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date in sql query with asp.net program

On the server, the date format is mm-dd-yyyy. On my local machine, the date format is mm/dd/yyyy.
I have the following code:
DateTime FrDate, Todate;
string yy = "2020";
string mm = "04";
string dd = "01";
DateTime.TryParse(mm + "/" + dd + "/" + yy, out FrDate);
And then I am trying to run this query:
select * from helpdesk_tranactions where compl_date `= '" + FrDate.ToShortDateString() + "'
This is working fine when I run on my local machine, where the date format is mm/dd/yyyy.
However, when this code is deployed to the server, the same query is not working (since the date format is mm-dd-yyyy).
The error I get is:
The conversion of a varchar data type to a datetime data type resulted in an out-of-range value.
The statement has been terminated.
How can I write this query in such a way that it will work regardless of the system date formatting?

Noooooooo! If you're worried about string formats for SQL date values something has already gone horribly wrong.
The column in your database should be a Date, Timestamp, or DateTime rather than varchar field, and if that's true there is no human-readable format! The data is binary. What you see is a convenience shown to you by your management tool or connection library. If you're not using one of the date types for the column column, you should fix the schema, because it really is broken.
Once you have confirmed or fixed the column so you know it is a DateTime value, you should also be using DateTime variables in the C# code. And once you're doing that, the correct way to include those values in a query looks like this (assuming MySql because of the backtick, but you should also tag the question with the correct database engine):
string sql = "select * from helpdesk_tranactions where compl_date = #compl_date";
using (var cn = new MySqlConnection("connection string here"))
using (var cmd = new MySqlCommand(sql, cn))
{
cmd.Parameters.Add("#compl_date", MySqlDbType.DateTime).Value = FrDate;
cn.Open();
// ...
}
Notice this assigns the FrDate field directly to the query parameter. There's no conversion in your code to worry about.
This technique is also the best and only truly safe way to avoid certain other types of problem with sql.

Convert DateTime format to Another DateTime Format In C#

In my C# project I need system date time to another specific date time format.
My system datetime format is like "15/03/2017 9:25 AM" --->that can be changed according to computer wich my program run.
But I need to parse that datetime format to another date time format something like "2017-03-15 9:25 AM"----> save date in SQL datebase accept this format only.
I need Assign this to variable to Datetime Variable not need save in String variable.
I tried this code but not working
string datetimesss = DateTime.Now.ToString("yyyy-MM-dd hh:mm:ss")
It returns
// value of datetimesss="2017-03-15 09:33:25"
Then i parse again to date time format
DateTime dates = DateTime.Parse(datetimesss);
It returns
// value of dates ="15/03/2017 9:42:43 AM"
Convert back to my computer datetime format .How can I convert any datetime format to DateTime "yyyy-MM-dd hh:mm:ss"
Thank You!

You should avoid strings and just keep your data in DateTime variables. ADO.Net already knows how to translate between .NETs DateTime and SQL Server's datetime - and neither of these has a format (both of them, internally, are just numbers. .NETs DateTime is a count of 100ns intervals since 01/01/0001. SQL Server's datetime is a count of whole and fractional days since 01/01/1900).
Something like:
var updateCommand = new SqlCommand(
"UPDATE [User] SET Last_loign_date =#LastLoginDate"
,conn); //Assume conn is an SqlConnection object
updateCommand.Parameters.Add("#LastLoginDate",SqlDbType.DateTime).Value = DateTime.Now
or, in the alternative, why not use the database server time rather than passing it:
string sqlupdatepassword = "UPDATE [User] SET Last_loign_date =current_timestamp";

If sql server language is set as us-english then your date - > '15/03/2017 9:25 AM' will be considered as text and converting into date will not give correct results. You need create date based on day,month and year from your given date by using string functions. Use the below code to get required output :
declare #date varchar(30) = '15/03/2017 9:25 AM'
select cast(left(parsename(replace(#date,'/','.'),1),4) +
parsename(replace(#date,'/','.'),2) +
parsename(replace(#date,'/','.'),3) as datetime) +
ltrim(stuff(parsename(replace(#date,'/','.'),1),1,4,''))

Finaly I got the point,
I parse DateTime to String
string sqlupdatepassword = "UPDATE [User] SET Last_loign_date ='" + DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss tt") + "'";
In SQl database "Last_loign_date" is datetime format.
this may not correct, but this worked for me.
thanks!

