Teradata Select

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Snap type:

Read

Description:

The Teradata Select Snap allows you to fetch data from an Teradata 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 the format:

SELECT TOP [limit] * FROM [table] WHERE [where clause] ORDER BY [ordering]


If more powerful functionality is desired, then the 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 down stream.
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.

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)
A bad example for a where clause is: SALARY = _param (this will not work since we do not evaluate pipeline parameters during prepared statement execution, instead an upstream mapper needs to be used that maps _param into $SALARY) 

Prerequisites:

[None]

Support and limitations:

Works in Ultra Task Pipelines.

Account: 

This Snap uses account references created on the Accounts page of SnapLogic Manager to handle access to this endpoint. See Configuring Teradata Database Accounts for information on setting up this type of account.

Views:
InputThis Snap has one output view by default and produces one Document for each record in the table.  A second view can be added to dump out the metadata for the table as a Document. 
Output

This Snap has at most one error view and produces zero or more Document(s) in the view.

ErrorThis Snap has at most one error view and produces zero or more Document(s) in the view.

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: SYS
Default value: None 

Table name

Name of table to execute 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). However, you may not use a value substitution after "IS" or "is" word. Please see the examples below.

Examples

Without using expressions

  • email = 'you@example.com' or email = $email 
  • emp=$emp

Using expressions

  • "EMPNO=$EMPNO and ENAME=$EMPNAME"
  • "emp='" + $emp + "'"
  • "EMPNO=" + $EMPNO + " and ENAME='" + $EMPNAME+ "'"

Caution

Using expressions that join strings together to create SQL queries or conditions has a potential SQL injection risk and hence unsafe. Ensure that you understand all implications and risks involved before using concatenation of strings with '=' Expression enabled. 


Order by columns

Enter in the columns in order to order by. The default database sort order will be used.

Example

name

email

Default value: None 

Limit offset


Starting row for the query

Example: 0

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.
If you provide output fields, we recommend you to select Fetch Output Fields In Schema check box.

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.

Default value: False

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: TrueFalse, and Use account setting. The expected functionality for these modes are:

  •  True - The Snap will execute with auto-commit enabled regardless of the value set for Auto commit in the Account used by the Snap.
  •  False - The Snap will execute with auto-commit disabled regardless of the value set for Auto commit in the Account used by the Snap.
  • Use account setting - The Snap will execute with Auto commit property value inherited by the Account used by the Snap.

Default value: Use account setting

Snap Execution

Select 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.

For the 'Suggest' in the Order by columns and the Output fields properties, the value of the Table name property should be an actual table name instead of an expression. If it is an expression, it will display an error message "Could not evaluate accessor:  ..." when the 'Suggest' button is pressed. This is because, at the time of "Suggest" button pressed, the input document is not available for the Snap to evaluate the expression in the Table name property. The input document is available to the Snap only during the preview or execution time.

Example

In this basic pipeline, the Teradata Snap selects the records from the table, 'snaplogic"."employee1' with the defined order and the output fields.

The successful execution of the pipeline displays the below output preview:

Snap Pack History

 Click to view/expand
Release Snap Pack VersionDateType  Updates
4.29main15993 Stable

Enhanced the Teradata FastExport Snap with Character Set dropdown list to support encoding of data when you export data from the Teradata database.

4.28main14627 StableUpgraded with the latest SnapLogic Platform release.
4.27main12833 Stable

Enhanced the Teradata Execute Snap to invoke stored procedures.

4.26main11181 StableUpgraded with the latest SnapLogic Platform release.
4.25 Patch425patches11008 Latest

Improved the error messages for all the Snaps in the Teradata Snap Pack where the Snaps fail with a null pointer exception error when the account reference provided is invalid. 

4.25main9554
 
StableUpgraded with the latest SnapLogic Platform release.

4.24 Patch

424patches8799 Latest
  • Enhanced the Teradata Execute Snap by adding a new field, Advanced options, which extends support with microsecond precision for TIMESTAMP data type.
  • Fixed an issue in the TPT Load Snap where the Snap failed to load data into the table while creating an output.
  • Fixed an issue with the TPT Load Snap wherein now a null value is loaded as null and empty string is loaded as empty string.

    • This fix may cause existing pipelines to fail if empty string values are expected to be loaded as null.

    • Following are the new configurations:

      • VARCHAR QuotedData= Optional

      • VARCHAR OpenQuoteMark= \”

      • VARCHAR NullColumns= Yes

4.24main8556
Stable

Enhanced the Teradata Select Snap to return only the selected output fields or columns in the output schema (second output view) using the Fetch Output Fields In Schema check box. If the Output Fields field is empty all the columns are visible.

