Question

Let’s say I have a table with 3 columns: C1, C2, C3

I make a search based on the C1 column.
Could I make something similar like this (this is not working – because this is not the way prepareStatement it’s used🙂 )

String c;// the name of the column

...    
String sql = "select * from table where ?  = ?";
                pre = con.prepareStatement(sql);
                pre.setString(1, c);
                pre.setString(1, i);
                rs = pre.executeQuery();

The main idea, I don’t want to have 3 ifs for every column. An elegant solution?

Answer 1

you could code up a a set of sql queries and store them in a map, then grab one based on the column in question.

enum column { a, b, c}

Map<column, string> str;

static {
 str.put(a, "select * from tbl where a = ? ");
 ...
}

then just grab one out of the map later based on the enum. String appends in sql statements have a way of becoming security problems in the future.