Specifying file selections for a Query for iSeries query

Chapter 4. Specifying and selecting files for a Query for iSeries query

This chapter describes how you select and use one or more database files that are to be queried for information. Specifying file selections (the first option on the Define the Query display) is the first of the 11 steps that you can use to define a query. This step includes specifying (or changing) what files you want to select for your query, seeing what files are already selected, and specifying the join characteristics when more than one file is selected. This step also allows you to select, when necessary, file members and record formats for the files.

Notes:

1.Although this chapter discusses this step primarily for the task of creating a query definition, most of the information also applies to the tasks of changing or displaying an existing definition.

2.If you are creating a query, a 1 is already supplied by the system for the Specify file selection option on the Define the Query display, and it cannot be removed. This is the only option in the definition process that you must select when you are creating a query.

3.If you make changes to any of the file selection values in this step, Query attempts to keep whatever parts of the definition that are still valid. For example, if a field in a file being removed from the definition also exists in a file being added (as a replacement), the field’s uses in other parts of the definition (such as part of the sort definition) are kept. (However, it is your responsibility to determine whether the field in the replacement file contains the kind of information you want.)

The displays related to the file selection process are:

vFile selection displays (for one or more files):

–Specify File Selections

–Select Library (optional)

–Select File (optional)

–Select Member (optional)

–Select Record Format (optional)

vFile join displays (for multiple files only):

–Specify Type of Join

–Specify How to Join Files