I'm sure this is quite simple, but I've been stuck on it for some time. How can I convert a varchar field (YYYYMM) to a date (MM/01/YY) in SQL?
Thanks.
Edit: I'm using Open Office Base (HSQL), not MySQL; sorry for the confusion.
Try the str_to_date and date_format functions. Something like:
select date_format( str_to_date( my_column, '%Y%c' ), '%c/01/%y' ) from my_table
try :
SELECT STR_TO_DATE(CONCAT(myDate,'01'),'%Y%m%d')
FROM myTable
Use STR_TO_DATE:
From mysql.com:
STR_TO_DATE(str,format)
This is the inverse of the DATE_FORMAT() function. It takes a string str and a format string format. STR_TO_DATE() returns a DATETIME value if the format string contains both date and time parts, or a DATE or TIME value if the string contains only date or time parts.
The date, time, or datetime values contained in str should be given in the format indicated by format. For the specifiers that can be used in format, see the DATE_FORMAT() function description. If str contains an illegal date, time, or datetime value, STR_TO_DATE() returns NULL. Starting from MySQL 5.0.3, an illegal value also produces a warning.
Range checking on the parts of date values is as described in Section 11.3.1, “The DATETIME, DATE, and TIMESTAMP Types”. This means, for example, that “zero” dates or dates with part values of 0 are allowed unless the SQL mode is set to disallow such values.
mysql> SELECT STR_TO_DATE('00/00/0000', '%m/%d/%Y');
-> '0000-00-00'
mysql> SELECT STR_TO_DATE('04/31/2004', '%m/%d/%Y');
-> '2004-04-31'
Get the year:
SUBSTRING(field FROM 2 FOR 2)
Get the month:
SUBSTRING(field FROM -2 FOR 2)
Compose the date:
CONCAT(SUBSTRING(field FROM -2 FOR 2), '/01/', SUBSTRING(field FROM 2 FOR 2))
This will convert from YYYYMM to MM/01/YY.
To be clear: if you're looking for method to convert some value of type Varchar/Text to value of type Date than solutions are:
using CAST function
CAST(LEFT('201205',4)||'-'||SUBSTRING('201205' FROM 5 FOR 6)||'-01' AS DATE)
starting from OpenOffice 3.4 (HSQLDB 2.x) new Oracle-like function TO_DATE supposed to be available
TO_DATE('201205','YYYYMM')
in addition to the written i can mention that you also can construct a string with ANSI/ISO 'YYYY-MM-DD' formatted representation of the date,- Base will acknowledge that and succesfully convert it to the Date type if necessary (e.g. INSERTing in Date typed column etc.)
Here is doc's on HyperSQL and highly recommended OO Base guide by Andrew Pitonyak
Related
I need to filter by month in Sqlite, but the STRFTIME function returns Null.
The dates seem to be in a standard format.
SELECT arrival_date a,
departure_date d,
strftime('%m', arrival_date) m
FROM table
Returns (for example):
13/02/2015, 15/02/2015, Null
Is there any way to work around this?
strftime(), and all other sqlite date and time functions, will return null if given an argument in a format that they don't understand. DD/MM/YYYY formatted dates like 13/02/2015 are not an understood format. The complete list is in the documentation, but if storing just a date as a string, YYYY-MM-DD is what you need to use.
The strftime function for SQLite is intended to be used to parse a text date, perform some manipulation (e.g. adding some days), and then returning an output date string. If you just want to extract the numerical month component, then use substr:
SELECT
arrival_date a,
departure_date d,
substr(arrival_date, 4, 2) m
FROM table;
My table in hive has a filed of date in the format of '2016/06/01'. but i find that it is not in harmory with the format of '2016-06-01'.
They can not compare for instance.
Both of them are string .
So I want to know how to make them in harmory and can compare them. Or on the other hand, how to change the '2016/06/01' to '2016-06-01' so that them can compare.
Many thanks.
To convert date string from one format to another you have to use two date function of hive
unix_timestamp(string date, string pattern) convert time string
with given pattern to unix time stamp (in seconds), return 0 if
fail.
from_unixtime(bigint unixtime[, string format]) converts the
number of seconds from unix epoch (1970-01-01 00:00:00 UTC) to a
string representing the timestamp of that moment in the current
system time zone.
