NOT NULL indicates that the column cannot have a NULL value for any record; NULL indicates that NULL is a valid value (even when the column has a foreign key constraint).
NULL is defined as "a missing unknown value," and it is treated differently than other values. Because the result of any arithmetic comparison with NULL is also NULL, such comparisons yield no meaningful results. In MySQL, false is 0 or NULL, and true is anything else.
NOT NULL indicates that the column cannot have a NULL value for any record; NULL indicates that NULL is a valid value (even when the column has a foreign key constraint).
In MySQL, you use the ALTER TABLE MODIFY command to remove a NOT NULL constraint for a column and then restate the column definition, eliminating the NOT NULL attribute.
NULL is defined as "a missing unknown value," and it is treated differently than other values. Because the result of any arithmetic comparison with NULL is also NULL, such comparisons yield no meaningful results. In MySQL, false is 0 or NULL, and true is anything else.
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vj tricks
5
This course is very good
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Sanjeev Rana
5
Please provide course notes
A
Ankit Patel
5
Thank you learnvern and learnvern is best platfrom a lern a new skill. again thank you.
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Yadav Aakash
5
learnvern doing greate job...Thank you teacher's content team.
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Utkarsh Chimote
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Awesome really great teaching and this is good platform for we are poor peoples😍🤗
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parth joshi
5
Awasome really great ......but kindly resolve your payment error as soon as possible pls
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