tMysqlInput Standard properties

Select a type of database from the list and click Apply.

Property type

Either Built-In or Repository.

Built-In: No property data stored centrally.

Repository: Select the repository file where the properties are stored.

Click this icon to open a database connection wizard and store the database connection parameters you set in the component Basic settings view.

For more information about setting up and storing database connection parameters, see Talend Studio User Guide.

DB version

Select the version of the database to be used.

Use an existing connection

Select this check box and in the Component List drop-down list, select the desired connection component to reuse the connection details you already defined.

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. It defines the number of fields (columns) to be processed and passed on to the next component. When you create a Spark Job, avoid the reserved word line when naming the fields.

This component offers the advantage of the dynamic schema feature. This allows you to retrieve unknown columns from source files or to copy batches of columns from a source without mapping each column individually. For further information about dynamic schemas, see Talend Studio User Guide.

This dynamic schema feature is designed for the purpose of retrieving unknown columns of a table and is recommended to be used for this purpose only; it is not recommended for the use of creating tables.

Built-In: You create and store the schema locally for this component only.

Repository: You have already created the schema and stored it in the Repository. You can reuse it in various projects and Job designs.

Click Edit schema to make changes to the schema. If the current schema is of the Repository type, three options are available:

• View schema: choose this option to view the schema only.

• Change to built-in property: choose this option to change the schema to Built-in for local changes.

• Update repository connection: choose this option to change the schema stored in the repository and decide whether to propagate the changes to all the Jobs upon completion. If you just want to propagate the changes to the current Job, you can select No upon completion and choose this schema metadata again in the Repository Content window.

Table Name

Name of the table to be read.

Query type and Query

Enter your DB query paying particularly attention to properly sequence the fields in order to match the schema definition.

If using the dynamic schema feature, the SELECT query must include the * wildcard, to retrieve all of the columns from the table selected.

Select this check box and specify the alias of a data source created on the Talend Runtime side to use the shared connection pool defined in the data source configuration. This option works only when you deploy and run your Job in Talend Runtime .

This check box is not available when the Use an existing connection check box is selected.

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.

Enable stream

Select this check box to enables streaming over buffering which allows the code to read from a large table without consuming a large amount of memory in order to optimize the performance.

This check box is available only when Mysql 4 or Mysql 5 is selected from the DB Version drop-down list.

Trim all the String/Char columns

Select this check box to remove leading and trailing whitespace from all the String/Char columns.

Trim column

Remove leading and trailing whitespace from defined columns.

tStatCatcher Statistics

Select this check box to collect log data at the component level.

Global Variables 

NB_LINE: the number of rows processed. This is an After variable and it returns an integer.

QUERY: the 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 rule

This component covers all possible SQL queries for Mysql databases.

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 examples on using dynamic parameters, see Reading data from databases through context-based dynamic connections and Reading data from different MySQL databases using dynamically loaded connection parameters. For more information on Dynamic settings and context variables, see Talend Studio User Guide.