Hp Integrity NonStop J-Series Manuel d'utilisateur télécharger pdf (Page 59)

100

101

DEVELOPING A DATA BASE

Listing the Fields in Each File

DependentsEmployee

ManyOne

Figure 3-7. One-to-Many Relationship

Listing the Fields in Each File

At this point, you have identified the two files in the personnel

data base: employee and dependents. Since dependents is too

long to be a valid file name (eight character maximum length),

you might shorten this name to "depend." The next step is to

list the fields in each file as shown in Figure 3-8.

-----------------------------------------------------------------

| |

| EMPLOYEE empnum, empname, regnum, branchnum, job, age, |

| salary, vacation |

| |

| DEPEND emp-no, dependent-name, relationship, dependent-age |

| |

-----------------------------------------------------------------

Figure 3-8. List of Fields in Both Files

Notice that both files contain a field that represents an

employee identification number. The presence of such duplicate

fields is essential because you need these fields to provide

logical connections when you use ENABLE to generate an

application or use ENFORM to request a report.

After you list the fields in each file, you are ready to select

the physical structure for the file.

3-8

1 2 ... 54 55 56 57 58 59 60 61 62 63 64 ... 361 362

Commentaires sur ces manuels

Pas de commentaire

Hp Integrity NonStop J-Series Manuel d'utilisateur Page 59

Commentaires sur ces manuels

Produits connexes et manuels pour Matériel informatique Hp Integrity NonStop J-Series