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Using <> in MySQL

I have come across <> used in a statement conditions a few times. Example:

SELECT param, d.param
FROM panel p join object d on p.i开发者_如何学God=d.id 
WHERE param IS NOT NULL and param<>''

Let me confirm the statement above has not been tested, it mimics some of the statements that I have come across.

My question is, what is the meaning of the the diamond <> condition?


<> is like NOT .. = .. and !=. It means not equal.

MySQL comparison operators - not equal


its the opposite of "equal" so it is "not equal".

in C it is !=

so in your question it means param is not a empty string

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