c# - While databinding checkboxlist -

i have 2 checkbox lists in asp.net,

1st list has fruit names , 2nd list has few fruit names.

list getting populated database using sqldatasource

now need 1st list fruits should have fruits not in list 2

here's code sir,

private void allfruitsnames() {     using (sqldatasource ds = new sqldatasource(connectionstring(), "select fruitname fruittable"))     {             checkboxlist1.datasource = ds;             checkboxlist1.datatextfield = "fruitname";             checkboxlist1.databind();     } }  private void populateonlyfewfruitsnames(int crateid) {     checkboxlist2.items.clear();      using (sqldatasource ds = new sqldatasource(cs(), "select fruitname fruittable crateid ='" + crateid + "'"))     {             checkboxlist2.datasource = ds;             checkboxlist2.datatextfield = "fruitname";             checkboxlist2.databind();     } } 

how can balance fruits if fruit in 2nd checkbox list should removed checkboxlist 1

it appears have ids of fruits want in 2nd list.

just exclude fruits ids first query:

"select fruitname fruittable crateid not in(" + string.joing(",",crateidlist) + ")" 

btw: should not build sql queries way. vulnerable sql injection. use parameterized queries instead. here article on topic: using parameterized queries sqldatasource