SAP HANA - Select
- Kalpana Malladi
- Aparna Tayi (Unlicensed)
- Lakshmi Manda
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| Snap type: | Read | ||||||
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| Description: | This Snap allows you to fetch data from a database by providing a table name and configuring the connection. The Snap produces the records from the database on its output view, which can then be processed by a downstream Snap. JSON paths can be used in a query and will have values from an incoming document substituted into the query. However, documents missing values for a given JSON path will be written to the Snap's error view. After a query is executed, the query's results are merged into the incoming document overwriting any existing keys' values. The original document is output if there are no results from the query. Queries produced by the Snap have an equivalent format: SELECT * FROM [table] WHERE [where clause] ORDER BY [ordering] LIMIT [limit] OFFSET [offset] If more powerful functionality is desired, then the SAP HANA Execute Snap should be used. Expected upstream Snaps: A dynamic where clause can be defined by providing values upstream. Such as the Mapper Snap can provide constants, pipeline parameters mapped into variables which then can be used in the where clause or even in the table/schema properties. Expected downstream Snaps: The Snap will output one document for every record retrieved, hence any document processing Snap can be used downstream. Expected input: Document that provides values for one or more properties of the Snap or simply for pass through purpose. Expected output: Document for each record retrieved. Special types such as TIMESTAMP, TIME are converted into SnapLogic internal date type representations which then can be consumed by downstream Snaps just like any other data type. Important: The where clause can only use variables, no constants or pipeline parameters. Important The where clause can only use variables, no constants or pipeline parameters. A good example for a where clause is: SALARY =$SALARY (here we use the SALARY variable of the input document). | ||||||
| Prerequisites: | |||||||
| Support and limitations: | Works in Ultra Tasks. | ||||||
| Account: | This Snap uses account references created on the Accounts page of SnapLogic Manager to handle access to this endpoint. See Configuring SAP HANA Accounts for information on setting up this type of account. | ||||||
| Views: |
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Settings | |||||||
Label | Required. The name for the Snap. You can modify this to be more specific, especially if you have more than one of the same Snap in your pipeline. | ||||||
Schema name | The database schema name. In case it is not defined, then the suggestion for the table name will retrieve all tables names of all schemas. The property is suggest-able and will retrieve available database schemas during suggest values. Example: myschema Default value: [None] | ||||||
Table name | Required. The name of the table to execute a select query on. Example: people Default value: [None] | ||||||
Where clause | Where clause of select statement. This supports document value substitution (such as $person.firstname will be substituted with the value found in the incoming document at the path). Example: email = 'kalmeida@example.com' or email = $email Default value: [None] | ||||||
Order by | Enter in the columns in order to order by. The default database sort order will be used. Example: name Default value: [None] | ||||||
Limit offset | Starting row for the query. Example: 0 Default value: [None] | ||||||
Limit rows | Number of rows to return from the query. Example: 10 Default value: [None] | ||||||
Output fields | Enter or select output field names for SQL SELECT statement. To select all fields, leave it at default. Example: email, address, first, last, etc. Default value: [None] | ||||||
| Fetch Output Fields In Schema | Select this check box to include only the selected fields or columns in the Output Schema (second output view). If you do not provide any Output fields, all the columns are visible in the output. Default value: Not selected | ||||||
Pass through | If checked, the input document will be passed through to the output view under the key 'original'. Default value: Selected | ||||||
| Ignore empty result | If checked, no document will be written to the output view when the SELECT operation does not produces any result. If this property is unchecked and the Pass through property is checked, the input document will be passed through to the output view. | ||||||
| Auto commit | Select one of the options for this property to override the state of the Auto commit property on the account. The Auto commit at the Snap-level has three values: True, False, and Use account setting. The expected functionality for these modes are:
Default value: False | ||||||
| Match data types | Conditional. This property applies only when the Output fields property is provided with any field value(s). If this property is selected, the Snap tries to match the output data types same as when the Output fields property is empty (SELECT * FROM ...). The output preview would be in the same format as the one when SELECT * FROM is implied and all the contents of the table are displayed. Default value: Not selected | ||||||
Number of retries | Specifies the maximum number of attempts to be made to receive a response. The request is terminated if the attempts do not result in a response. If the value is larger than 0, the Snap first downloads the target file into a temporary local file. If any error occurs during the download, the Snap waits for the time specified in the Retry interval and attempts to download the file again from the beginning. When the download is successful, the Snap streams the data from the temporary file to the downstream Pipeline. All temporary local files are deleted when they are no longer needed. Ensure that the local drive has sufficient free disk space to store the temporary local file. Example: 3 Default value: 0 | ||||||
| Retry interval (seconds) | Specifies the time interval between two successive retry requests. A retry happens only when the previous attempt resulted in an exception. Example: 10 Default value: 1 | ||||||
| Staging mode | Required when the value in the Number of retries field is greater than 0. Specify the location from the following options to store input documents between retries:
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Snap Execution | Select one of the following three modes in which the Snap executes:
Default Value: Execute only | ||||||
Examples
In this example, we show how to retrieve data from a table called "USER".
We can pass the dynamic variable used in where clause from upstream Snap like JSON Generator. We try to retrieve employees by their age.
The sample output looks like:
Snap Pack History
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