tAmazonMysqlRow

tAmazonMysqlRow properties

Component family	Cloud/Amazon/MySQL
Function	tAmazonMysqlRow is the specific component for this database query. It executes the SQL query stated in the specified database. The row suffix means the component implements a flow in the job design although it doesn’t provide output.
Purpose	Depending on the nature of the query and the database, tAmazonMysqlRow acts on the actual DB structure or on the data (although without handling data). The SQLBuilder tool helps you write easily your SQL statements.
Basic settings	Property type	Either Built-in or Repository. Since version 5.6, both the Built-In mode and the Repository mode are available in any of the Talend solutions.
		Built-in: No property data stored centrally.
		Repository: Select the repository file in which the properties are stored. The fields that follow are completed automatically using the data retrieved.
	DB Version	MySQL 5 is available.
	Use an existing connection	Select this check box and in the Component List click the relevant connection component to reuse the connection details you already defined. Note When a Job contains the parent Job and the child Job, if you need to share an existing connection between the two levels, for example, to share the connection created by the parent Job with the child Job, you have to: In the parent level, register the database connection to be shared in the Basic settings view of the connection component which creates that very database connection. In the child level, use a dedicated connection component to read that registered database connection. For an example about how to share a database connection across Job levels, see Talend Studio User Guide.
	Host	Database server IP address
	Port	Listening port number of DB server.
	Database	Name of the database
	Username and Password	DB user authentication data. To enter the password, click the […] button next to the password field, and then in the pop-up dialog box enter the password between double quotes and click OK to save the settings.
	Schema and Edit Schema	A schema is a row description, that is to say, it defines the number of fields to be processed and passed on to the next component. The schema is either Built-in or stored remotely in the Repository. Since version 5.6, both the Built-In mode and the Repository mode are available in any of the Talend solutions.
		Built-In: You create and store the schema locally for this component only. Related topic: see Talend Studio User Guide.
		Repository: You have already created the schema and stored it in the Repository. You can reuse it in various projects and Job designs. Related topic: see Talend Studio User Guide. When the schema to be reused has default values that are integers or functions, ensure that these default values are not enclosed within quotation marks. If they are, you must remove the quotation marks manually. For more details, see https://help.talend.com/display/KB/Verifying+default+values+in+a+retrieved+schema.
	Table Name	Name of the table to be processed.
	Query type	Either Built-in or Repository. Since version 5.6, both the Built-In mode and the Repository mode are available in any of the Talend solutions.
		Built-in: Fill in manually the query statement or build it graphically using SQLBuilder
		Repository: Select the relevant query stored in the Repository. The Query field gets accordingly filled in.
	Guess Query	Click the Guess Query button to generate the query which corresponds to your table schema in the Query field.
	Query	Enter your DB query paying particularly attention to properly sequence the fields in order to match the schema definition.
	Die on error	This check box is selected by default. Clear the check box to skip the row on error and complete the process for error-free rows. If needed, you can retrieve the rows on error via a Row > Rejects link.
Advanced settings	Additional JDBC parameters	Specify additional connection properties for the DB connection you are creating. This option is not available if you have selected the Use an existing connection check box in the Basic settings.
	Propagate QUERY’s recordset	Select this check box to insert the result of the query in a COLUMN of the current flow. Select this column from the use column list. Note This option allows the component to have a different schema from that of the preceding component. Moreover, the column that holds the QUERY’s recordset should be set to the type of Object and this component is usually followed by tParseRecordSet.
	Use PreparedStatement	Select this check box if you want to query the database using a PreparedStatement. In the Set PreparedStatement Parameter table, define the parameters represented by “?” in the SQL instruction of the Query field in the Basic Settings tab. Parameter Index: Enter the parameter position in the SQL instruction. Parameter Type: Enter the parameter type. Parameter Value: Enter the parameter value. Note This option is very useful if you need to execute the same query several times. Performance levels are increased
	Commit every	Number of rows to be completed before committing batches of rows together into the DB. This option ensures transaction quality (but not rollback) and above all better performance on executions.
	tStatCatcher Statistics	Select this check box to collect log data at the component level.
Dynamic settings	Click the [+] button to add a row in the table and fill the Code field with a context variable to choose your database connection dynamically from multiple connections planned in your Job. This feature is useful when you need to access database tables having the same data structure but in different databases, especially when you are working in an environment where you cannot change your Job settings, for example, when your Job has to be deployed and executed independent of Talend Studio. The Dynamic settings table is available only when the Use an existing connection check box is selected in the Basic settings view. Once a dynamic parameter is defined, the Component List box in the Basic settings view becomes unusable. For more information on Dynamic settings and context variables, see Talend Studio User Guide.
Global Variables	QUERY: the SQL query statement being processed. This is a Flow variable and it returns a string. ERROR_MESSAGE: the error message generated by the component when an error occurs. This is an After variable and it returns a string. This variable functions only if the Die on error check box is cleared, if the component has this check box. A Flow variable functions during the execution of a component while an After variable functions after the execution of the component. To fill up a field or expression with a variable, press Ctrl + Space to access the variable list and choose the variable to use from it. For further information about variables, see Talend Studio User Guide.
Usage	This component offers the flexibility of the DB query and covers all possible SQL queries.
Log4j	The activity of this component can be logged using the log4j feature. For more information on this feature, see Talend Studio User Guide. For more information on the log4j logging levels, see the Apache documentation at http://logging.apache.org/log4j/1.2/apidocs/org/apache/log4j/Level.html.

