mysql: mysterious sideways single quote and IS NOT NULL -


i have 2 queries can run , 2 totally different results, solely because use "sideways single quote" versus single quote. see below:

select * items 'natural' not null

will return every record regardless if "natural" column set null

select * items `natural` not null

will correctly return records there values set column "natural"

that ain't right.

your first example 'natural' not null tests see if string literal 'natural' not null. since string literals not null, condition true.

the second example tests value of column name natural. want.

related

string literals

a string sequence of bytes or characters, enclosed within either single quote (') or double quote (") characters.

schema object names

the identifier quote character backtick ( ` )


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