something about"like"

 hi,guys:
Now i am in this situation:I want to use the cause "like",i wrote:
string commd = "select * from buyerinfo where BuyerName like '%?blurName%'";
MySqlParameter para = new MySqlParameter("?blurName", MySqlDbType.VarChar, 45, "BuyerName");
para.Value = blurName;
It didn't work.
I changed that like this:
string commd = "select * from buyerinfo where BuyerName like '%"+"?blurName"+"%'";
MySqlParameter para = new MySqlParameter("?blurName", MySqlDbType.VarChar, 45, "BuyerName");
para.Value = blurName;
 or:
blurName="'%"+"blurName"+"%'";
string commd = "select * from buyerinfo where BuyerName like ?blurName";
MySqlParameter para = new MySqlParameter("?blurName", MySqlDbType.VarChar, 45, "BuyerName");
para.Value = blurName;
It also didn't work, when executed ,It returned nothing ,which definitely wrong.
Any advise would be appreciated,thx!
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Best regards！
haitao