How to compare one field to another using LIKE - sql

I want to so something like the following:
SELECT * FROM TABLE1
WHERE DATE1 LIKE DATE2 + '%'
However, when I try this I get the following error:
"5407: Invalid operation for DateTime or Interval"
I am working in Terdata SQL Assistant

You can't use like to compare dates, like is to compare string (varchar), then you can cast this dates to varchar or better way is cast both dates to the same format, for example:
SELECT * FROM TABLE1
WHERE convert(varchar, DATE1, 103) = convert(varchar, DATE2, 103)
This way cast dates to format: DD/MM/YYYY
If you wanna cast to another formats I let you a link that explain more types: https://www.mssqltips.com/sqlservertip/1145/date-and-time-conversions-using-sql-server/

You could potentially just format the dates the same way to compare them.
WHERE FORMAT(DATE1, 'dd/mm/yyyy') = FORMAT(DATE2, 'dd/mm/yyyy')

date2 is less than 1 day later
where datediff(d,date1,date2) < 1
Since your using like ... you could mean within a day before or after.
abs(datediff(d,date1,date2)) < 1

Related

Why does my query return records which doesn't meet the where clause conditions?

I have written a query which returns records with dates that are actually older than the mentioned date.
Declare #DateFrom date
Set #DateFrom= '02/Oct/2019'
SELECT 1, Convert(varchar(11), AppliedDateTime, 106)
FROM [MC_Tenders].[dbo].[AppliedWorks]
Where
Convert(varchar, AppliedDateTime,106) >= Convert(varchar, #DateFrom,106)
Applied dates are saved in table as datetime e.g. 2017-04-25 15:51:25.257
You are doing the comparison as strings rather than dates. Remove the conversion:
SELECT 1, Convert(varchar(11), AppliedDateTime, 106)
FROM [MC_Tenders].[dbo].[AppliedWorks]
WHERE AppliedDateTime >= #DateFrom;
Type 106 is dd mm yyyy. When you compare as strings, the strings are compared, not the dates. With format 106, the days are compared first, so: '18-10-2017' < '25-12-1900' because "1" < "2".
Just to finish Gordon Linoff's thought, your code should look something like this:
SELECT
1
, CAST(AppliedDateTime AS DATE) AS AppliedDate
FROM
[MC_Tenders].[dbo].[AppliedWorks]
WHERE
CAST(AppliedDateTime AS DATE) >= #DateFrom;
Edit: I'm assuming AppliedDateTime is actually stored as a datetime, or some data type other than DATE. The explicit CAST to the DATE type will strip out the time component and allow SQL to just compare the date component to your variable.

Converting string 'yyyy-mm-dd' to date

I want to select from table where date column is equal to specific date which I sending as a string in format 'yyyy-mm-dd'. I need to convert that string and than to compare if I have that date in my table.
For now I am doing this:
select *
FROM table
where CONVERT(char(10), date_column,126) = convert(char(10), '2016-10-28', 126)
date_column is a date type in table and I need to get it from table in this format 'yyyy-mm-dd' and because that I use 126 format. I am just not sure with the other part where I converting string which is already in that format and do I need to convert it because I don't know is it good to use this:
CONVERT(varchar(10), date_column,126) = '2016-10-28'
You don't need to convert the column as well. In fact, you better not convert the column, because using functions on columns prevents sql server from using any indexes that might help the query plan on that column.
Also, you are converting a string to char(10) - better just convert it to date:
where date_column = convert(date, '2016-10-28', 126)
Also, if you are using a datetime data type and not date, you need to check that the datetime value is between the date you pass to the next date.
You can convert string to date as follows using the CONVERT() function by giving a specific format of the input parameter
declare #date date
set #date = CONVERT(date, '2016-10-28', 126)
select #date
You can find the possible format parameter values for SQL Convert date function here
You do not need to do that. yyyy-MM-dd is the default format.
Please note that you need to take into account the time as well, if there's a timestamp in date_column. In that case you should write something like this
... WHERE date_column >= '2016-10-28 00:00:00' AND date_column < '2016-10-29 00:00:00'
... WHERE date_column BETWEEN '2016-10-28 00:00:00' and '2016-10-29 00:00:00'
As I just learned that (other than I thought) BETWEEN actually includes the end timestamp and thus is not equivalent to the above >= ... < approach.
This should use indexes properly as well.

