by jbarham:

The exp/sql documentation mentions support for bool and float values, but the conversion
function used by Scan doesn't support bool or float destination values.  The patch below
adds support for bool, float32 and float64 output types.

jbarham@ubuntu:~/go/src/pkg/exp/sql$ hg diff 
diff -r 978acc122f2e src/pkg/exp/sql/convert.go
--- a/src/pkg/exp/sql/convert.go    Thu Sep 29 21:31:41 2011 -0700
+++ b/src/pkg/exp/sql/convert.go    Mon Oct 03 22:04:32 2011 +1100
@@ -66,6 +66,15 @@
    }
 
    switch dv.Kind() {
+   case reflect.Bool:
+       if s, ok := asString(src); ok {
+           tf, err := strconv.Atob(s)
+           if err != nil {
+               return fmt.Errorf("converting string %q to a %s: %v", s, dv.Kind(), err)
+           }
+           dv.SetBool(tf)
+           return nil
+       }
    case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
        if s, ok := asString(src); ok {
            i64, err := strconv.Atoi64(s)
@@ -90,6 +99,18 @@
            dv.SetUint(u64)
            return nil
        }
+   case reflect.Float32, reflect.Float64:
+       if s, ok := asString(src); ok {
+           f64, err := strconv.Atof64(s)
+           if err != nil {
+               return fmt.Errorf("converting string %q to a %s: %v", s, dv.Kind(), err)
+           }
+           if dv.OverflowFloat(f64) {
+               return fmt.Errorf("string %q overflows %s", s, dv.Kind())
+           }
+           dv.SetFloat(f64)
+           return nil
+       }
    }
 
    return fmt.Errorf("unsupported driver -> Scan pair: %T -> %T", src, dest)