Convert date time into specified format in PostgreSQL query

For converting datetime into SQL Server CE, I am using below format
var date = "CONVERT(datetime,'" +
((DateTime) DateTime.UtcNow).ToString("yyyyMMdd HH:mm:ss tt", new CultureInfo("en-us"))
+ "',112)";
For Oracle:
var date = "TO_DATE('"
+ ((DateTime)DateTime.UtcNow).ToString("MMddyyyy hh:mm:ss tt")
+ "', 'mmddyyyy hh:mi:ss')";
And for MySQL:
var date = "STR_TO_DATE('"
+ ((DateTime)DateTime.UtcNow).ToString("yyyyMMdd HH:mm:ss", new CultureInfo("en-us"))
+ "','%Y%m%d %H:%i:%s')";
Can anyone tell me how to convert the same in PostgreSQL?
Note: I am using timestamp datatype

You can use the to_char function to format a timestamp:
SELECT TO_CHAR(current_timestamp, 'MMDDYYYY HH24:MI:SS')
EDIT:
To answer the question in the comments, the same call could be applied in an insert statement:
INSERT INTO my_table
(formatted_timestamp_column, some_other_column)
VALUES (TO_CHAR(current_timestamp, 'MMDDYYYY HH24:MI:SS'), 'some_value')

If you want a very simple approach, you can also use this:
var date = $"'{new NpgsqlDateTime(DateTime.UtcNow)}'";
Edit: This has been deprecated since version 7.* of Npgsql. See this: https://github.com/npgsql/npgsql/issues/2009

With PostgreSQL, you can use the code from Oracle, just take to_timestamp instead of to_date.
The difference is that datein PostgreSQL is a real date and not a timestamp with second precision like it is in Oracle.
So while you can use to_date as you do above, the result will not have any time information.
By, the way, your Oracle format is wrong. You probably want to use HH24 and not HH for the "hour" part.

Conversion failed when converting date and/or time from character string

I am trying to query the database where date is between today and yesterday but am getting error saying Conversion failed when converting date and/or time from character string.
My query is below with my parameters today and yesterday
string today = new DateTime(DateTime.Now.Year, DateTime.Now.Month, DateTime.Now.Day).ToString("yyyy-MM-dd");
string yesterday= new DateTime(DateTime.Now.Year, DateTime.Now.Month, DateTime.Now.Day-1).ToString("yyyy-MM-dd");
string errorsPerHourQuery = "WITH data_CTE(ErrorDay)" +
"AS(" +
"SELECT DATEPART(hh, Date) AS ErrorDay FROM cloud.ErrorLog " +
"WHERE Date BETWEEN '#yesterday' AND '#today' " +
"AND CAST(Message AS varchar(200)) ='#message'"+
")" +
"SELECT ErrorDay, COUNT(*) AS count FROM data_CTE GROUP BY ErrorDay ORDER BY ErrorDay";
conn.Open();
cmd.Parameters.AddWithValue("#message", message);
cmd.Parameters.AddWithValue("#yesterday", yesterday);
cmd.Parameters.AddWithValue("#today", today);
cmd.CommandType = CommandType.Text;

You must remove simple cote ' from parmeters in query :
..BETWEEN #yesterday AND #today
You don't need to create today and yesterday with specific format, you can simply get variable like :
var today = DateTime.Today;
var yesterday = DateTime.Today.AddDays(-1);
and use Parameter with SqlDbType.DateTime and then pass the DateTime directly to the parameter (do not need to convert).
cmd.Parameters.Add("#yesterday", SqlDbType.DateTime).Value = yesterday
cmd.Parameters.Add("#today", SqlDbType.DateTime).Value = today

First off, you're calculating your today and yesterday wrong. Here's the correct way:
var today = DateTime.Today;
var yesterday = today.AddDays(-1);
And regaring query: remove ticks (') from around your named parameters so that your query reads ...BETWEEN #yesterday and #today... and you'll be all set.

