Table Input transform Icon Table Input

Description

The Table Input transform is used to read information from a database, using a connection and SQL.

Basic SQL statements can be generated automatically by clicking Get SQL select statement.

SQL queries can be parameterized through variables and can accept input from previous transform fields.

Supported Engines

Hop Engine

Supported

Spark

Maybe Supported

Flink

Maybe Supported

Dataflow

Maybe Supported

Options

Option Description

Transform name

Name of the transform.

Connection

The database connection from which to read data

SQL

The SQL statement used to read information from the database connection. You can also click Get SQL select statement…​ to browse tables and automatically generate a basic select statement.

Enable lazy conversion

When enabled, lazy conversion avoids unnecessary data type conversions and can result in a significant performance improvements.

Replace variables in script?

Enable to replace variables in the script; this feature was provided to allow you to test with or without performing variable substitutions.

Insert data from transform

Specify the input transform name where Hop can expect information to come from. This information can then be inserted into the SQL statement. The locator where Hop inserts information is indicated with a question mark: ?.

Execute for each row?

Enable to perform the data insert for each individual row.

Limit size

Sets the number of lines that is read from the database; zero (0) means read all lines.

Example

Below is a SQL statement:

SELECT * FROM customers WHERE changed_date BETWEEN ? AND ?

This SQL statement requests two calendar dates, to create a range, that are read from the Insert data from transform option. The target date range can be provided using the Get System Info transform. For example, if you want to read all customers that have had their data changed yesterday, you can get a target range for yesterday and read the customer data.