Using null in mysql

JPro JPro 5, 12 12 gold badges 55 55 silver badges 81 81 bronze badges. Add a comment. Active Oldest Votes. Also foreign keys depend on a NULL value to signify there is no related record.

Andy Shellam Andy Shellam Aiden Bell Aiden Bell I might use NULL while others put descriptions in another table. Daniel Vassallo Daniel Vassallo k 70 70 gold badges silver badges bronze badges. Sign up or log in Sign up using Google. Sign up using Facebook.

Sign up using Email and Password. Post as a guest Name. Email Required, but never shown. The Overflow Blog. There will be cases when we will have to perform computations on a query result set and return the values. Performing any arithmetic operations on columns that have the NULL value returns null results. In order to avoid such situations from happening, we can employ the use of the NOT NULL clause to limit the results on which our data operates.

The employee number should always be supplied. The basic syntax when null is used as a keyword is as follows. Continuing with the example above , suppose we need details of members whose contact number is not null. We can execute a query like.

Skip to content. Emerion Emerion 6 6 silver badges 13 13 bronze badges. Mahadi Hasan Mahadi Hasan 1 1 1 bronze badge. Petter Friberg Srikanth Kattam Srikanth Kattam 1. Welcome to SO, Please explain your answer code only answers are not very useful in many cases. What makes you think that simply dumping a query helps? How does that query answer the given problem? Sign up or log in Sign up using Google.

Sign up using Facebook. Sign up using Email and Password. Post as a guest Name. Email Required, but never shown. The Overflow Blog.