I'd like to be able to do something like this:
insert into mydb.mytable (updatetimestamp) values (#1/15/2012 01:03:00#)
...or...
select * from mydb.mytable where updatetimestamp = #1/15/2012 01:03:00#
Using literals wouldn't required the longwindedness of casting and whatnot since it would immediately interpret the expression as a DATE or TIMESTAMP.
Does Teradata support this type of syntax?
Yes, Teradata supports the ANSI format for dates and timestamps. Reference: http://www.teradataforum.com/l070316a.htm
For example:
INSERT
INTO mydb.mytable (updatetimestamp)
VALUES (TIMESTAMP '2012-01-15 01:03:00');
Or:
SELECT *
FROM mydb.mytable
WHERE updatedate = DATE '2012-01-15';
Related
I have value of column
datecolumn -> 2021-04-22T00:00:00.000
I want select using condition where like below:
SELECT * FROM 'tblDOISOAT' where datecolumn = strftime('%Y-%m-%d %H:%M:%S','2021-04-22 00:00:00')
I not get được value and i me met error 'Error: near "=": syntax error'. please help me
You have a typo, but your code works.
--------
dt
--------
2021-04-22T00:00:00.000
2021-04-23T01:00:00.000
--------
select strftime('%Y-%m-%dT%H:%M:%S.000', '2021-04-22 00:00:00') as 'datecode'
returns 2021-04-22T00:00:00.000
The query:
select dt from 't' where dt= strftime('%Y-%m-%dT%H:%M:%S.000', '2021-04-22 00:00:00')
returns the expected result: 2021-04-22T00:00:00.000
You forgot to include the correct formatting including T and .000 at the end.
remember that SQLite does not have a datetime data structure by default. You can read about SQLite data types here
If you are storing date/times as ISO-8601 text, you don't need to call strftime() to make comparisons. Just compare the 2 values:
select * from t1 where datecol = '2021-04-22T00:00:00.000';
The whole point of ISO-8601 strings is to make sure that date/time values compare lexicographically the same as temporally.
I have the following query working in pure SQL on SQLite but do not know how to convert it to pyDAL:
SELECT * FROM buy WHERE date('now','-2 days') < timestamp;
The buy table schema is:
CREATE TABLE "buy"(
"id" INTEGER PRIMARY KEY AUTOINCREMENT,
"order_id" CHAR(512),
"market" CHAR(512),
"purchase_price" DOUBLE,
"selling_price" DOUBLE,
"amount" DOUBLE
, "timestamp" TIMESTAMP, "config_file" CHAR(512));
Instead of using the SQLite date function, you can create the comparison date in Python:
import datetime
cutoff_time = datetime.datetime.now() - datetime.timedelta(2)
rows = db(db.buy.timestamp > cutoff_time).select()
Alternatively, you can also pass a raw SQL string as the query:
rows = db('buy.timestamp > date("now", "-2 days")').select(db.buy.ALL)
Note, in this case, because the query within db() is simply a string, the DAL will not know which table is being selected, so it is necessary to explicitly specify the fields in the .select() (alternatively, you could add a dummy query that selects all records, such as (db.buy.id != None)).
Context is Teradata SQL Assistant
Successfully created the following table:
CREATE VOLATILE TABLE RSN_WEEKLY_TMP, NO LOG
(
EXPLICIT_DATE DATE FORMAT 'MM/DD/YYYY'
)
PRIMARY INDEX (EXPLICIT_DATE)
ON COMMIT PRESERVE ROWS;
1) The following INSERT works successfully:
INSERT INTO JOCOOPER.RSN_WEEKLY_TMP (EXPLICIT_DATE) VALUES (CURRENT_DATE);
2) The following INSERT does not work and returns with Error:INSERT Failed [26665] Invalid date.
INSERT INTO JOCOOPER.RSN_WEEKLY_TMP (EXPLICIT_DATE) VALUES (02/02/2016);
3) However, if I use a string 'date value' and CAST it as a Date it works.
INSERT INTO JOCOOPER.RSN_WEEKLY_TMP (EXPLICIT_DATE) VALUES (CAST('02/03/2016' AS DATE FORMAT 'MM/DD/YYYY') );
I need to know how to make example #2 work? Please Advise?
02/02/2016 is an INTEGER calculation, dividing 2 by 2 by 2016, results in zero, of course this is not a valid date.
CAST('02/03/2016' AS DATE FORMAT 'MM/DD/YYYY') works because it tells the parser how to convert the string to a DATE.
