如何通过数据库使用datetimepicker过滤日期

Question

Can you help me, i have a button to filtered data with date range base on my 2 datetimepicker (datefrom and dateto), Below is my code, and when i click the button it displays nothing. can you help me what is the problem? im new in C#.

MySqlConnection mcon = new MySqlConnection("datasource=localhost;port=3306;username=8888;password=888888");
MySqlDataAdapter mda = new MySqlDataAdapter("select * from bio_db.daily_data2 where Date between '" + datefrom.Value.ToString() + "' and '" + dateto.Value.ToString() + "' ", mcon);
mcon.Open();
DataSet ds = new DataSet();
mda.Fill(ds);
dbgrid1.DataSource = ds;
dbgrid1.Refresh();
mcon.Close();

Answer 1

You need to convert your dateFrom and dateTo values into DateTime

DateTime dtFrom =Convert.ToDateTime(DatePicker1.Text); //some DateTime value, e.g. DatePicker1.Text;
DateTime dtTo =Convert.ToDateTime(DatePicker2.Text); //some DateTime value, e.g. DatePicker1.Text;
MySqlConnection mcon = new MySqlConnection("datasource=localhost;port=3306;username=8888;password=888888");
MySqlDataAdapter mda = new MySqlDataAdapter("select * from bio_db.daily_data2 where Date between '" + dtFrom.ToString("MM/dd/yyyy")+ "' and '" + dtTo.ToString("MM/dd/yyyy") + "' ", mcon);
DataSet ds = new DataSet();
mda.Fill(ds);
dbgrid1.DataSource = ds;
dbgrid1.Refresh();
mcon.Close();

Answer 2

Hi guys i already figure out the missing link. Here's the corrected script. Thanks everyone!

DateTime dtFrom = Convert.ToDateTime(datefrom.Text); //some DateTime value, e.g. DatePicker1.Text;
DateTime dtTo = Convert.ToDateTime(dateto.Text); //some DateTime value, e.g. 
DatePicker1.Text;<n>MySqlConnection mcon = new MySqlConnection("datasource=localhost;port=3306;username=8888;password=8888888");
MySqlDataAdapter mda = new MySqlDataAdapter("select * from bio_db.daily_data2 where Date between '" + dtFrom.ToString("yyyy/MM/dd") + "' and '" + dtTo.ToString("yyyy/MM/dd") + "' ", mcon);

        System.Data.DataSet ds = new System.Data.DataSet();
        mcon.Open();
        mda.Fill(ds, "root");
        dbgrid1.DataSource = ds.Tables["root"];
        dbgrid1.Refresh();
        mcon.Close();

Answer 3

This line is missing:

MySqlCommandBuilder mcb = new MySqlCommandBuilder(mda);

Sources:

https://dev.mysql.com/doc/connector-net/en/connector-net-tutorials-data-adapter.html http://www.techonthenet.com/mysql/between.php

So the code should be:

MySqlConnection mcon = new MySqlConnection("datasource=localhost;port=3306;username=8888;password=888888");
string query = string.Format("select * from bio_db.daily_data2 where Date "
                           + "BETWEEN CAST('{0}' AS DATE) AND CAST('{1}' AS DATE) ", 
                             dateFrom.Value.ToString("M/d/yyyy"), 
                             dateTo.Value.ToString("M/d/yyyy"));
MySqlDataAdapter mda = new MySqlDataAdapter(query, mcon);
MySqlCommandBuilder mcb = new MySqlCommandBuilder(mda); //added code
mcon.Open();
DataTable dt = new DataTable();
mda.Fill(dt);
dbgrid1.DataSource = dt;
dbgrid1.Refresh();
mcon.Close();

Answer 4

Your database has the date value as date type and you are comparing the string with date which will not match.

You need to convert start and end date as date

select * from bio_db.daily_data2 where Date between STR_TO_DATE('" + datefrom.Value.ToString() + "','%m/%d/%Y') and STR_TO_DATE('" + dateto.Value.ToString() + "','%m/%d/%Y') "

You will need to specify exact format which is stored in database in place of '%m/%d/%Y' .

Use Parameterized Sql

Your current code is open to Sql injection it would be better to use parameterized sql . Don't concatenate values instead add parameters to query.

Answer 5

我认为您需要将 datefrom 和 dateto 值转换为数据库日期格式和类型