Problem is that you are quoting your command parameters which is getting considered as string literal instead of parameter as seen below.
WHERE Date BETWEEN '#yesterday' AND '#today'
You should change it to
WHERE [Date] BETWEEN #yesterday AND #today

There are lots of good points in the other answers especially. #Abdellah does a good job of teaching the datetime datatype and the appropriate value, but your SQL query itself needs work and may be why you are not getting what you want. Because just like the #yesterday and #today you need to remove the ''(ticks) from #message. Then you can do your query in 1 step you don't need the cte. Plus if you aren't going to pass any dates other than yesterday or today there is no need for parameters use SQL's built in functions.
So remove all of the ticks around all of your parameters (#yest...)
Here is a SQL query that should work for you:
SELECT
ErrorHour = DATEPART(HH,[Date])
,[Count] = COUNT(*)
FROM
cloud.ErrorLog
WHERE
--use this line from midnight yesterday to midnight today
CAST([Date] AS DATE) BETWEEN CAST(GETDATE() - 1) AND CAST(GETDATE())
--what is the datatype for message does it really need to be cast?
AND CAST([Message] AS VARCHAR(200)) = #Message
GROUP BY
DATEPART(HH,[Date])
ORDER BY
ErrorHour
Note I put ErrorHour you are welcome to change to ErrorDay, but you are counting errors per hours not days, to change what you are counting simply change your DATEPART() to be the time component you want, e.g. minutes, etc..
Next Do you really need to cast Message field?
On the dates. Are you wanting everything today and yesterday or really just yesterday? If just yesterday swap this line into the query for the other date line:
--if you really just want yesterday midnight to 11:59:59 PM the it should be
CAST([Date] AS DATE) = CAST(GETDATE()-1 AS DATE)
Next if you really really want to pass yesterday and today as parameters and you want all of yesterday and all of today do the following and update your parameter definitions in your code as the other posts suggest.
--use this line from midnight yesterday to midnight today
CAST([Date] AS DATE) BETWEEN CAST(#yesterday AS DATE) AND CAST(#Today AS DATE)

C# store DateTime to Timestamp column in MYSQL

How to convert C# Datetime.Today, into Timestamp format 10/20/2011 12:00:00 in mysql?

If you want to get the date time as a string in that format then you can do...
string dt = DateTime.Now.ToString("MM/dd/yyyy HH:mm:ss");
See here for extra formatting options for the DateTime ToString method
Though from my understanding of MySQL it will accept a timestamp in the format yyyy-MM-dd HH:mm:ss. I would recommend doing this as it will ensure dates like 05/08/2011 are parsed correctly for the right month and day...
string dt = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss");

Try this:
DateTime.Now.ToString("MM/dd/yyyy HH:mm:ss");
and if you want more/other time formats, check this.

You can use something like following and use return value as timestamp for Sql.
public static string GiveMeTimestamp(DateTime value)
{
return value.ToString("yyyy/MM/dd HH:mm:ss:ffff");
}

Use the overloaded ToString method which takes a string argument for the format.

This Possibly may assist someone with the same approach and thought that I had:
To test directly in MYSQL Workbench:
INSERT into tblDemo VALUES (898,CURRENT_TIMESTAMP());
create table tblDemo (ScenarioID INT(10),
ProcessTime DATETIME DEFAULT CURRENT_TIMESTAMP() NOT NUll);
Now compile the string in your C# Code like so:
string query = "INSERT into tblDemo " +
"VALUES (" + ScenarioID + "," + " CURRENT_TIMESTAMP())";
Note the CURRENT_TIMESTAMP() in quotes in the above query
Output:
'2021-03-04 17:52:30'