The only recommended (and the shortest) way is a Standard SQL DATE literal:
DATE '2016-02-03'
You never need to think about formats because there's only one: YYYY-MM-DD
Actually, this format works too
insert into table_name (datecol) select '2015/12/31';
In your example:
CREATE VOLATILE TABLE RSN_WEEKLY_TMP, NO LOG
(
--EXPLICIT_DATE DATE FORMAT 'MM/DD/YYYY'
EXPLICIT_DATE DATE
)
PRIMARY INDEX (EXPLICIT_DATE)
ON COMMIT PRESERVE ROWS;
INSERT INTO JOCOOPER.RSN_WEEKLY_TMP (EXPLICIT_DATE) select '2016/02/02';
When defining a relation, I want to update an attribute to the timestamp at insert. For example, a working table that I have right now
CREATE TABLE t1(
id INTEGER PRIMARY KEY AUTOINCREMENT,
time TIMESTAMP
DEFAULT CURRENT_TIMESTAMP,
txt TEXT);
This is updating a timestamp on insert, for example, insert into t1 (txt) values ('hello') adds the row 1|2012-07-19 08:07:20|hello|. However, I want to have this date formatted in unixepoch format.
I read the docs but this wasn't clear. For example, I modified the table relation to time TIMESTAMP DEFAULT DATETIME('now','unixepoch') but I get an error. Here, as in the docs, now was my time string and unixepoch was the modifier but it didn't work. Could someone help me how to format it as a unixepoch timestamp?
Use strftime:
sqlite> select strftime('%s', 'now');
1342685993
Use it in CREATE TABLE like this:
sqlite> create table t1 (
...> id integer primary key,
...> time timestamp default (strftime('%s', 'now')),
...> txt text);
sqlite> insert into t1 (txt) values ('foo');
sqlite> insert into t1 (txt) values ('bar');
sqlite> insert into t1 (txt) values ('baz');
sqlite> select * from t1;
1|1342686319|foo
2|1342686321|bar
3|1342686323|baz
See https://www.sqlite.org/lang_createtable.html#tablecoldef
If the default value of a column is an expression in parentheses, then the expression is evaluated once for each row inserted and the results used in the new row.
Note 'timestamp' is not a data type known to SQLite (see list here). The default value generated by strftime() would actually be stored as Text.
If it is important to store the value as a number instead of as a string, declare the field as an Integer and add a CAST() into the mix, like so:
create table t1(
...
ts_field integer(4) default (cast(strftime('%s','now') as int)),
...
);
Indeed strftime, which can also be used like so:
SELECT strftime('%s', timestamp) as timestamp FROM ... ;
Gives you:
1454521888
'timestamp' table column can be a text field even, using the current_timestamp as DEFAULT.
Without strftime:
SELECT timestamp FROM ... ;
Gives you:
2016-02-03 17:51:28
Is there a way to create a table in sqlite3 that has a datetime column that defaults to 'now'?
The following statement returns a syntax error:
create table tbl1(id int primary key, dt datetime default datetime('now'));
Update: Here's the correct ddl courtesy of Sky Sanders:
create table tbl1(id int primary key, dt datetime default current_timestamp);
Try this:
create table tbl1(id int primary key, dt datetime default current_timestamp);
Background:
The DEFAULT constraint specifies a
default value to use when doing an
INSERT. The value may be NULL, a
string constant, a number, or a
constant expression enclosed in
parentheses. The default value may
also be one of the special
case-independant keywords
CURRENT_TIME, CURRENT_DATE or
CURRENT_TIMESTAMP. If the value is
NULL, a string constant or number, it
is inserted into the column whenever
an INSERT statement that does not
specify a value for the column is
executed. If the value is
CURRENT_TIME, CURRENT_DATE or
CURRENT_TIMESTAMP, then the current
UTC date and/or time is inserted into
the columns. For CURRENT_TIME, the
format is HH:MM:SS. For CURRENT_DATE,
YYYY-MM-DD. The format for
CURRENT_TIMESTAMP is "YYYY-MM-DD
HH:MM:SS".
From http://www.sqlite.org/lang_createtable.html
... default (datetime(current_timestamp))
The expression following default must be in parentheses. This form is useful if you want to perform date arithmetic using SQLite date and time functions or modifiers.
CURRENT_TIMESTAMP is a literal-value just like 'mystring'
column-constraint:
literal-value:
you can use the following query for using current date value in your table
create table tablename (date_field_name Created_on default CURRENT_DATE);