I'm trying to make some vchar values searchable based on a date.
The strings I have to work with look like this:
1/7/2006 12:45:24 AM
1/7/2006 1:18:36 AM
1/7/2006 1:21:43 AM
1/7/2006 1:32:09 AM
3/30/2006 12:32:10 PM
3/30/2006 1:19:30 PM
3/30/2006 1:20:44 PM
So first off let's get rid of the AM.. PHPMyAdmin the sql query is:
SELECT trim('AM' FROM `orderdate`) FROM tblorders
This works to get rid of the AM now let's set the values as a variable and try to wrap a string to str_to_date() around the results:
SELECT trim('AM' FROM `orderdate`) AS `value`, STR_TO_DATE(`value`,'%d,%m,%Y') FROM tblorders
This yields value as an unknown column. How else do you string two function values together so as to then use them to be filtered such as WHERE value > 2/1/2006 ?
You can compose functions like this:
select str_to_date(trim('AM' from orderdate), '%m/%d/%Y')
Note that I also corrected your date format to match your data. You don't actually need to trim those values to use str_to_date on them, just this will work fine:
select str_to_date(orderdate, '%m/%d/%Y')
If you want to use that in your WHERE clause then put the function calls in there:
select trim('AM' from orderdate), str_to_date(orderdate, '%m/%d/%Y')
from your_table
where str_to_date(orderdate, '%m/%d/%Y') > '2006-01-02'
and let the optimizer recognize the repetition or use a derived table:
select value, the_date
from (
select trim('AM' from orderdate) as value, str_to_date(orderdate, '%m/%d/%Y') as the_date
from your_table
) dt
where the_date > '2006-01-02'
Note the use of ISO 8601 dates in the query, that format is unambiguous and any database worth using will understand it regardless of your locale settings.
I'd also recommend that you fix your schema to use real timestamps instead of those strings.
Related
I have a series of dates in my database that are in String format.
I am trying to convert these to date using the following command:
SELECT STR_TO_DATE(Date_Scanned, '%d/%m/%Y')FROM urls WHERE Date_Scanned
BETWEEN "01/02/2018" AND "05/04/2018"
My problem seems to occur when the day contains a 0, for example the below command returns all desired dates:
SELECT STR_TO_DATE(Date_Scanned, '%d/%m/%Y')FROM urls WHERE Date_Scanned
BETWEEN "01/02/2018" AND "15/04/2018"
However, this command returns zero results:
SELECT STR_TO_DATE(Date_Scanned, '%d/%m/%Y')FROM urls WHERE Date_Scanned
BETWEEN "01/02/2018" AND "05/04/2018"
I believe there is no error in your code but instead it is returning empty row. The reason is because the parameter you are passing is evaluated as a string and not as a date. Your WHERE clause filters the column Date_Scanned in string.
If you wanted to filter the column based on real date datatype, you should be using the STR_TO_DATE() in the WHERE clause and not in the SELECT clause.
SELECT STR_TO_DATE(Date_Scanned, '%d/%m/%Y')
FROM urls
WHERE STR_TO_DATE(Date_Scanned, '%d/%m/%Y') BETWEEN '2018-02-01' AND '2018-04-05'
However, based on your comment, you wanted to stick the format you want so you have to cast the column as well as the value. But why make it more complicated?
WHERE STR_TO_DATE(Date_Scanned, '%d/%m/%Y')
BETWEEN STR_TO_DATE('01/02/2018', '%d/%m/%Y')
AND STR_TO_DATE('05/04/2018', '%d/%m/%Y')
I'm querying
SELECT * FROM tempLog WHERE date BETWEEN '23-03-2017' AND '02-04-2017'
and the result is null. How to fix this. But
SELECT * FROM tempLog WHERE date BETWEEN '23-03-2017' AND '30-03-2017'
giving me the correct result.
Note:- tempLog is the table name.
You should store dates in date format or atleast correctly formatted string (YYYY-MM-DD).
For now you can use str_to_date to convert the string to date and compare:
select *
from tempLog
where str_to_date(date, '%d-%m-%Y') between '2017-03-23' and '2017-04-02';
However note that this will hinder the optimizer from using index on the column if any.
The correct remedy of the situation is fixing the table structure.
According to the documentation, you're supposed to use this format when writing a date: 'YYYY-MM-DD' (although it says it may accept 'YYYYMMDD' or even YYYYMMDD in some contexts).
in a database table I have made a date attribute but I have set it's type to varchar and not Date.
My question is, will I still be able to compare such dates in a SQL Query?
Dates in my DB are stored in this format:
dd/mm/yyyy hh:mm:ss
I have to do a SQL Query in PHP that looks something like this:
SELECT *
FROM DBtable
WHERE DBname='$name' AND date>='01/01/2015' AND date<='01/09/2015';
I would appreciate an example how to do this.
Thank you for your help.
You'll need to convert/cast to compare:
SELECT *
FROM DBtable
WHERE DBname='$name'
AND CAST(date AS DATETIME) >='2015-01-01'
AND CAST(date AS DATETIME)<='2015-01-09'
;
Much better to store values as the appropriate data types to avoid this inefficiency. You could also use DATE instead of DATETIME if you want to compare without the time component. Syntax and available datatypes vary by database, so the above may need adjustment.