Using above two function you can achieve your desired result.
The sample input and output can be seen from below image:
The final query is
select from_unixtime(unix_timestamp('2016/06/01','yyyy/MM/dd'),'yyyy-MM-dd') from table1;
where table1 is the table name present in my hive database.
I hope this help you!!!
Let's say you have a column 'birth_day' in your table which is in your format,
you should use the following query to convert birth_day into the required format.
date_Format(birth_day, 'yyyy-MM-dd')
You can use it in a query in the following way
select * from yourtable
where
date_Format(birth_day, 'yyyy-MM-dd') = '2019-04-16';
Use :
unix_timestamp(DATE_COLUMN, string pattern)
The above command would help convert the date to unix timestamp format which you may format as you want using the Simple Date Function.
Date Function
cast(to_date(from_unixtime(unix_timestamp(yourdate , 'MM-dd-yyyy'))) as date)
here is my solution (for string to real Date type):
select to_date(replace('2000/01/01', '/', '-')) as dt ;
ps:to_date() returns Date type, this feature needs Hive 2.1+; before 2.1, it returns String.
ps2: hive to_date() function or date_format() function , or even cast() function, cannot regonise the 'yyyy/MM/dd' or 'yyyymmdd' format, which I think is so sad, and make me a little crazy.
I have a question regarding SQL dates.
The table I am working with has a date field in the following format: "22-SEP-08". The field is a date column.
I am trying to figure out how to output records from 1/1/2000 to present day.
The code below is not filtering the date field:
Select distinct entity.lt_date
from feed.entitytable entity
where entity.lt_date >= '2000-01-01'
Any help regarding this issue is much appreciated. Thanks!
Edit: I am using Oracle SQL Developer to write my code.
DATEs do not have "a format". Any format you see is applied by the application displaying the date value.
You can either change the configuration of SQL Developer to display dates in a different format, or you can use to_char() to format the date the way you want.
The reason your statement does not work, is most probably because of the implicit data type conversion that you are relying on.
'2000-01-01' is a string value, not a date. And the string is converted using the NLS settings of your session. Given the fact that you see dates displayed as DD-MON-YY means that that is the format that is used by the evil implicit data type conversion. You should supply date values always as real date literals.
There are two ways of specifying a real date literal. The first is ANSI SQL and simple uses the keyword DATE in front of an ISO formatted string:
where entity.lt_date >= DATE '2000-01-01'
Note the DATE keyword in front of the string, wich makes it a real date literal not a string expression.
The other option is to use to_date() to convert a character value into a date:
where entity.lt_date >= to_date('2000-01-01', 'yyyy-mm-dd');
More details about specifying date literals can be found in the manual:
Date literals
to_date function
My guess is the data type isn't a Date. Just in case its a char type, try to convert it using the Oracle TO_DATE() function. The Oracle documentation below should help you with parameters.
http://docs.oracle.com/cd/B19306_01/server.102/b14200/functions183.htm
An implicit datatype conversion bites once again.
You're right. The predicate is not doing the comparison you are expecting,
Oracle is performing an implicit datatype conversion, from DATE to VARCHAR, so that it can do a comparison to the string literal.
If lt_date column is DATE datatype, then Oracle is seeing your where clause:
where entity.lt_date >= '2000-01-01'
Oracle is actually seeing it as if it's written like this:
where TO_CHAR(entity.lt_date) >= '2000-01-01'
And that's where the "format" problem comes in. The column itself does not have a "format". Because the second argument to the TO_CHAR function is not supplied, Oracle is using the value of the NLS_DATE_FORMAT parameter (from your session). And that's probably set to DD-MON-YY. Which is why that's the "format" you're seeing when you a run a SELECT statement in SQL*Plus. Because the DATE value is (again) being run through a TO_CHAR function to get a string that can be displayed.
To get the "filtering" you want, don't do a comparison to a string literal. Instead, do the comparison to an expression that has DATE datatype.
