sql - Different approach of using IN clause in MySql -

today have posted answer query this

select * table_name column_name in (val1,val2,...) 

some user has posted answer query this

select * table_name val1 in (column_name) 

as can see here position of column_name , values interchanged.

from mysql docs

expr in (value,...)

returns 1 if expr equal of values in in list, else returns 0. if values constants, evaluated according type of expr , sorted. search item done using binary search. means in quick if in value list consists entirely of constants.

mysql> select 2 in (0,3,5,7); -> 0  mysql> select 'wefwf' in ('wee','wefwf','weg'); -> 1 

as says above one(my query) correct. both above queries produce same output.

also why not other approach in listed in mysql documentation?

_{this question serves canonical information source regarding use of in. purpose have detailed, high quality answers detailing proper use on in in queries.}

you raised question connected answer here.

in simple explanation using statements below,

select * tablename column1 in (1, 2, 3, 4) -- versus select * tablename 1 in (column1, column2, column3, column4) 

the first statement involves one column being compared multiple values.

select  *   tablename  column1 = 1 or        column1 = 2 or        column1 = 3 or        column1 = 4 

while second statement a value compared multiple columns.

select  *   tablename  column1 = 1 or        column2 = 1 or        column3 = 1 or        column4 = 1 

which bit different 1 another.

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update 1

here's third form of in clause:

• multi-column in clause – unexpected mysql issue