.
Suggestion icon (): Populates a list of values dynamically based on your Snap configuration. You can select only one attribute at a time using the icon. Type into the field if it supports a comma-separated list of values.
Upload : Uploads files. Learn more.

Learn more about the icons in the Snap settings dialog.


Field / Field set	Type	Description
Label	String	Required. Specify a unique name for the Snap. Modify this to be more appropriate, especially if more than one of the same Snaps is in the pipeline. Default value: Databricks - Merge Into Example: Db_MergeInto_FromS3
Use unity catalog	Checkbox	Select this checkbox to use the Unity catalog to access data from the catalog. Default status: Deselected
Catalog name	String/Expression/ Suggestion	Appears when you select Use unity catalog. Specify the name of the catalog for using the unity catalog. Default value: hive_metastore Example: xyzcatalog
Database name	String/Expression/ Suggestion	Enter the name of the database in which the target table exists. Leave this blank if you want to use the database name specified in the Database Name field in the account settings. Default value: None. Example: cust_db
Table name	String/Expression/ Suggestion	Required. Enter the name of the table in which you want to perform the MERGE INTO operation. Default value: None. Example: cust_records
Target Table Alias	String	Required. Enter an alias name for the target table to use in the MERGE INTO operation. Default value: None. Example: trgt_tbl
Input Source Alias	String	Required. Enter an alias name for the source table/data to use in the MERGE INTO operation. Default value: None. Example: src_tbl
ON Condition	String/Suggestion	Required. Specify the condition on which the Snap should update the target table with the data from the source table/files. Default value: None. Example: src.id=trg.id
Merge-into Statements	You can use this field set to specify the conditions that activate the MERGE INTO operation and the additional conditions that must be met. Specify each condition in a separate row. This field set contains the following fields: When Clause Condition Action Note: The Snap allows the following combinations of actions: INSERT UPDATE DELETE UPDATE AND DELETE UPDATE AND INSERT DELETE AND INSERT UPDATE, DELETE AND INSERT
When Clause	String/Expression/ Suggestion	Specify the matching condition based on the outcome of the ON Condition. Alternatively, select a clause from the suggestion list. Available options are: WHEN MATCHED: Applies the specified condition and action when the source data matches with the target. WHEN NOT MATCHED: Applies the specified condition and action when the source data does not match with the target. DLP supports the following MERGE INTO operations: WHEN MATCHED: UPDATE or DELETE WHEN NOT MATCHED: INSERT Default value: None. Example: WHEN MATCHED
Condition	String/Expression	Specify the additional criteria if needed. The action associated for the specified condition is not performed if the condition's criteria is not fulfilled. It can be a combination of both source and target tables, source table only, target table only, or may not contain references to any table at all. Having this additional condition allows the Snap to identify whether the UPDATE or DELETE action must be performed (since both the actions correspond to the WHEN MATCHED clause). You can also use Pipeline parameters in this field to bind values. However, you must be careful to avoid SQL injection. Default value: None. Example: net-value > 5000
Action	Dropdown list	Choose the action to apply on the condition. Available options are: INSERT UPDATE DELETE Default value: INSERT Example: DELETE
Source Type	Dropdown list	Select the type of source from which you want to update the data in your DLP instance. The available options are: Cloud Storage File. A file from a cloud location like AWS S3, Azure, or GCS. You can configure a series of options for the MERGE INTO operation as described in this document. Input View. A JSON file coming from the preceding Snap’s output. You need to specify only the Load action. If selected, you can see the Retry options to specify the maximum number of retry attempts that Snap can complete when it fails to write. JDBC. A table in another database that can be connected to using a JDBC connector. You can specify the Source table name to load the data from or the Target Table Columns to replace the existing target table with a new one. Default value: Cloud Storage File Example: Input View
Source table name	String	Appears when the Source Type is JDBC. Enter the source table name. The default values (database) configured in the Snap’s account for JDBC Account type are considered, if not specified in this field.
File format type	Dropdown list	Appears when the Source Type is Cloud Storage file. Select the file format of the source data file. It can be CSV, JSON, ORC, PARQUET, or TEXT. Default value: CSV Example: PARQUET
