Selection criteria define the subset of related data to extract from the list of tables in the Access Definition. You can define explicit selection criteria in the Access Definition, or create variables with default values that can be overridden by values specified on the Variables tab in the Extract Request Editor. You can also choose to be prompted for values at runtime.
The flexibility provided by using variables allows you to use the same Access Definition for different processes.
Information for each variable in the Access Definition is presented in three parts on the grid. The variable name is shown in the left column. The grid cell in the right column is divided in two. The prompt string for the variable displays in the top half of the cell and the value used as criteria displays in the bottom.
Assigned values must be the appropriate data type and size for the column and must conform to the SQL syntax. For example, assume a variable named ST is assigned to a character column containing state abbreviations. The variable delimiter is a colon. If the variable is defined with single quotes in the Access Definition, you must specify the value without single quotes on the Variables tab:
Access Definition | Value |
---|---|
':ST' | CA |
If the variable is defined without single quotes in the Access Definition, you must specify the value with single quotes on the Variables tab:
Access Definition | Value |
---|---|
:ST | 'CA' |
Select the Always Prompt for Values at Run Time check box to display the prompt string before each Extract Process is performed, regardless of whether a value has been assigned. Clear the check box to display the prompt string only when a value for a variable has not been assigned.