Retrieve the data using LIKE % (SQL query) in C#

Hi Team,

Retrieve the data from database into datagridview using SQL query (Like %) in C# 2008. while I perform the below coding in C# it's not work. Below is my coding.

SQLconnection con=new SQLconnection();
SQLCommand cmd=new SQLCommand();
SQLDataadapter adp=new SQLDataadapter();

con=new sqlconnection(" .........connection string here ..........");
con.open();

adp=new sqldataadapter(" select customername from customers where customername LIKE % (' "+ textbox1.text+" ')",con);

ds=new dataset();

adp.fill(ds);

datagridview1.datasource=ds.datatable[0];

con.close();

It's not work. What is a wrong here? Please help me.