i Series Database Files Physical Files Logical Files

i. Series Database Files • Physical Files • Logical Files *FILE PF-DTA LF

Physical Files • It is an as/400 file used to store data or source code. • Physical files have members. • The members contain data or source code. • Source physical files have many members eg. One for each program • Data physical files usually have 1 member (but can have more)

Data Files, Records, Fields • A file member contains one or more records • A record is made up of one or more fields which give it its record format or file description • Each field contains a unique piece of information e. g. student no, first name, last name, address, telephone no, etc.

Examples of Files, Records, Fields • A customer file is made up of customer records (1 per customer). • Each customer record has fields containing unique pieces of info about a particular customer e. g. customer name, address, sales territory, billing info, shipping instructions, credit information • Student file - student records (1 per student)- student info: name, address. . .

More Examples of Files, Records, Fields • Parts file - parts records - info about part: part number, description, warehouse location, supplier, quantity on hand, • Payroll file - payroll records - payroll info for employees: employee number, name, date of hire, hourly or salary, hourly rate or annual salary, income tax info….

How do we create data physical files?

Creating Physical Data Files • Creating an AS/400 data file is very similar to creating a program: – Write the source code (the source code will describe what the file will look like). The source code is stored in a member in a source file. – Compile the source code (this creates a *file object).

Tools for Describing Database Files • Data Description Specifications (DDS) – AS/400 language to create source code for Files • Others: – SQL (Structured Query Language), (you will do this in DB 2 course)

Using DDS • Source code is entered into a source physical file member in the form of DDS statements. This is done using the i. Series editor SEU • The DDS statements describe each field of the record in detail e. g. field name, data type (numeric, character, packed numeric, etc), standard column headings, etc. • The source file for DDS is QDDSSRC.

Example of DDS Columns. . . : 1 71 Browse DMENKEN/QDDSSRC SEU==> STUPF FMT PF. . . A. . T. Name++++++ RLen++TDp. B. . . Functions+++++++++ ******** Beginning of data ******************* 0001. 00 0002. 00 A R STUPFR 0003. 00 A SOCINS 9 S 0 COLHDG('Social' 'Insurance' 0004. 00 A FNAME 15 A COLHDG('First' 'Name') 0005. 00 A LNAME 20 A COLHDG('Last' 'Name') 0006. 00 PHONE 10 S COLHDG('Phone' 'No. ') 0007. 00 A ADDR 1 25 A COLHDG('Street' 'Address') 0008. 00 A ADDR 2 25 A COLHDG('City') 0009. 00 A ZIP 5 S 0 COLHDG('Zip Code') ********* End of data ********************

Creating a Database File • Create the source file (CRTSRCPF) which is named QDDSSRC (only done once) • Create a source member, type PF • Enter the source code using SEU • Save source code and compile to create the file • Put data into the file.

• The source type: – tells SEU what type of source you are creating e. g. TXT, PF, LF, etc. Used for prompting and checking the syntax – will tell PDM which compiler to use when creating the object.

Entering DDS code • First statement is the Record Format statement. Put an R in the Name Type field and the record name in the Name field. • Then enter the field info (field name, length, data type, decimal positions, standard column heading) (nothing in Name Type field)

Demo

Compiling the Source Code • CRTPF command or Option 14 in PDM takes the source code and creates the object i. e. the physical file is what holds the data

How do you know if the compile worked? ? ? • DSPMSG- you will have a message which tells you whether your job completed normally or not. • An output file is created with each compile (the compile listing) which tells you what happened. READ it! • Where is that output file? ? – In your output queue!!

Question! • If the compile ended abnormally, what do you do? How can you find out why?

Unique feature of i. Series Files • The record description is stored with the file object (externally described file) • It can then be used by i. Series utilities • The record description does not have to be coded in programs that use it. • Can be viewed using DSPFD, DSPFFD

Entering data • If the compile was successful, you will have a new object in your library, a physical file. • To enter data into that file, use DFU, Data File Utility

DFU • STRDFU, then option 5 • PDM option 18 or… • F 10 to enter new records (entry mode) • F 11 to change records (change mode), page up and down to find records • F 23 to delete a record

Viewing records • RUNQRY QRYFILE(filename) • DSPPFM filename