SQL: Is it possible to % CURDATE % in SELECT - mysql

I'm trying to use sql CURDATE(), in format "YYYY-MM-DD", to select items from yesterday but time column is in "YYYY-MM-DD HH-MM-SS" format.
Is it possible to put CURDATE between % %, something like in this example (which obviously doesn't work);
SELECT * FROM table WHERE created_at LIKE % CURDATE() - INTERVAL 1 day %
Or if there is no syntax variation which makes use of curdate & also that works, do please recommend another way if there is any in sql bag of tricks.

Don't use string functions as strings! If you want yesterday, you can use:
where created_at >= current_date - interval 1 day and
created_at < current_date
Plus, this can use an index.
Or, you can simplify this to:
where date(created_at) = current_date - interval 1 day
And this version does not use an index on created_at.

Related

MySQL query to select records with date

I have a database where data_fine is defined as TEXT and contains values such as "25-05-2021". I need to find all the records between the current date up to 8 days.
I tried the following query, but nothing is displayed.
SELECT * from tabella_raw where data_fine > DATE(NOW) and data_fine < DATE(NOW() + INTERVAL 8 DAYS)
What is the best and safe way to compare the date stored as TEXT with the current date?
You have to convert dates which cost a lot of processor time, so you should avoid that and save all in MySQL date yyyy-MM-dd hh:mm:ss
Also you can use CURDATE() to get the the current date
Last the parameter fo INTERVAL IS DAYnot DAYS
SELECT STR_TO_DATE("25-05-2021",'%d-%m-%Y');
SELECT * from tabella_raw where STR_TO_DATE(data_fine,'%d-%m-%Y') > Curdate() and STR_TO_DATE(data_fine,'%d-%m-%Y') < CURDATE() + INTERVAL 8 DAY;
Try use STR_TO_DATE function
SELECT * from tabella_raw where STR_TO_DATE(data_fine, '%d-%m-%Y') > DATE(NOW) and STR_TO_DATE(data_fine, '%d-%m-%Y') < DATE(NOW() + INTERVAL 8 DAYS)
You are trying to use a text field as a date, so you need to convert the text to a date to use date functions.

Using DATE_ADD with CURRENT_DATE to find things that are happening today in a table

I'm trying to select my table where I'm looking at things that happened today.
I have it set up as:
WHERE date between CURRENT_DATE and DATE_ADD(CURRENT_DATE, 1, DAY);
I keep getting the error that DATE_ADD is not a valid identifier. I'm using mySQL.
I also tried DATEADD() but I don't think that one works in MYSQL.
Do not use between for this! That includes both endpoints. Instead:
where date >= current_date and
date < current_date + interval 1 day
Or:
where date >= current_date and
date < date_add(current_date, interval 1 day)
You (presumably) do not want midnight between today and tomorrow.
By the way, if date is really just a date and not a datetime, the above will work, but you can also write:
where date = current_date
I strongly discourage you from using:
where date(date) = current_date
because this prevents an index on date from being used.
Sometimes people confuse MySQL and Oracle because Oracle owns both. In Oracle, this would look like:
where date >= current_date and
date < current_date + interval '1' day
That would actually work in MySQL as well. Or using Oracle-specific features:
where date >= trunc(sysdate) and
date < trunc(sysdate) + interval '1' day
Issue with your code: DATE_ADD() accepts a date as first argument and an interval expression as second argument
Consider:
WHERE mydate BETWEEN CURRENT_DATE() AND DATE_ADD(CURRENT_DATE(), INTERVAL 1 DAY);
Or you can use ADDDATE(), which, as second argument, can accept either an interval or a number of days
WHERE mydate BETWEEN CURRENT_DATE() AND ADDDATE(CURRENT_DATE(), 1);
Note 1: please note that CURRENT_DATE() is a function. Although MySQL also accepts spelling CURRENT_DATE and CURRENT_DATE(), I find that that the parentheses make the purpose clearer.
Note 2: as for DATEADD(), it just does not exist in MySQL.
older MySQL versions you can do like this.
where date between curdate() and curdate() + 1;
and this is still supported up to this current versions of mySQL.

