.net连接access数据库保存小数需要注意的一个问题

来源：互联网发布：db2如何连接数据库编辑：程序博客网时间：2024/05/22 06:30

         private void button2_Click(object sender, EventArgs e)
        {
            string connectionString = @"Provider=Microsoft.Jet.OLEDB.4.0; Data Source=D:/D/IEDP2/MainFrame/bin/Data/db1.mdb;Jet OLEDB:Database Password=;";
            string commandString = "select * from table1";

UpdateRows(connectionString, commandString, "table1");
}

        public static DataSet UpdateRows(string connectionString, string queryString, string tableName)
        {
            DataSet dataSet = new DataSet();
            using (OleDbConnection connection = new OleDbConnection(connectionString))
            {
                OleDbDataAdapter adapter = new OleDbDataAdapter();
                adapter.SelectCommand = new OleDbCommand(queryString, connection);
                OleDbCommandBuilder cb = new OleDbCommandBuilder(adapter);

connection.Open();

adapter.Fill(dataSet, tableName);

decimal myvalue = 12.4546444448885M;
dataSet.Tables[0].Rows[0]["col1"] = myvalue;

adapter.Update(dataSet, tableName);

connection.Close();
}

表table1的结构是col1 numeric(12,2)

并且有一行记录

经过上面的更新后数据库中的数值成为了:0.05

显然,access 数据库这样做了:

首先他取出12.4546444448885M的后12位(0.0546444448885M),去掉了前面的三位,然后保留两位有效数字

成为0.05.所以对access数据库更新时应先保留有效数字再保存.