Can a primary key have null values? If we try to insert a
null value in a primary key column, will it work or give an
error code?
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Answer / sangeetha
There cannot be null values in a Primary Key column.
It will result in error code.
| Is This Answer Correct ? | 26 Yes | 3 No |
In DB2 you can not create a primary key on a column which
is not 'not null'.
If you are trying to create a primary key on a column which
is not 'not null' then dbb2 will return an error like this
SQL0542N "feild_name" cannot be a column of a primary key
or unique key because it can contain null values.
SQLSTATE=42831
But once u alter the table and set the column to 'NOT NULL'
then you can make it as primary key.
Now if u r trying to insert an null value to ur primary key
column then db2 will trows an error like
SQL0407N Assignment of a NULL value to a NOT NULL
column "TBSPACEID=5, TABLEID=404, COLNO=0" is not allowed.
SQLSTATE=23502.
In short you can not make a column which can hold 'NULL'
value as your primary key and you can not insert a 'NULL'
value into your primary key feild.
Cheers,
Ratheesh Nellikal
| Is This Answer Correct ? | 7 Yes | 1 No |
Answer / satya prasad n
The PRIMARY KEY cannot be null. you can insert ZERO into
that but should not be null. It will throw an error if you
try to inserts a NULL.
| Is This Answer Correct ? | 8 Yes | 4 No |
Answer / guest
A primary key can have a NULL value. The error will be
shown only when NOT NULL is defined in the table creation.
| Is This Answer Correct ? | 10 Yes | 10 No |
Answer / sachin borase
May be it will throws the -803 error (803 means index
violation )
| Is This Answer Correct ? | 1 Yes | 4 No |
Answer / priya
Can you please clarify what kind of error code/sqlcode will
be returned if we try to insert a null value in a primary
key using a DB2 insert query?
| Is This Answer Correct ? | 2 Yes | 7 No |
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