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One of the functions of the Librarian is to maintain a resume database
for Personnel, for potentially qualified staff for jobs as they open
up. Therefore one of the tables in the Acme Online Corporate Library
System is the RESUME Table. This table is created by issuing the
CREATE TABLE command.
If you enter the following:
CREATE TABLE RESUME
( RES_ID CHAR(5),
RNAME CHAR(15),
JOB CHAR(15),
EDUC CHAR(60),
EXP VARCHAR(2000)
);
SQL statements as passed to TEXIS can be entered on one or more lines.
Indenting is recommended to improve readability, but it is not
required.
The CREATE TABLE command is entered interactively at a
terminal, or as embedded in an application program. Note that the
list of column definitions is enclosed in parentheses and that each
column definition is separated from the next column definition by a
comma. In all examples in this text, each SQL statement is shown in
uppercase letters to help you identify what is to be entered.
However, in most cases you actually can enter the statement in either
upper or lowercase.
The first line in the CREATE TABLE statement identifies the name of
the table: RESUME. The next five lines define the five columns that
make up the RESUME table. The data types chosen to define each column
are explained further on in this chapter.
- The first column, named RES_ID, stores the resume's
identification number (ID).
Five characters are allowed for a Resume ID,
following Acme internal naming conventions of a letter followed by up
to 4 other characters; e.g., `
R243' or `R-376'. - The second column, named RNAME, stores the name of the resume's
job applicant. No name longer than 15 characters can be stored in
this column.
- The third column, named JOB, stores the job or jobs the person
is applying for. A maximum of 15 characters is allowed for this
column.
- The fourth column, named EDUC, stores a brief description of the
applicant's education. A maximum of 60 characters is allowed for this
column. Note: One could choose to define EDUC with VARCHAR rather
than CHAR, so that a full educational description could be entered
without regard to waste of allocated space.
- The fifth column, named EXP, stores the full text description of
the applicant's job experience as included in the resume. You have
two choices for the text field:
- You can store the entire description in the TEXIS table. This
is useful for short descriptive lines, for abstracts of one or more
paragraphs, or for short reports of one to two pages as depicts the
usual resume. Data type would be defined as a variable length
character VARCHAR(x) where X indicates the suggested number of
characters.
- You can store filenames in the TEXIS table. In this case TEXIS
would use the filename to direct it to the text of the actual file.
Data type would be defined as INDIRECT.
In our EXP text column for the RESUME table we have chosen to store
the full text in the TEXIS table, as concept searches of this column
are part of almost every resume search request. If we only
occasionally referred to the full text content, we might prefer to
store filenames which would point to the full text only when
necessary.
Tables defined with the CREATE TABLE command are referred to as
base tables. The table definition is automatically stored in a data
dictionary referred to as the system catalog. This catalog is
made up of various tables that store descriptive and statistical
information related to the database. The catalog can be accessed to
retrieve information about the contents and structure of the database.
The system catalog is discussed in more detail in
Chapter here.
As shown in Figure here, the CREATE TABLE command results
in an empty table.
RES_ID RNAME JOB EDUC EXP
(No data is stored in the table at the time it is created.)
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Figure: RESUME Table after the CREATE TABLE Command
Copyright © Thunderstone Software Last updated: Sun Mar 17 21:14:49 EDT 2013
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