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Where to use 1=1 condition in where clause?

    This method mainly used in injection ............

    If you don't know  the list of conditions at compile time and it will built at run time, Then you can made a condition with “where 1=1”. and for other conditions that will affect run time, use

    and .

    Example

    StringBuilder sb = new StringBuilder();
    sb.Append("SELECT * FROM Products");  // Your query
    sb.Append(" WHERE 1=1"); // always true condition
    // append query's where clause
    if (catID != 0)
    {
    sb.Append(" AND categoryID= {0}", catID);
    }
    if (minPrice > 0)
    {
    sb.Append(" AND itemPrice >= {0}", minPrice);
    }
    SqlCommand cmd = new SqlCommand(sb.ToString(), cnn);
    SqlDataReader dr = cmd.ExecuteReader();
    // your code to read data from dr.