黄聪：在C#中建立复杂的、灵活的SQL查询/命令

string statement = "SELECT TOP " + maxRecords + " * FROM Customers ";

string whereConcatenator = "WHERE ";

if (companyNameTextBox.Text.Length > 0)

{

statement += whereConcatenator;

statement += "CompanyName like "" + companyNameTextBox.Text + "%" ";

whereConcatenator = "AND ";

}

if (cityTextBox.Text.Length > 0)

{

statement += whereConcatenator;

statement += "City like "" + cityTextBox.Text + "%" ";

whereConcatenator = "AND ";

}

if (countryComboBox.SelectedItem != null)

{

statement += whereConcatenator;

statement += "Country = "" + countryComboBox.SelectedItem + "" ";

whereConcatenator = "AND ";

}