Basic Screens › Data Selection Screen—DSEL

Data Selection Screen—DSEL

Description

The Data Selection screen is used to select rows from a table for display through the ASF-generated application.

Access

The Data Selection screen can be accessed for any table with a status of GENERATED. You can access the Data Selection screen in the following ways:

• Select the Select Data function from the Activity Selection screen; you can select the function by pressing [PF5].
• Enter DSEL in the screen name field of any screen.

To display selected rows, enter selection criteria and press [Enter]. When ASF saves the criteria you have specified, press [Enter] again to access the Data Display screen, which displays the selected rows.

Sample Screen

                                                      CA
  DSEL   CA - Automatic System Facility            ** Data Selection **
  DC560603 ENTER SELECTION CRITERIA
  Table Name: APPLICANT
               _ PF1 - Help      _ PF2 - Message Screen          Page:  1  of  1

   ID           Column Name                      Selection Criteria
  0001 NAME
  0002 STREET
  0003 CITY
  0004 STATE
  0005 ZIP CODE
  0006 PHONE NUMBER
  0007 POSITION APPLIED FOR
  0008 SALARY REQUIREMENT
  0009 EVALUATION: STRONG,WEAK,MEDIUM





                          Additional Selection Criteria
$5 OR $6 OR #6 MATCHES '617'

Fields

Table Name

Displays the name of the table as specified on the Activity Selection screen.

[PF1] - Help

Invokes the Help screen.

[PF2] - Message Screen

Invokes the display of additional error messages on a separate screen. The message display line will tell you when there are error messages to be displayed.

Page: ___ of ___

Displays the current screen page number and the total number of pages in the page set. You can move to a particular page by specifying its page number, page forward using [PF8], or page backward using [PF7].

ID

Displays the column ID number that can be used to reference the column in selection criteria or in calculations defined on the Extended Column Definition screen.

Column Name

Displays the name of each column defined for the table.

Selection Criteria

Enter fixed-format expressions to select rows based on column values. Fixed-format expressions are explained below. Enter the expression next to the name of the appropriate column(s). If you enter selection criteria for more than one column, you are indicating that only those rows that meet all criteria for all columns are to be displayed.

Additional Selection Criteria

Enter freeform expressions to select rows based on compound conditions. Freeform expressions can include compound conditions using the logical operators AND, OR, NOT, &, |, and ¬. You can use parentheses to affect the order in which logical operators are evaluated. Freeform expressions can be used in addition to, or instead of, fixed-format expressions to specify selection criteria. When used in conjunction with fixed-format expressions, freeform expressions can be used to override the implied AND connecting fixed-format expressions. Freeform expressions are discussed below.

Special Considerations

To select rows for display, specify selection conditions in the Selection Criteria and/or the Additional Selection Criteria fields. The Selection Criteria field accepts fixed-format expressions; the Additional Selection Criteria field accepts freeform expressions:

• Fixed-format expressions allow you to define selection criteria on a column-by-column basis, using simple logical expressions (including arithmetic expressions) that contain a single operator (such as EQ, GT, or MATCHES). With fixed-format expressions, you can define criteria for more than one column. The system then selects rows where all expressions are true (that is, using an implied AND as a conjunction between each fixed-format expression). :tref refid=ffsel. illustrates the format of fixed-format expressions used to specify selection criteria.
• Freeform expressions allow you to define selection criteria using compound logical expressions (including arithmetic expressions) that contain several operators connected with AND and OR. Freeform expressions also enable you to specify criteria using NOT. Freeform expressions can be used in addition to, or instead of, fixed-format expressions.

The following rules govern all selection criteria, both fixed-format and freeform:

• To specify an alphanumeric string, enclose the string in quotation marks. If the string contains a quotation mark, double the embedded quotation mark; for example, 'O' 'BRIEN'.
• To specify a column name containing special characters (including hyphens, spaces, and periods), enclose the column name in parentheses following the literal COLUMN, which can be abbreviated to COL; for example, COL(LATE PAYMENT COUNT).
• To evaluate a column entry character by character, use a mask to specify the exact or generic character to appear in each position. Use the following mask characters to specify generic characters:
  • * to represent any character
  • @ to represent any alphabetic character
  • # to represent any numeric character

  A string containing mask characters can be used with the operators CONTAINS and MATCHES and must be enclosed in quotation marks. Column positions not included in the mask are assumed to contain any character.

• To refer to a column by column ID number, precede the column ID number by # (pound sign); for example, #4.
• To select column entries based on a computed value, enter an arithmetic expression after the conditional operator. Arithmetic expressions can include:
  • Numeric values
  • References to one or more columns in the table, including the column for which the calculation is being defined. References can be designated as follows:
    • By entering the column name
    • If the column name includes special characters, by entering COL(column-name)
    • By entering the ID assigned to the column on the Extended Selection Definition screen, preceded by a pound sign: #column-id
  • Arithmetic operators:

• Parentheses to separate operations or alter the order of evaluation

ASF follows the standard order of precedence when evaluating arithmetic expressions. The order is multiplication and division from left to right, then addition and subtraction from left to right, with operations in parentheses resolved first. If more than one arithmetic expression has been defined in the selection criteria, they are evaluated in the order in which the columns were defined.

• To specify a range of values in a fixed-format expression, use the keyword THRU to separate the first and last values in the range.
• To specify a list of values in a fixed-format expression, separate each value in the list by a comma, which acts as an implied OR.
• To refer to a fixed-format expression in a freeform expression, precede the column ID number by $ (dollar sign); for example, $4.

Fixed format selection criteria:

*Expression can be any of the following:

• Quoted string
• Quoted string including mask characters (valid for CONTAINS and MATCHES only)
• Decimal number with optional sign
• Name of another column in the table
• Column ID number in the form #column-id
• Arithmetic expression

Note: Only the EQ(=) and NE operators can be used with a range (represented by THRU) or with a list of values joined by implied ORs (represented by commas).

Freeform selection criteria:

*NOT is optional

Using $column-id as the comparison allows you to override the implied AND invoked when multiple fixed-format expressions are specified. For example, if you have specified fixed-format criteria for columns #1, #3, and #6, using fixed-format criteria alone implies that all three conditions must be true for a row to be selected. By using freeform selection criteria, you can specify $1 OR $3 as additional criteria. Then, the condition for column #1 or column #3 and the condition for column #6 must be true for the row to be selected.

Valid comparisons for freeform selection criteria:

*Expression can be any of the following:

• Quoted string
• Quoted string including mask characters (valid for CONTAINS and MATCHES only)
• Decimal number with optional sign
• Name of another column in the table
• Column ID number in the form #column-id
• Arithmetic expression

The following examples illustrate the use of fixed-format and freeform expressions to specify selection criteria.