Expression Builder

Expression Builder helps you to enter and validate SQL expressions, such as constraints for filters. An expression is a SQL statement or clause that transforms data or specifies a restriction. Expression Builder displays the available columns, provides a selection of functions and commonly used operators, and validates expressions.

To build and validate expressions in Expression Builder:

  1. Click edit in the Add Custom Transform dialog box. The Expression Builder dialog box opens.

  2. The Expression Builder dialog box has the following components:

    • Attributes tab: Lists attributes (columns) in the source data. To insert an attribute into the query that you are creating in the Expression box, or to replace characters that you selected, double-click the attribute at the current character position.

    • Functions tab: Lists the commonly used SQL Functions, divided into folders. Double-click a folder to view the functions listed there. To insert a function into the expression at the current character position or to replace characters that you selected, double-click the function.

    • Expression box: The expression that you create is displayed in the Expression box. You can create an expression in any one of the following ways:

      • Type the expression in the Expression box directly.

      • Add Attributes and Functions by double-clicking them in the Attributes tab and the Functions tab respectively.

      To add an operator into the expression, click the operator.

    • Commonly used operators are listed in below the Expression box. Click the appropriate operator, indicated by its symbols. If you prefer, you can enter an operator directly into the Expression box. Table: Commonly Used Operators lists the operators that you can enter:

      Commonly Used Operators

      To Enter this Operator Click

      Less than

      <

      Greater than

      >

      Less than or equal to

      ... for the symbol <=

      Greater than or equal to

      ... for the symbol >=

      Not equal to

      !=

      Equal to

      =

      Or (Logical Or)

      ...

      And

      ...

      Left parenthesis

      (

      Right parenthesis

      )

      Parallel symbol

      ||

      Add

      +

      Minus

      -

      Multiply

      *

      Divide

      /

      Percent

      %

    • Validation Results text area (read-only): Displays the validation results.

    • Validate: Click Validate to validate the expression in the Expression box. The results appear in Validation Results.

  3. When you have finished creating the expression, click OK.