我在做一个图书管理系统,我想从一个控件TextBox6获得读者的编号(BH)
然后在readers表中获得最大借书的本数(maxjsl)和已经借了书的本数(yjsl)
然后进行比较,但是我用int变量的max和has记录这两个值,以便进行比较,但是我观察返回的值都是1,哪里出问题了???多谢大家指教
String sqlfindmax = "select maxjsl from readers where BH='"+this.textBox6.Text+"'";
OdbcCommand commfindmax = new OdbcCommand(sqlfindmax, connstring);
OdbcDataAdapter damax = new OdbcDataAdapter(commfindmax);
DataSet dsmax = new DataSet();
int max = damax.Fill(dsmax,"maxjsl");
connstring.Close();
//MessageBox.Show(max.ToString()); String sqlfindhas = "select yjsl from readers where BH='" + this.textBox6.Text+ "'";
OdbcCommand commfindhas = new OdbcCommand(sqlfindhas, connstring);
OdbcDataAdapter dahas = new OdbcDataAdapter(commfindhas);
DataSet dshas = new DataSet();
int has = dahas.Fill(dshas, "yjsl");
connstring.Close();
//MessageBox.Show(has.ToString());
然后在readers表中获得最大借书的本数(maxjsl)和已经借了书的本数(yjsl)
然后进行比较,但是我用int变量的max和has记录这两个值,以便进行比较,但是我观察返回的值都是1,哪里出问题了???多谢大家指教
String sqlfindmax = "select maxjsl from readers where BH='"+this.textBox6.Text+"'";
OdbcCommand commfindmax = new OdbcCommand(sqlfindmax, connstring);
OdbcDataAdapter damax = new OdbcDataAdapter(commfindmax);
DataSet dsmax = new DataSet();
int max = damax.Fill(dsmax,"maxjsl");
connstring.Close();
//MessageBox.Show(max.ToString()); String sqlfindhas = "select yjsl from readers where BH='" + this.textBox6.Text+ "'";
OdbcCommand commfindhas = new OdbcCommand(sqlfindhas, connstring);
OdbcDataAdapter dahas = new OdbcDataAdapter(commfindhas);
DataSet dshas = new DataSet();
int has = dahas.Fill(dshas, "yjsl");
connstring.Close();
//MessageBox.Show(has.ToString());
两个返回的都是影响的行数
并不是你查询到的值
string queryString = "select maxjsl from readers where BH='"+this.textBox6.Text+"'"; using (OdbcConnection connection = new OdbcConnection(connstring))
{
OdbcCommand command = new OdbcCommand(queryString, connection); connection.Open();
int max =0;
OdbcDataReader reader = command.ExecuteReader();
while (reader.Read())
{
max =Convert.ToInt32( reader[0]);
} reader.Close();
}