I have created CHECK constraint but receiving error message - sql

Question

create sequence student_studentid_seq
increment by 10
start with 100
nocycle;
create table student
(studentid number(10),
name varchar2(30) not null,
ss# number(9) unique,
gpa number(2,3) not null,
constraint student_studentid_pk PRIMARY KEY (studentid),
constraint student_gpa_ck CHECK (GPA >= 0) );
insert into student (studentid, name, ss#, gpa)
values(student_studentid_seq.NEXTVAL,'Draze Katan', 323456789,1);
receiving error message:
Error starting at line 29 in command:
insert into student (studentid, name, ss#, gpa)
values(student_studentid_seq.NEXTVAL,'Draze Katan', 323456789,1)
Error report:
SQL Error: ORA-01438: value larger than specified precision allowed for this column
01438. 00000 - "value larger than specified precision allowed for this column"
*Cause: When inserting or updating records, a numeric value was entered
that exceeded the precision defined for the column.
*Action: Enter a value that complies with the numeric column's precision,
or use the MODIFY option with the ALTER TABLE command to expand
the precision.
So it appears error message is for next constraint:constraint student_gpa_ck CHECK (GPA >= 0) );
In insert statement if I enter '0' for GPA raw will be inserted but anything more I will receive error message.
This is one of my exercise questions, I can't figure out. I just need hint where mistake is not full resolution. Please if you could help me out.

Answer 1

The issue is in the way you create the table, in particular in the column GPA.
You are using number(2, 3), which looks like "build a number with 2 total digits and 3 decimal digits".
In oracle documentation you find a better explanation about the NUMBER data type, its attributes and what things like number(2,3) mean:
Specify a fixed-point number using the following form:
NUMBER(p,s) where:
p is the precision, or the maximum number of significant decimal
digits, where the most significant digit is the left-most nonzero
digit, and the least significant digit is the right-most known digit.
Oracle guarantees the portability of numbers with precision of up to
20 base-100 digits, which is equivalent to 39 or 40 decimal digits
depending on the position of the decimal point.
s is the scale, or the number of digits from the decimal point to the
least significant digit. The scale can range from -84 to 127.
Positive scale is the number of significant digits to the right of the
decimal point to and including the least significant digit.
Negative scale is the number of significant digits to the left of the
decimal point, to but not including the least significant digit. For
negative scale the least significant digit is on the left side of the
decimal point, because the actual data is rounded to the specified
number of places to the left of the decimal point. For example, a
specification of (10,-2) means to round to hundreds.
Scale can be greater than precision, most commonly when e notation is
used. When scale is greater than precision, the precision specifies
the maximum number of significant digits to the right of the decimal
point. For example, a column defined as NUMBER(4,5) requires a zero
for the first digit after the decimal point and rounds all values past
the fifth digit after the decimal point.
For example:
SQL> create table tabError( a number (2, 3));
Table created.
SQL> insert into tabError values (1);
insert into tabError values (1)
*
ERROR at line 1:
ORA-01438: value larger than specified precision allowed for this column
SQL> insert into tabError values (0.1);
insert into tabError values (0.1)
*
ERROR at line 1:
ORA-01438: value larger than specified precision allowed for this column
SQL> insert into tabError values (0.01);
1 row created.
If you need 2 digits for the integer part and 3 for decimals, you need number(5, 3) or, according to Mathguy's comment, if you need numbers with one integer digit and 2 decimals, you need number(3,2).