Where to use 1=1 condition in where clause?

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.

Uma Shankar Patel13y

Where to use 1=1 condition in where clause?

2 Answers