Oracle use LIKE '%' on DATE

My table myTab has the column startDate, which has the datatype "DATE". The data in this column are stored like dd.mm.yyyy.
Now I'm trying to get data with this query:
SELECT * FROM myTab WHERE startDate like '%01.2015"
Somehow it doesn't work and I don't know why.
Hope someone can help.
To make a text search on the date you would have to convert the date to text.
It's more efficient if you calculate the first and last date for what you want to find and get everything between them. That way it's done as numeric comparisons instead of a text pattern match, and it can make use of an index if there is one:
SELECT * FROM myTab WHERE startDate >= DATE '2015-01-01' AND startDate < DATE '2015-02-01'
SELECT * FROM myTab WHERE TO_CHAR(startDate,'dd.mm.yyyy') LIKE '%01.2015'
If the field type is "DATE" then the value isn't stored as a string, it's a number managed by Oracle, so you have to convert it to a string:
SELECT * FROM myTab WHERE to_char(startDate, 'MM.YYYY') = '01.2015';
You can also use date ranges in SQL queries:
SELECT * FROM myTab
WHERE startDate
BETWEEN to_date('01.01.2015', 'DD.MM.YYYY')
AND to_date('31.01.2015', 'DD.MM.YYYY');
Regarding you actual question "Somehow it doesn't work and I don't know why."
Oracle make an implicit conversion from DATE to VARHCAR2, however it uses the default NLS_DATE_FORMAT which is probably different to what you use in your query.
The data in this column are stored like dd.mm.yyyy.
Oracle does not store date in the format you see. It stores it internally in proprietary format in 7 bytes with each byte storing different components of the datetime value.
WHERE startDate like '%01.2015"
You are comparing a DATE with a STRING, which is pointless.
From performance point of view, you should use a date range condition so that if there is any regular INDEX on the date column, it would be used.
SELECT * FROM table_name WHERE date_column BETWEEN DATE '2015-01-01' AND DATE '2015-02-01'
To understand why a Date range condition is better in terms of performance, have a look at my answer here.
I solved my problem that way. Thank you for suggestions for improvements. Example in C#.
string dd, mm, aa, trc, data;
dd = nData.Text.Substring(0, 2);
mm = nData.Text.Substring(3, 2);
aa = nData.Text.Substring(6, 4);
trc = "-";
data = aa + trc + mm + trc + dd;
"Select * From bdPedidos Where Data Like '%" + data + "%'";
To provide a more detailed answer and address this https://stackoverflow.com/a/42429550/1267661 answer's issue.
In Oracle a column of type "date" is not a number nor a string, it's a "datetime" value with year, month, day, hour, minute and seconds.
The default time is always midnight "00:00:00"
The query:
Select * From bdPedidos Where Data Like '%" + data + "%'"
won't work in all circumstances because a date column is not a string, using "like" forces Oracle to do a conversion from date value to string value.
The string value may be year-month-day-time or month-day-year-time or day-month-year-time, that all depends how a particular Oracle instance has set the parameter NLS_DATE_FORMAT to show dates as strings.
The right way to cover all the possible times in a day is:
Select *
From bdPedidos
Where Data between to_date('" + data + " 00:00:00','yyyy-mm-dd hh24:mi:ss')
and to_date('" + data + " 23:59:59','yyyy-mm-dd hh24:mi:ss')
SELECT * FROM myTab WHERE startDate like '%-%-2015';
This will search for all dates in 2015. If this doesn't work, try:
SELECT * FROM myTab WHERE startDate like '%-%-15';

compare dates in SQL query

I would like to compare today's date with the dates I'm pulling from a DB and select entries accordingly. Those two formats do not match (I assume so) and I get an error. By the way, I am not sure what exact format myDate is stored in. Below is what I would essentially like to achieve.
WHERE (myDate > CURDATE())
you can format both the dates as below .
select * from mytable where convert(char(8), myDate,112) > convert(char(8),myDate,112)
code 112 will case them to be converted in YYYYMMDD format
select * from mytable where
convert(date, myDate) > convert(date,myDate)
in sql server.
or, if that does not work, try formatting the date with substring and then converting/casting/parsing.
select convert(date, (substring(myfield,9,2) + '/' + substring(myfield,6,2) + '/' + substring(myfield,1,4))) from mytable

Sybase date comparison - Correct format?

I'm pretty new to Sybase and am writing a query to return results after a specified date, and also before a specified date. MM/DD/YYYY format
At the moment im doing..
SELECT *
From aTable
WHERE afterDate >= 08/07/2013
AND beforeDate <= 08/08/2013
I'm getting records back, but as I'm a Sybase newbie, I want to be sure Sybase is interpreting these dates correctly..
Their online doc is pretty bad for basic explanations on things like this!
Anyone able to confirm if what I have works, or does it need some formatting round the dates?
You'll need to convert the dates into DATETIME and tell sybase what the format is to be sure.
According to this documentation the code for MM/DD/YYYY is 101, so something like this:
SELECT *
FROM aTable
WHERE afterDate >= CONVERT(DATETIME,'08/07/2013',101)
AND beforeDate <= CONVERT(DATETIME,'08/08/2013',101)
You can see the difference by running the following select statements:
SELECT CONVERT(DATETIME,'08/07/2013',101) --MM/DD/YYYY (2013-08-07 00:00:00.000)
SELECT CONVERT(DATETIME,'08/07/2013',103) --DD/MM/YYYY (2013-07-08 00:00:00.000)
For any date-time field in sybase, instead of going through the convert function, there is a more direct approach.
SELECT *
From aTable
WHERE afterDate >= '2013-08-07'
AND beforeDate <= '2013-08-08'
The date has to be in the form 'YYYY-MM-DD'
If you want to add a time, it can be included along with the date. The date and the time have to be separated by a T.
Any date time field can be directly used using the format 'YYYY-MM-DDTHH:MM:SS'
Using the functions is too lengthy. Noone needs a bazooka to shoot a squirrel! :)
CAST( '2000-10-31' AS DATE )
will convert from text to date format....
I am assuming that your two fields (afterDate and beforeDate) are in Date format.
Your example would be:
SELECT *
From aTable
WHERE afterDate >= CAST( '08/07/2013' AS DATE )
AND beforeDate <= CAST( '08/08/2013' AS DATE )
Also, usually (but not always) a date range is on the SAME field. As I said, that is not true all the time and you may have a good reason for that.
The best approach is to use the ANSI standard which does not require any conversion: yyyymmdd (you can also include hh:mm:ss) for instance:
DateField1 >= "20150101" and DateFile1 <= "20150102"
You should decide which Input-Strings the user is going to use as parameter and then convert them and concatenate them like you want, unless it is Datetime it is not important which initial format it had, you can use it in a between-condition.
E. g. the user is from Europe and uses "DD.MM.YY" and "hh:mm" as an input parameter, I would convert and concatenate like this:
WHERE dateCol between convert(DATETIME,
convert(char(11),
convert(DATETIME, '01.06.14', 4), 16) || ' ' || '00:00', 8)
AND convert(DATETIME,
convert(char(11),
convert(DATETIME, '01.07.14', 4), 16) || ' ' || '16:00', 8)