Search for text between delimiters in MySQL

Question

I am trying to extract a certain part of a column that is between delimiters.

e.g. find foo in the following

test \'esf :foo: bar

So in the above I\'d wa

Answer 1

mid(col, 
    locate('?m=',col) + char_length('?m='), 
    locate('&o=',col) - locate('?m=',col) - char_length('?m=') 
)

A bit compact form by replacing char_length(.) with the number 3

mid(col, locate('?m=',col) + 3, locate('&o=',col) - locate('?m=',col) - 3)

the patterns I have used are '?m=' and '&o'.