4.23main7430
 
Stable

Fixes the multi-line value issue and issue in the TPT Load Snap where the Snap writes null for both an empty string and null values in the input data. The fix for this issue was to add the following three lines in the script and wrap all the values in double quotes unless they are null while writing the input data into a temp CSV file. 
VARCHAR QuotedData = 'Optional',
VARCHAR OpenQuoteMark = '\"'
VARCHAR NullColumns = 'Yes'

This fix may cause existing pipelines to fail if empty string values are expected to be loaded as null.



4.22main6403
 
StableUpgraded with the latest SnapLogic Platform release.

4.21 Patch

421patches6272 Latest

Fixed the issue where Snowflake SCD2 Snap generates two output documents despite no changes to Cause-historization fields with DATE, TIME and TIMESTAMP Snowflake data types, and with Ignore unchanged rows field selected.

4.21 Patch

421patches6144 Latest

Fixed the following issues with DB Snaps:

  • The connection thread waits indefinitely causing the subsequent connection requests to become unresponsive.
  • Connection leaks occur during Pipeline execution.

4.21 Patch

MULTIPLE8841 Latest

Fixed the connection issue in Database Snaps by detecting and closing open connections after the Snap execution ends. 

4.21snapsmrc542

 

StableUpgraded with the latest SnapLogic Platform release.
4.20snapsmrc535
 
StableUpgraded with the latest SnapLogic Platform release.

4.19 Patch 

db/teradata8414 LatestFixed an issue with the TPT Update Snap wherein the Snap is unable to perform operations when:
  • An expression is used in the Update condition property.
  • Input data contain the character '?'.
4.19snaprsmrc528
 
StableUpgraded with the latest SnapLogic Platform release.
4.18snapsmrc523
 
StableUpgraded with the latest SnapLogic Platform release.
4.17ALL7402
 
Latest

Pushed automatic rebuild of the latest version of each Snap Pack to SnapLogic UAT and Elastic servers.

4.17snapsmrc515
 
Latest
  • Fixed an issue with the Teradata Execute Snap wherein the Snap would send the input document to the output view even if the Pass through field is not selected in the Snap configuration. With this fix, the Snap sends the input document to the output view, under the key original, only if you select the Pass through field.
  • Added the Snap Execution field to all Standard-mode Snaps. In some Snaps, this field replaces the existing Execute during preview check box.
4.16snapsmrc508
 
StableUpgraded with the latest SnapLogic Platform release.

4.15 Patch 

db/teradata6338 Latest

Replaced Max idle time and Idle connection test period properties with Max life time and Idle Timeout properties respectively, in the Account configuration. The new properties fix the connection release issues that were occurring due to default/restricted DB Account settings.

4.15snapsmrc500
 
StableUpgraded with the latest SnapLogic Platform release.
4.14snapsmrc490
 
StableUpgraded with the latest SnapLogic Platform release.
4.13

snapsmrc486

 
StableUpgraded with the latest SnapLogic Platform release.
4.12

snapsmrc480

 
StableUpgraded with the latest SnapLogic Platform release.
4.11snapsmrc465
 
StableUpgraded with the latest SnapLogic Platform release.
4.10

snapsmrc414

 
Stable

Added Auto commit property to the Select and Execute Snaps at the Snap level to support overriding of the Auto commit property at the Account level.

4.9.0 Patch

teradata3077 Latest

Fixed an issue regarding connection not closed after login failure; Expose autocommit for "Select into" statement in PostgreSQL Execute Snap and Redshift Execute Snap

4.9snapsmrc405
 
Stable
  • Enhanced the Output view of the Snap with Order Summary field that displays the output values (added to the out, err, status, classpath and env fields of the single output view that display the subprocess only).
  • Teradata Export to HDFS Snap supported with Dynamic account.
4.8

snapsmrc398

 
Stable
  • Introduced the TPT Delete, Insert, Load, Upsert and Update Snaps in this release.
  • Introduced Teradata Export to HDFS Snap in this release.
  • Info tab added to accounts.
  • Database accounts now invalidate connection pools if account properties are modified and login attempts fail.
4.7

snapsmrc382

 
Stable
  • Introduced the Teradata FastLoad and Execute Snaps in this release.
  • Migration impact: In Teradata FastExport, the values of the Data Format field have been standardized to be in all caps. Existing pipelines that use the values of Binary, Text, or Unformatted will fail unless the new value of BINARY, TEXT, or UNFORMAT are used.
4.6snapsmrc362
 
Stable

Snap Pack introduced in 4.6.0. This includes only Teradata extract functionality to move data out of Teradata database using the FastExport Utility. It does not include Snaps for load, select, insert, delete, execute or others at this time. It also does not utilize the Teradata Parallel Transporter to extract data.