Scenario 1: Removing and regenerating a MySQL table index

This scenario describes a four-component job that removes a table index, applies a
select insert action onto a table then regenerates the index.

Setting up the Job

Select and drop the following components onto the design workspace:
tAmazonMysqlRow (x2), tRowGenerator, and tAmazonMysqlOutput.
Connect tRowGenerator to tAmazonMysqlOutput.
Using a OnComponentOk connections, link
the first tAmazonMysqlRow to tRowGenerator and tRowGenerator to the second tAmazonMysqlRow.

Configuring the tAmazonMysqlRow component

Select the tAmazonMysqlRow to fill in
the DB Basic settings.
In Property type as well in Schema, select the relevant DB entry in the
list.

The DB connection details and the table schema are accordingly filled in.
Propagate the properties and schema details onto the other components of
the Job.
The query being stored in the Metadata
area of the Repository, you can also select
Repository in the Query type field and the relevant query entry.
If you didn’t store your query in the Repository, type in the following SQL statement to alter the
database entries: drop index <index_name> on <table_name>
Select the second tAmazonMysqlRow
component, check the DB properties and schema.
Type in the SQL statement to recreate an index on the table using the
following statement: create index <index_name> on <table_name>
(<column_name>)

The tRowGenerator component is used to
generate automatically the columns to be added to the DB output table
defined.

Configuring the output component

Select the tAmazonMysqlOutput component
and fill in the DB connection properties> either from the
Repository, or manually for this specific use only. The table
to be fed is named: comprehensive.
The schema should be automatically inherited from the data flow coming
from the tRowGenerator. Edit the schema to
check its structure and check that it corresponds to the schema expected on
the DB table specified.
The Action on table is
None and the Action on
data is Insert.

Job execution

Press F6 to run the job.

If you manage to watch the action on DB data, you can notice that the index is
dropped at the start of the job and recreated at the end of the insert
action.

Scenario 2: Using PreparedStatement objects to query data

This scenario describes a four component job which allows you to link a table column
with a client file. The MySQL table contains a list of all the American States along
with the State ID, while the file contains the customer information including the ID of
the State in which they live. We want to retrieve the name of the State for each client,
using an SQL query. In order to process a large volume of data quickly, we use a
PreparedStatement object which means that the query is executed only once rather than
against each row in turn. Then each row is sentas a parameter.