select data on specific date

I want to retrieve records from db according to date format YYYY,MM,dd given by me but the column type is YYYY,MM,dd hh:mm:ss.
tried to use Date format function
SELECT *
FROM tabl.error_logs
where created_at = DATE_FORMAT(NOW(),'%Y-%m-%d'- INTERVAL 3 DAY);
I expect the created date will be 2019-06-08, but the result is empty
What is the actual datatype of created_at column?
This answer is going to ignore that funkiness with the format with commas, and assume that it's not character type data, and that it's DATETIME or TIMESTAMP.
Normative pattern for predicates on DATETIME and TIMESTAMP columns is a range comparison.
For example, to get all datetimecol values on June 10th, then something like this:
WHERE t.datetimecol >= '2019-06-10 00:00:00'
AND t.datetimecol < '2019-06-11 00:00:00'
Typically, I would just pass that one date value, and let MySQL figure out the next day. If we omit the time portion, MySQL will assume 00:00:00
WHERE t.datetimecol >= '2019-06-10' + INTERVAL 0 DAY
AND t.datetimecol < '2019-06-10' + INTERVAL 1 DAY
For performance, to allow MySQL to make effective use of a range scan operation on a suitable index, we want to avoid wrapping the column reference in a function. That is, specifying DATE(t.datetimecol) in a condition in the WHERE clause is going to force MySQL to evaluate the DATE() function on every row in the table.
With references to the bare column, that allows MySQL to make use of an index, if a suitable index is available.
e.g.
SELECT e.*
FROM tabl.error_logs e
WHERE e.created_at >= DATE(NOW()) + INTERVAL -3 DAY
AND e.created_at < DATE(NOW()) + INTERVAL -2 DAY
note that we can easily test those expressions in the WHERE clause, to verify they are returning what we want, and tweak as necessary:
SELECT DATE(NOW()) + INTERVAL -3 DAY
, DATE(NOW()) + INTERVAL -2 DAY
To make your query sargable, you need ...
SELECT *
FROM tabl.error_logs
WHERE created_at >= DATE_SUB(CURDATE(), INTERVAL 3 DAY)
AND created_at < DATE_SUB(CURDATE(), INTERVAL 2 DAY)
This selects all values of created_at on or after midnight three days ago, up to but not including < midnight two days ago. It uses a range scan on an index on created_at if one is available.
You coudl use date_sub()
SELECT *
FROM tabl.error_logs
where date(created_at) = DATE_SUB(date(now()), INTERVAL 3 DAY);
if the column created_at is a date then you could avoid the date() function and let the index (if present) work for this column
SELECT *
FROM tabl.error_logs
where created_at = DATE_SUB(date(now()), INTERVAL 3 DAY);

MySQL Select last 7 days

I read some posts here and seems like nothing special but I can not still select the entries of the last days.
SELECT
p1.kArtikel,
p1.cName,
p1.cKurzBeschreibung,
p1.dLetzteAktualisierung,
p1.dErstellt,
p1.cSeo,
p2.kartikelpict,
p2.nNr,
p2.cPfad
FROM
tartikel AS p1 WHERE DATE(dErstellt) > (NOW() - INTERVAL 7 DAY)
INNER JOIN
tartikelpict AS p2
ON (p1.kArtikel = p2.kArtikel) WHERE (p2.nNr = 1)
ORDER BY
p1.kArtikel DESC
LIMIT
100;', $connection);
If I add the between today and last 7 days my Code will not output anything.
The WHERE clause is misplaced, it has to follow the table references and JOIN operations.
Something like this:
FROM tartikel p1
JOIN tartikelpict p2
ON p1.kArtikel = p2.kArtikel
AND p2.nNr = 1
WHERE p1.dErstellt >= DATE(NOW() - INTERVAL 7 DAY)
ORDER BY p1.kArtikel DESC
EDIT (three plus years later)   
The above essentially answers the question "I tried to add a WHERE clause to my query and now the query is returning an error, how do I fix it?"
As to a question about writing a condition that checks a date range of "last 7 days"...
That really depends on interpreting the specification, what the datatype of the column in the table is (DATE or DATETIME) and what data is available... what should be returned.
To summarize: the general approach is to identify a "start" for the date/datetime range, and "end" of that range, and reference those in a query. Let's consider something easier... all rows for "yesterday".
If our column is DATE type. Before we incorporate an expression into a query, we can test it in a simple SELECT
SELECT DATE(NOW()) + INTERVAL -1 DAY
and verify the result returned is what we expect. Then we can use that same expression in a WHERE clause, comparing it to a DATE column like this:
WHERE datecol = DATE(NOW()) + INTERVAL -1 DAY
For a DATETIME or TIMESTAMP column, we can use >= and < inequality comparisons to specify a range
WHERE datetimecol >= DATE(NOW()) + INTERVAL -1 DAY
AND datetimecol < DATE(NOW()) + INTERVAL 0 DAY
For "last 7 days" we need to know if that mean from this point right now, back 7 days ... e.g. the last 7*24 hours , including the time component in the comparison, ...
WHERE datetimecol >= NOW() + INTERVAL -7 DAY
AND datetimecol < NOW() + INTERVAL 0 DAY
the last seven complete days, not including today
WHERE datetimecol >= DATE(NOW()) + INTERVAL -7 DAY
AND datetimecol < DATE(NOW()) + INTERVAL 0 DAY
or past six complete days plus so far today ...
WHERE datetimecol >= DATE(NOW()) + INTERVAL -6 DAY
AND datetimecol < NOW() + INTERVAL 0 DAY
I recommend testing the expressions on the right side in a SELECT statement, we can use a user-defined variable in place of NOW() for testing, not being tied to what NOW() returns so we can test borders, across week/month/year boundaries, and so on.
SET #clock = '2017-11-17 11:47:47' ;
SELECT DATE(#clock)
, DATE(#clock) + INTERVAL -7 DAY
, #clock + INTERVAL -6 DAY
Once we have expressions that return values that work for "start" and "end" for our particular use case, what we mean by "last 7 days", we can use those expressions in range comparisons in the WHERE clause.
(Some developers prefer to use the DATE_ADD and DATE_SUB functions in place of the + INTERVAL val DAY/HOUR/MINUTE/MONTH/YEAR syntax.
And MySQL provides some convenient functions for working with DATE, DATETIME and TIMESTAMP datatypes... DATE, LAST_DAY,
Some developers prefer to calculate the start and end in other code, and supply string literals in the SQL query, such that the query submitted to the database is
WHERE datetimecol >= '2017-11-10 00:00'
AND datetimecol < '2017-11-17 00:00'
And that approach works too. (My preference would be to explicitly cast those string literals into DATETIME, either with CAST, CONVERT or just the + INTERVAL trick...
WHERE datetimecol >= '2017-11-10 00:00' + INTERVAL 0 SECOND
AND datetimecol < '2017-11-17 00:00' + INTERVAL 0 SECOND
The above all assumes we are storing "dates" in appropriate DATE, DATETIME and/or TIMESTAMP datatypes, and not storing them as strings in variety of formats e.g. 'dd/mm/yyyy', m/d/yyyy, julian dates, or in sporadically non-canonical formats, or as a number of seconds since the beginning of the epoch, this answer would need to be much longer.
Since you are using an INNER JOIN you can just put the conditions in the WHERE clause, like this:
SELECT
p1.kArtikel,
p1.cName,
p1.cKurzBeschreibung,
p1.dLetzteAktualisierung,
p1.dErstellt,
p1.cSeo,
p2.kartikelpict,
p2.nNr,
p2.cPfad
FROM
tartikel AS p1 INNER JOIN tartikelpict AS p2
ON p1.kArtikel = p2.kArtikel
WHERE
DATE(dErstellt) > (NOW() - INTERVAL 7 DAY)
AND p2.nNr = 1
ORDER BY
p1.kArtikel DESC
LIMIT
100;

