How can i assign an select statement into a variable?

Shell Programming and Scripting
1

I am trying to assign an select statement into a variable. Can someone hel me with this.

example :
a='select * from dual'
 
echo $a should give me select * from dual

But this is not working. I trying with \ before * and quotes too.

2

Quote the variable:

a='select * from dual'
 
echo "$a"