Update: Since you're using MySQL, you can use the following:
SELECT *
FROM DBtable
WHERE DBname='$name'
AND STR_TO_DATE(`date`, '%d/%c/%Y') >= '2015-01-01'
AND STR_TO_DATE(`date`, '%d/%c/%Y') <= '2015-01-09'
;
Yes you can cast a Varchar to a Date. Here is an example:
SELECT
CAST(date_column AS DATETIME)
FROM
TABLE_NAME
In your case it might look like:
SELECT *
FROM DBtable
WHERE DBname='$name'
AND CAST(date AS DATETIME) >='01/01/2015'
AND CAST(date AS DATETIME) <='01/09/2015';
You can cast or convert a varchar to a date or datetime before you do any comparisons.
But you'd have to do it every single time you compare the date to something. That's because the following comparisons are all true if you compare them as varchar:
'2/1/2015' > '1/5/2016'
'25/1/2015' > '15/2/2015'
'11/1/2015' < '3/1/2015'
You'll also need to convert if you want to pull out some time-based aspect of the dates, such as any records where the hour was before 8:00 AM. There is no easy way to do that if your date is a varchar.
And that assumes that the value in your database can always be parsed into a date! If an empty string or some other kind of data gets in there, CONVERT(datetime, MyColumn) will fail.
So I would strongly recommend that you change your column to be a date or datetime. It will make your life much easier.
I'm trying to query a MySQL database and return all records within a given date range and which also contain the substring 'bank' in the content column.
The format of the 'time' field I refer to is mm/dd/yyyy hh:mm:ss.
Here's the statement I've come up with but MySQL Workbench is giving me issues:
SELECT *
FROM blogs
WHERE ((‘time’ BETWEEN “04/01/2011 00:00:00” AND “04/15/2011 23:59:59”)
AND (‘content’ LIKE ‘%bank%’))
How about trying this:
SELECT *
FROM blogs
WHERE `time` BETWEEN '2011-04-01 00:00:00' AND '2011-04-15 23:59:59'
AND `content` LIKE '%bank%';
This works if your time field is in fact a timestamp. If time is not a timestamp then you will have to go with something like the answer from McAdam331 but I'm hoping your database is using the correct types for the kind of data you are asking it to store.
single ' or double " quotes around values and ticks ` around field names. I also changed the date format to yyyy-mm-dd hh:mm:ss and eliminated some unnecessary parentheses.
http://sqlfiddle.com/#!9/730bd/1/0
It would be helpful if you posted the structure of the table when posting questions like this so we can be sure to give the right answer.
It isn't a good idea to store dates like that in MySQL. The DBMS has Date and Time Types you can use to store that information.
If changing the database isn't an option, you can convert a string to a date object using the STR_TO_DATE function, which takes in a date string and the format that it is in already and returns a date.
MySQL stores dates in the 'YYYY-MM-DD' format, so to get that format you can try something like this:
SELECT STR_TO_DATE('04/01/2011', '%m/%d/%Y');
Which will return a date object for that day. Note the capital Y.
Then it becomes much easier to query between dates, like this:
SELECT *
FROM myTable
WHERE STR_TO_DATE(dateString, '%m/%d/%Y %H:%i:%s') BETWEEN STR_TO_DATE('04/01/2011 00:00:00', '%m/%d/%Y %H:%i:%s') AND STR_TO_DATE('04/15/2011 23:59:59', '%m/%d/%Y %H:%i:%s')
AND content LIKE '%bank%';
Here is an SQL Fiddle example, and here is a link that has the formatting characters you need.
I am trying folowing on my_table where modifiedtime is of type datetime
select DATE_FORMAT(modifiedtime,'%d-%m-%Y') from my_table
where DATE_FORMAT(modifiedtime,'%d-%m-%Y') between '05-11-2013' and '28-11-2013';
The query gives me some other record too which are not falls between above dates, for example there is a record in result set dated '04-01-2014'
select DATE_FORMAT(modifiedtime,'%d-%m-%Y') from my_table
where DATE_FORMAT(modifiedtime,'%d-%m-%Y')='05-11-2013'
this query works fine and gives all the records for the given date
why the first behaves like that?
How can i correct it?
what is the efficient way to implement it?
such that i can get all the records only between given two dates.
SELECT
DATE_FORMAT(modifiedtime, '%d-%m-%Y')
FROM
my_table
WHERE
modifiedtime BETWEEN STR_TO_DATE('05-11-2013', '%d-%m-%Y') AND STR_TO_DATE('28-11-2013', '%d-%m-%Y');
DATE_FORMAT() returns TEXT type column and dates can't be applied.
Use without DATE_FORMAT in the WHERE
select DATE_FORMAT(modifiedtime,'%d-%m-%Y') from my_table
where modifiedtime between '05-11-2013' and '28-11-2013';
you DATE_FORMAT function converts the column modifiedtime to String.
and hence in your first query you do a string comparison rather then a date comparison.
Also your date literal is not incorrect. It must be of form YYYY-MM-DD
select DATE_FORMAT(modifiedtime,'%d-%m-%Y') from my_table
where cast(modifiedtime as date) between '2013-11-05' and '2013-11-28';