Select query for two weeks ago

In my database table I have a field for date (varchar field to save date in yy-mm-dd format ), now I want to select records for two weeks ago.
How can i do it ?
Implicit date arithmetic is fairly flexible in MySQL. You can compare dates as strings without explicit use of CAST() or DATE(), but you're trusting MySQL to interpret your format correctly. Luckily for you, it will do just fine with yy-mm-dd.
I would recommend using BETWEEN and INTERVAL so that your query is easily readable; for example:
SELECT * FROM Holidays
WHERE Date BETWEEN (NOW() - INTERVAL 14 DAY) AND NOW();
The only trick with BETWEEN is that you have to put the lower bound first and the upper bound second; for example, if you write BETWEEN 5 AND 2, this always evaluates to FALSE because there is no value that can be greater than or equal to 5 while also being less than or equal to 2.
Here's a demo of the query in action at SQL Fiddle, and a list of the recognized INTERVAL expressions in MySQL.
Note that the parentheses around the expression NOW() - INTERVAL 14 DAY are not required but I would recommend using them here purely for the sake of clarity. It makes the predicate clause just a little bit easier to read in the absence of proper syntax highlighting, at the expense of two characters.
Ideally you should be using date types to store dates, but being that's not the case, you should look into casting to date then comparing.
select * from yourtable where cast (yourdate as Date) BETWEEN Date_Add(CURDATE(), INTERVAL -21 Day) and Date_Add(CURDATE(), INTERVAL -14 Day)
Note, this is untested and may need a little tweaking, but should give you a general idea of what you need to do.
Also, if it's possible, you should really look into converting the varchar field to a date field....they have date types to prevent this sort of thing from happening, although i know changing field types isn't always a possibility.
you can simply do with ADDDATE to get 14 days ago. compare string with date will work.
SELECT *
FROM your_table
WHERE your_date >= ADDDATE(NOW(), -14) AND your_date < NOW()
I use this for select data in past of past
SELECT * FROM Holidays
WHERE a.dDate >= DATE( NOW( ) ) - INTERVAL 14
DAY AND a.dDate <= DATE( NOW( ) ) - INTERVAL 8