For this scenario, we use a file and a database for which we have already stored the
connection and properties in the Rerpository metadata. For further information
concerning the creation of metadata in delimited files, the creation of database
connection metadata and the usage of metadata, see Talend Studio User
Guide.

Configuring the input component

In the Repository, expand the Metadata and File
delimited nodes. Select the metadata which corresponds to the
client file you want to use in the Job.

Here, we are using the customers metadata.
Slide the metadata onto the workspace and double-click tFileInputDelimited in the [Components] dialog box so that the tFileInputDelimited component is created with the parameters
already set.
In the Schema list, select Built-in so that you can modify the component’s
schema. Then click on […] next to the
Edit schema field to add a column into
which the name of the State will be inserted.
Click on the [+] button to add a column
to the schema. Rename this column LabelStateRecordSet
and select Object from the Type list. Click OK to save your modifications.
From the Palette, select the tAmazonMysqlRow, tParseRecordSet and tFileOutputDelimited components and drop them onto the
workspace. Connect the four components using Row > Main type
links.

Setting up the DB connection

Double-click tAmazonMysqlRow to set its
properties in the Basic settings tab of the
Component view.
In the Property Type list,
select Repository and click on the
[…] button to select a database
connection from the metadata in the Repository. The DB
Version, Host, Port, Database,
Username and Password fields are completed automatically. If you are
using the Built-in mode, complete these
fields manually.
From the Schema list, select Built-in to set the schema properties manually
and add the LabelStateRecordSet column, or click
directly on the Sync columns button to
retrieve the schemma from the preceding component.
In the Query field, enter the SQL query
you want to use. Here, we want to retrieve the names of the American States
from the LabelState column of the MySQL table,
us_state:

"SELECT LabelState FROM us_state WHERE idState=?"

1
2

"SELECT LabelState
FROM us_state WHERE idState=?"

The question mark, “?“, represents the parameter to be set in
the Advanced settings tab.

Configuring the Advanced settings of tAmazonMysqlRow

Click Advanced settings to set the
component’s advanced properties.
Select the Propagate QUERY’s recordset
check box and select the LabelStateRecordSet column
from the use column list to insert the
query results in that column.
Select the Use PreparedStatement check
box and define the parameter used in the query in the Set PreparedStatement Parameters table. Click on the
[+] button to add a parameter.
In the Parameter Index cell, enter the
parameter position in the SQL instruction. Enter “1” as
we are only using one parameter in this example.
In the Parameter Type cell, enter the
type of parameter. Here, the parameter is a whole number, hence, select
Int from the list.
In the Parameter Value cell, enter the
parameter value. Here, we want to retrieve the name of the State based on
the State ID for every client in the input file. Hence, enter
“row1.idState".

Configuring the tParseRecordSet component

Double-click tParseRecordSet to set its
properties in the Basic settings tab of the
Component view.
From the Prev. Comp. Column list, select
the preceding components column for analysis. In this example, select
LabelStateRecordSet.
Click on the Sync columns button to
retrieve the schema from the preceding component. The Attribute table is automatically completed with the schema
columns.
In the Attribute table, in the Value field which corresponds to the
LabelStateRecordSet, enter the name of the column
containing the State names to be retrieved and matched with each client,
within double quotation marks. In this example, enter
“LabelState“.

Configuring the output component

Double-click tFileOutputDelimited to set
its properties in the Basic settings tab of
the Component view.
In the File Name field, enter the access
path and name of the output file. Click Sync
columns to retrieve the schema from the preceding component.

Job execution

Save your Job and press F6 to run it.

A column containing the name of the American State corrresponding to each client
is added to the file.

Related scenarios

For a related scenario, see:

Scenario 3: Combining two flows for selective output

Document get from Talend https://help.talend.com

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Docs 5.x

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tAmazonMysqlRow – Docs for ESB 5.x