Deriving Views › Defining Views › Step 2: Specifying the Source Tables and Join Criteria

Step 2: Specifying the Source Tables and Join Criteria

The Table Definition screen is still displayed. This screen enables you to perform a table derivation. Specify the following derivation information:

Specify Source Table(s)

• Type job in the Table Name field under the Source Table #1 heading in the Table Derivation section of the screen. This indicates that the JOB table is your first source table.
• Type applicant in the Table Name field under the Source Table #2 heading. This indicates that the APPLICANT table is your second source table.

Specify Join Columns

• Move the cursor to the Column #1 field. Enter the name of the column in the first source table that is related to a column in the second source table. This is the column on which you are joining the two tables. In this example, the TITLE column in the JOB table is related to the POSITION APPLIED FOR column in the APPLICANT table. Type title in the Column #1 field.
• Type position applied for in the Column #2 field.

Notice the statement Where Column #1 EQ Column #2 on the line with the Column #2 field. This indicates that you are joining the JOB table with the APPLICANT table, where the value of the TITLE column in JOB is the same as the value of the POSITION APPLIED FOR column in APPLICANT.

Join Does not Require Equality

You may not always want to join tables on an equal condition. For example, you may want to join two tables when the value of one join column is greater than the value of the other join column. You can change the EQ operator to specify other join conditions, such as GT (greater than) or LT (less than).

                             Table Derivation
  Source Table #1
   Table Name.: job1
   Table Owner:

  Source Table #2
   Table Name.: applicant2
   Table Owner:

  Column #1: title3
  Column #2  position applied for              Where Column #1 EQ4Column #2

1. Type JOB for the first source table.
2. Type APPLICANT for the second source table.
3. Enter TITLE and POSITION APPLIED FOR as the join columns.
4. Accept the default join operator EQ.

Select Define Columns

You have just defined the source tables and join criteria. You are now ready to define the columns for the JOBS AND APPLICANTS view. Select the Define Columns function ([PF2]) from the activity selection menu.