tWaitForSqlData Standard properties

Wait at each iteration (in seconds)

Set the time interval in seconds between each check for the sql data.

Max. iterations (infinite if empty)

Number of checks for sql data before the Jobs times out.

Use an existing connection/Component List

A connection needs to be open to allow the loop to check for sql data on the defined DB.

When a Job contains the parent Job and the child Job, Component list presents only the connection components in the same Job level, so if you need to use an existing connection from the other level, you can

From the available database connection component in the level where the current component is, select the Use or register a shared DB connection check box. For more information about this check box, see tMysqlConnection for the connection components according to the database you are using.

Otherwise, still in the level of the current component, deactivate the connection components and use Dynamic settings of the component to specify the intended connection manually. In this case, make sure the connection name is unique and distinctive all over through the two Job levels. For more information about Dynamic settings, see Talend Studio User Guide.

Table to scan

Name of the table to be checked for insert or deletion

Trigger action when rowcount is

Select the condition to be met for the action to be carried out:

Equal to Not Equal to Greater than Lower than Greater or equal to Lower or equal to

Value

Define the value to take into account.

Then

Select the action to be carried out: either stop the iterations when the condition is met (exit loop) or continue the loop until the end of the max iteration number (continue loop).

Global Variables

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.

CURRENT_ITERATION: the sequence number of the current iteration. This is a Flow variable and it returns an integer.

ROW_COUNT: the number of rows detected in the table. This is a Flow variable and it returns an integer.

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

Although this component requires a Connection component to open the DB access, it plays also the role of the start (or trigger) component of the subJob which gets executed under the condition described. Therefore this component requires a subJob to be connected to via an Iterate link.