Question

its my first question here on this site.
well i have a problem regarding update query.

  ContentValues args = new ContentValues();
  args.put("j_id", str);

  db.update(TABLE_NAME2, args, null, null);

i just want to add “where” clause into it.

like

   UPDATE TABLE_NAME2
   SET j_id=str
   WHERE j_id = '-1'

So what should i do?

Answer 1

Instead of passing null as the third argument, you can pass the WHERE-clause. See the docs.

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In your case, this would look like this:

String value = "-1"; // Or something else
String column = "j_id"; // The Column for the WHERE-clause
db.update(TABLE_NAME2, args, column+" = ?", new String[]{value});

You should always use the prepared-statement syntax. Thus, you don’t actually add the value for the WHERE-clause in the String but use the fourth argument which takes a String-array to replace the ? in the WHERE-query-string.

The first element of the String-array is replaced with the first ? in the query-string and so on. So in the end, this creates a WHERE-clause like this:

WHERE j_id = '-1'