MySQL Lookup
Overview
This Snap provides functionality to lookup records in the target MySQL table and return a selected set of fields for every matched record. The Snap executes one request per multiple input documents to avoid making a request for every input record.
JSON paths can be used in the Snap properties and will have values from an incoming document substituted into the properties. 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.
Queries produced by the Snap have the format:
SELECT [Output fields] FROM [Table name] WHERE
[C1 = V11 AND C2 = V21 AND...[Cn = Vn1] OR
[C1 = V12 AND C2 = V22 AND...[Cn = Vn2] OR
...................................... OR
[Cn = V1n AND Cm = V2m AND...[Cn = Vnm]The Snap ignores any duplicated lookup condition in the input document stream since it maintains a cache for lookup conditions internally.
Expected upstream Snaps: Any Snap which produces documents in the output view, such as CSV Parser, JSON Parser, Structure, Mapper.
Expected downstream Snaps: Any Snap which receives documents in the input view, such as JSON Formatter, Structure, Mapper. The CSV Formatter will cause an error since the output data is not a flattened Map data.
Expected input: Each document in the input view should contain a Map data of key-value entries. Input data may contain values needed to evaluate expressions in the Object type, Output fields and Conditions properties. If the Pass-though on no lookup match property is unchecked, please make sure input data types match column data types in the database table. Otherwise, you may encounter an error message "Cannot find an input data which is related to the output record .....". If the error view is open, all input data in the batch are routed to the error view with the same error information.
Expected output: Each document in the output view contains a Map data of key-value entries, where keys are the Output fields property values. The input data that has produced the corresponding output data is also included in the output data under the "original" key.
- This is a Read-type Snap.
Works in Ultra Tasks
Prerequisites
[None]
Limitations
Works in Ultra Tasks with pass-through.
When MySQL execute Snaps (MySQL Execute and MySQL Multi Execute) are followed by MySQL non-execute Snaps, such as MySQL Insert, MySQL Merge, and so on, the following error is displayed when executed:
Table definition has changed, please retry transaction.
This happens due to a known issue in the MySQL Connector. For more information about this issue, see MySQL Bug #65378.
Snap views
| Type | Description | Examples of upstream and downstream Snaps |
|---|---|---|
| Input | This Snap has exactly one document input view. Each document should have values for one AND clause in the WHERE statement. | |
| Output | This Snap has exactly one document output view. The output document includes the corresponding input data under the "original" key. If there is no results from the query, each output field will have null value. | |
| Error | This Snap has at most one document error view and produces zero or more documents in the view. |
Snap settings
- 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.
| Field/Field set | Description |
|---|---|
Label
String |
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 suggestable and will retrieve available database schemas during suggest values.
The values can be passed using the pipeline parameters but not the upstream parameter. Example: SYS Default value: [None] |
| Table name
|
Required.Enter or select the name of SQL table to execute the lookup query on.
The values can be passed using the pipeline parameters but not the upstream parameter. Example: people Default value: [None] |
| Output fields
|
Required.Enter or select output field names for SQL SELECT statement.
Example: email, address, first, last Default value: [None] |
| Lookup conditions | Required.The lookup conditions are created by using the lookup column name and the lookup column value. Each row will build a condition, such as lookupColumn1 = $inputField. Each additional row will be concatenated using a logical AND. All rows together build the lookup condition being used to lookup records in the lookup table.
|
| Pass-through on no lookup match
|
When there is no lookup matching an input document, the input document will pass through to the output view if this property is checked. Otherwise, it will be written to the error view as an error condition.
Default value: False |
Snap execution
Dropdown list |
Choose one of the three modes in
which the Snap executes. Available options are:
|