You can use the Oracle TO_DATE function. And you don't want to rely on setting of NLS_DATE_FORMAT, explicitly specify the format model as the second argument to the function. For example:
DO THIS
where entity.lt_date >= TO_DATE('2000-01-01','YYYY-MM-DD')
DON'T DO THIS
It's also possible to specify the format model as the second argument to the TO_CHAR function.
where TO_CHAR(entity.lt_date,'YYYY-MM-DD') >= '2001-01-01'
But you don't want to do that because that's going to force Oracle to evaluate that expression on the left side for every flipping row in the table, so it has a string value to do the comparison. (That's true unless someone created a function-based index for you.) If you do the comparison on the bare column, using the TO_DATE on the literal side, Oracle can make effective use of an appropriate index (with lt_date as the leading column) to satisfy the predicate.
I want to create a table in Oracle 10g and I want to specify the date format for my date column. If I use the below syntax:
create table datetest(
........
startdate date);
Then the date column will accept the date format DD-MON-YY which I dont want.
I want the syntax for my date column to be MM-DD-YYYY
Please let me know how to proceed with this.
Regards,
A DATE has no inherent format. It is not simply a string that happens to represent a date. Oracle has its own internal format for storing date values.
Formats come into play when actual date values need to be converted into strings or vice versa, which of course happens a lot since interactively we write dates out as strings.
The default date format for your database is determined by the settings NLS_DATE_FORMAT, which you probably have set to DD-MON-YYYY (which I believe is the default setting for American English locales). You can change this at the database level or for a single session for convenience, but in general it is safer programming practice to be explicit so that you don't get errors or, worse, wrong results if your code is run in a different environment.
The simplest way to specify a date value unambiguously is a date literal, which is the word 'date' followed by a string representing the date in YYYY-MM-DD format, e.g. date '2012-11-13'. The Oracle parser directly translates this into the corresponding internal date value.
If you want to use a different format, then I recommend explicitly using TO_CHAR/TO_DATE with your desired format model in your code. Examples:
INSERT INTO my_table (my_date) VALUES ( TO_DATE( '11-13-2012', 'MM-DD-YYYY' ) );
SELECT TO_CHAR( my_date, 'MM-DD-YYYY' ) FROM my_table;
dates rdo not have a format like you're suggesting. they are stored internally as a 7 byte number. to format the date when selecting, please use TO_CHAR(yourdatefield, 'format')
where formats are all shown here: http://docs.oracle.com/cd/B19306_01/server.102/b14200/sql_elements004.htm#i34924
eg to_char(startdate, 'mm-dd-yyyy')
Is there a way to convert a date to a string in Sqlite? For example I am trying to get the min date in Sqlite:
SELECT MIN(StartDate) AS MinDate FROM TableName
I know in SQL Server I would use the SQL below to accomplish what I am trying to do:
SELECT CONVERT(VARCHAR(10), MIN(StartDate), 101) AS MinDate FROM TableName
Thanks!
SQLite doesn't have a date type. What CURRENT_TIMESTAMP actually returns is a string in the format YYYY-MM-DD HH:MM:SS. The date/time formatting/calculation functions accept strings in this format, or alternatively, numbers, which are interpreted as Julian dates unless you use the 'unixepoch' modifier.
So, "converting a date to a string" depends on how you're storing your dates:
If you're storing them as Julian dates, use DATE(YourDateColumn).
If you're storing them as Unix times, use DATE(YourDateColumn, 'unixepoch').
If you're storing them as ISO 8601 strings, then, well you don't have to do anything. Unless you want a string in a different format, in which case you should use the STRFTIME function.
If you're storing them as some other string format, you really should consider using one of the supported formats so you can use the date/time functions.
In all three date formats, chronological order is the same as lexicographical order, so the MIN function works as expected.
try this!!
SELECT * FROM Table WHERE strftime('%Y-%m-%d',CreatedAt) BETWEEN '2014-10-07' AND '2014-10-17'
Try this:
SELECT MIN(DATE('your-date-here')) as MinDate FROM TableName
And make sure your-date-here follows a well understood format by SQLite (See the Time String. section in the documentation)