SQL VARA Objects

SQL VARA objects retrieve values from external databases using SQL statements.

Prerequisites

To retrieve values from a database, you need:

• A DB Service Agent for variables that is individually configured and started.

  This Agent cannot be used to execute database jobs and events, see Installing the Agent for Database Variables.

• A database-type Connection object which contains the database connection parameters, see Connection (CONN)
• A Login object includes the database user and the password, see Login (LOGIN)

Defining SQL VARA Objects

An SQL VARA object definition is made up of the following pages:

• General Page

• Variables

  Here you define the object-specific settings. Some sections on this page are common to all VARA objects and are described for all of them in dedicated topics:

  • Variable Settings, see below
  • Parameters
  • Data Types and Formatting
  • Script Access
  • Client 0 VARA Objects in Other Clients
  • Preview, see below
• Version Management Page
• Documentation Page

Overview

There is no limit to the lengths of values. If a maximum text limit has been selected in the Attributes Page, this only applies to the first value column. Items exceeding this limit will be excluded.

Important Considerations

When using SQL VARA objects take the following into account:

• The maximum number of lines that is returned is specified in the SQLVAR_MAX_ROWS setting (UC_SYSTEM_SETTINGS - Systemwide Settings.

• To change the maximum time taken for resolving SQL variables, use VAR_TIMEOUT (UC_HOSTCHAR_*).

• Non-printable characters are deleted automatically (ASCII characters 0x00 to 0x20 and 0x7F).

• The Automation Engine does not truncate trailing space characters from the end SQL variable values.

• Database VARA objects (SEC_SQLI, SEC_SQL, SQLI, and SQL types) do not support binary fields. Binary data that result from an SQL query causes an error in the preview or when the values are retrieved at runtime.

• In database VARA objects (SEC_SQLI, SEC_SQL, SQLI, and SQL types), the system does not check the SQL statements that are processed for technical reasons. You can change or delete data records by using VARA objects. For security reasons, consider restricting user access accordingly. If possible, deploy a database user with read-only rights for VARA objects that can access an external database (SQL, SQL SECURE). For internal SQL variables (SQLI, SQLI SECURE), you can limit object access via a privilege (create and modify SQL-internal variables).

• Depending on the data type, database VARA objects (SEC_SQLI, SEC_SQL, SQLI, and SQL types) return the value "" (string, date, time, timestamp) or 0 (number) for NULL values.

• PromptSet variables are supported in select fields for BACKEND, EXEC, FILELIST, SEC_SQLI, SEC_SQL, SQLI, SQL, and XML variable types. Using PromptSet variables is necessary when using the Dynamic Reload (Combobox Prompts) feature.

Variable Settings Section

• Type

  Rad-only, always SQL.

• Connection

  The Connection object of type Database that contains the connection parameters for the selected database, see Connection (CONN).

• Login

  The Login object that stores the name and password of the database user, see Login (LOGIN).

  If you neither specify a Login object nor set the option Default login, the login data for accessing the database is retrieved from the Connection object.

  An error occurs if the VARA object is to be resolved and this object does not include any login information.

• Default Login

  You can also select a Login object for SQL VARA objects in the User object (default login), see Users (USER).

  Activate the Apply user's login option to apply the Login object that is assigned to the current user. As a result, the Login object that is specified in the VARA object is ignored.

  An error occurs if the VARA object is to be resolved and no login is defined in the User object.

  PromptSet variables cannot be used here.

• SQL Statement

  The SQL statements used to select specific database entries that serve as variable values.

  Variables that are directly specified in SQL will not be replaced. To include variables, use bind parameters.

  Maximum length: 4096 characters

You can include PromptSet variables here when using the Dynamic Reload (Combobox Prompts) feature for Combobox prompts. When you use PromptSet variables in a dynamic VARA object, the Preview feature returns an error. This is because the PromptSet variables do not exist in the dynamic VARA object. However, the PromptSet variables will be resolved when objects including the PromptSet are executed.

Preview section

To run a command, select it and click Preview. The statements are executed and their results displayed. The preview function serves to check for potential errors in the database statements (for example, it the data type of the VARA object and of the database do not match).

The database Agent sends the preview data to the Automation Engine in the form of a message. If this message exceeds the maximum message length that a server process accepts, an error occurs.

Maximum length: Set in the MaxMsgSize= parameter of the Automation Engine UCSRV.INI file. For more information, see Automation Engine.

Default value: 3145 728 bytes. You can limit the result either by using a maximum number of lines or through SQL statements.

See also:

• VARA Objects
• Variables and VARA Objects