File Format Option List	Appears when the Source Type is Cloud Storage file. You can use this field set to choose the file format options to associate with the MERGE INTO operation, based on your source file format. Choose one file format option in each row.
File format option	String/Expression/ Suggestion	Appears when the Source Type is Cloud Storage file. Select a file format option from the available options and set appropriate values to suit your MERGE INTO needs, without affecting the syntax displayed in this field. Default value: None. Example: cust_ID
Files provider	Dropdown list	Appears when the Source Type is Cloud Storage file. Declare the manner in which you are specifying the source files list - File list or pattern. Based on your selection in this field, the corresponding fields change: File list fieldset for File list and File pattern field for pattern. Default value: File list Example: pattern
File list	Appears when the Source Type is Cloud Storage file and Files provider is File list. You can use this field set to specify the file paths to be used for the MERGE INTO operation. Choose one file path in each row.
File	String	Appears when the Source Type is Cloud Storage file and Files provider is File list. Enter the path of the file to be used for the MERGE INTO operation. Default value: None. Example: cust_data.csv
File pattern	String/Expression	Appears when the Source Type is Cloud Storage file and Files provider is pattern. Enter the regex pattern to use to match the file name and/or absolute path. You can specify this as a regular expression pattern string, enclosed in single quotes. Learn more: Examples of COPY INTO (Delta Lake on Databricks) for DLP. Default value: None. Example: folder1/.csv*
Encryption type	String/Expression/ Suggestion	Appears when the Source Type is Cloud Storage file. Select the encryption type to use for decrypting the source data and/or files staged in the S3 buckets. Note: Server-side encryption is available only for S3 accounts. Default value: None. Example: Server-Side KMS Encryption
KMS key	String/Expression	Source Type is Cloud Storage file and Encryption type is Server-Side KMS Encryption. Enter the AWS Key Management Service (KMS) ID or ARN to use to decrypt the encrypted files from the S3 location. In case that your source files are in S3, see Loading encrypted files from Amazon S3 for more detail. Default value: None. Example: MF96D-M9N47-XKV7X-C3GCQ-G5349
Number of Retries	Integer/Expression	Specifies the maximum number of retry attempts when the Snap fails to write. Minimum value: 0 Default value: 0 Example: 3
Retry Interval (seconds)	Integer/Expression	Source Type is Input View Specifies the minimum number of seconds the Snap must wait before each retry attempt. Minimum value: 1 Default value: 1 Example: 3
Manage Queued Queries	Dropdown list	Select this property to determine whether the Snap should continue or cancel the execution of the queued Databricks SQL queries when you stop the Pipeline. Note: If you select Cancel queued queries when pipeline is stopped or if it fails, then the read queries under execution are cancelled, whereas the write type of queries under execution are not cancelled. Databricks internally determines which queries are safe to be cancelled and cancels those queries. Warning: Due to an issue with DLP, aborting an ELT Pipeline validation (with preview data enabled) causes only those SQL statements that retrieve data using bind parameters to get aborted while all other static statements (that use values instead of bind parameters) persist. For example, `select * from a_table where id = 10` will not be aborted while `select * from test where id = ?` gets aborted. To avoid this issue, ensure that you always configure your Snap settings to use bind parameters inside its SQL queries. Default value: Continue to execute queued queries when pipeline is stopped or if it fails. Example: Cancel queued queries when pipeline is stopped or if it fails
Snap execution	Dropdown list	Choose one of the three modes in which the Snap executes. Available options are: Validate & Execute: Performs limited execution of the Snap and generates a data preview during pipeline validation. Subsequently, performs full execution of the Snap (unlimited records) during pipeline runtime. Execute only: Performs full execution of the Snap during pipeline execution without generating preview data. Disabled: Disables the Snap and all Snaps that are downstream from it. Default value: Execute only Example: Validate & Execute

Troubleshooting


Error	Reason	Resolution
Missing property value	You have not specified a value for the required field where this message appears.	Ensure that you specify valid values for all required fields.

Examples

Updating Employee List in the DLP instance using a CSV file