I have a SQL query that fetches 50million records .
I want to assign a constant value to each row in the results which should be different everytime I run the query.
So I decided to use system date in the query.
My query looks like :
SELECT (SYSDATE,'DD-MM-YYYY - HH:MM:SS'), column1,column2,column3
FROM my_table
But by the time query execution ends I get different values of HH:MM:SS in the sysdate column.
Is there a way I can make this constant?
Currently My Results Look Like:
SYSDATE
01-03-2019 01:20:55
01-03-2019 01:20:56
01-03-2019 01:20:57
01-03-2019 01:20:58
01-03-2019 01:20:59
This is because there are so many records the database takes time to select all of them.
You can create a variable to hold the sysdate before you start the query and select it along with your columns:
SET #Date = (SYSDATE,'DD-MM-YYYY - HH:MM:SS');
SELECT #Date, column1,column2,column3
FROM my_table;
Related
i've issue I try this query, do not return any rows. just 0 rows. Even tho there is data matching the request..
select * from repairshop_reservations where date = DATE_FORMAT("11/06/2017 20:00:00", '%d/%m/%Y %H:%i:%s"');
Currently my content of the selected table look like this
The data value of column Date is datetime
you could use str_to_date in this way you can control the proper formatting of the date when you don't use the standard mysql format
select * from repairshop_reservations
where date = str_to_date('11/06/2017 20:00:00', '%d/%m/%Y %H:%i:%s');
You are not inserting a column in your table, so you won't have to define a data type for it. That means that, you are not making changes to the conceptual scheme of your database.
Considering that your table is implemented correctly, the SQL query you would need to give you the desirable result would be:
SELECT * FROM repairshop_reservations
WHERE date = "11/06/2017 20:00:00";
You use the WHERE clause, to filter your record and get an output with a
specified condition. In plain English, what you want to do is:
Select and print for me, every column from the repairshop_reservations table, that has listed date as "11/06/2017 20:00:00"
i have an events table having start date and end date I am trying retrieve all the records by giving a date that is between start and end dates.
eg :
SELECT *
FROM `events`
WHERE '2017-01-29' BETWEEN start_date='2017-01-28'
AND end_date='2017-01-31'
but response is syntax error can any one help me to finish the query
Just list the columns.
WHERE '2017-01-29' BETWEEN start_date AND end_date
The values come from the table, you don't put them into the query.
According to mysql documentation (https://dev.mysql.com/doc/refman/5.7/en/comparison-operators.html#operator_between) the syntax for BETWEN is
expr BETWEEN min AND max
it is not
expr BETWEEN blabla=min AND stuff=max
Also, it is rather pointless to be using constants in all three expressions, because in this case the result will be known in advance (either always TRUE or always FALSE) without having to consult the values in your table.
It is kind of hard to give you an example without knowing the structure of your table, but what you probably want is something like
WHERE '2017-01-29' BETWEEN start_date
AND end_date
(assuming start_date and end_date are columns in your table)
or something like
WHERE some_column BETWEEN '2017-01-28'
AND '2017-01-31'
(assuming some_column is a column in your table.)
I believe you're trying to find all the rows where a date is 2017-01-29, and so, your query could be:
SELECT *
FROM `events`
WHERE
date = '2017-01-29';
If, however, you want all rows with date between 2017-01-28 and 2017-01-31, then you could do:
SELECT *
FROM `events`
WHERE
date BETWEEN '2017-01-28' AND '2017-01-31';
Instead of putting 2017-01-29 before WHERE, put the name of the field you want to filter by date, such as EventDate (or whatever your field is named).
I am using two date time parameters in the report. When I use the same parameters in the query, no results are shown. Moreover if I use date parameters then the results are shown but not all records are shown.
I also executed the same query (with date time) in MySQL and the results are shown, I think there is no mistake in the query.
I tried many things. The query is some what like :
SELECT * FROM abc WHERE datetime BETWEEN
date_format($P{fromdate}, '%d-%c-%y 00:00:00')
AND date_format($P{todate}, '%d-%c-%y 23:59:59')
Try without data_format function to check whether error in query or in parameters.
SELECT *
FROM abc WHERE datetime BETWEEN
$P{fromdate} AND $P{todate}
I am working with a MySQL database where dates are stored as varchar like this:
'2013-01-31' in column cl_223
I need to select only records from 2013 so I tried:
SELECT ..
FROM ....
Where cl_223 Like '2013'
But that does not seem to work.
Thanks for all help!
You must add % as a wildcard :
SELECT ..
FROM ....
WHERE cl_223 LIKE '2013%'
Storing a datettime value in a varchar column complicates some functionality on date time operations. But of course you can select your values writing such a query as follow
SELECT * FROM table_name WHERE cl_223 LIKE '2013%'
But if you don't have any performance issue you can convert the varchar column to a datetime value and write stronger typed query like this:
SELECT * FROM table_name WHERE STR_TO_DATE(cl_223,'%Y-%m-%d2') BETWEEN '2013-01-01' AND '2013-12-31'
But if you need a date time value as a date time in your process you'd better store it in a datetime column instead of a varchar column.
The query should be
SELECT ..
FROM ....
Where cl_223 Like '2013%'
However, the better solution would be to store the dates as DATE data types. If the dates in that column are always used in the format they're in now, the change would be backwards compatible. It would also allow for easier processing of the date values.
In MySQL, I need to write a query (if possible) that finds all rows of a table where the date_created is the same as last_updated. The rub is that I need to ignore the time. Basically, I'm looking for user rows that were created and activated the same day (we don't store an activation date). So presumably the dates would be the same but the times may be different.
You could use the DATE() function, which returns only the date portion of a datetime value. This allows you to compare just the date portion of the values:
SELECT * FROM table_name
WHERE DATE(date_created) = DATE(last_updated)
The timezone may be relevant here. So you may want to cast the datetime values to the user's timezone prior to using the DATE() function, using CONVERT_TZ().
Try this:
SELECT *
FROM table_name
WHERE DATE_FORMAT(date_created, '%Y-%m-%d') = DATE_FORMAT(last_updated, '%Y-%m-%d')
not pretty but works:
SELECT *
FROM table_name
WHERE day(date_created) = day(last_updated) and
month(date_created) = month(last_updated) and
year(date_created) = year(last_updated)