The Table Fields Page: External Table

The Fields page is used to determine the structure of an external table, that is, a list of table fields and their properties are set.

NOTE. The Fields page is available only in the external table wizard in the web application.

To create a new field, click the Add button. A line is added to the end of the list, in which specify field properties:

Type/Data Type. Select data type in the drop-down list:

String.
Integer.
Real.
Date and time.

The string data type is selected by default.

Name. Enter a name that describes field value. The default name: Field <Number>.
Identifier. Determine a unique table field name to be used for SQL queries and to determine links between tables. Identifier can consist of only Latin letters, numbers and underline character. The default identifier: FIELD<Number>.
Total Length. Determine the maximum length of table field: this value represents the number of symbols for the symbol type or the number of digits for the numeric type.
Decimal Places. Determine the number of fractional decimal places for numeric fields.
Empty Values. Select the checkbox to determine whether a field can store empty values.
Default Value. Determine the value that goes automatically into every new created table field. For example, one can enter the most frequently occurring value.
Value/Calculated Field. Use the drop-down list to determine whether a field is calculated. When a calculated field is set, a confirmation dialog box opens warning the user about deleting all field data. After the operation is confirmed, set a formula, which will calculate field value. To do this, click the Insert into Formula button. The expression editor window opens.

To change the number of displayed properties, select or deselect checkboxes next to property names in the drop-down menu of the Settings button.

Expression Editor

Formulas can be set up in the expression editor. The expression editor window for setting up calculated fields of external table looks as follows:

Operands, arithmetic operations, functions, numbers, comparison characters and round brackets can be used in a formula. There are some features of use:

All element types, except for numbers, can be inserted both using the keyboard or special panels.
Numbers are inserted only using the keyboard.

Operands are displayed on the expression editor's operands panel:

Other table fields are used as operands.

To insert an operand to the formula area, execute one of the operations:

Using the operands panel:

Select the operand and click the Insert into Formula button.
Double-click the operand.
Drag the operand to the formula area.

Using the formula area:

Enter the operand name in the formula area.
Click in the formula area in the place where the operand should be put, press CTRL+SHIFT and select the required operand on the pop-up panel.

To quickly search for an operand, start typing partial or full name of the operand in the search string. After executing the operation the operands panel displays the operands, which names satisfy search conditions.

To set up displaying of the operands list, use items in the drop-down menu of the Display Settings button:

Name. Default value. Only operand names are displayed.
Identifier. Only operand identifiers are displayed.
Name and Identifier. Operand names and identifiers are displayed in the format: <name> (<identifier>).

To hide the operands panel, click the Hide Operands Panel button. To show the panel, click the Show Operands Panel button.

Inserting Functions and Operators