I have been trying to format the date and time in the CREATE command (to apply for cases where user does not enter any value for date/time). According to the manual, there are the TO_DATE and TO_TIMESTAMP format elements. How do I fix my SQL statement?
http://hsqldb.org/doc/guide/builtinfunctions-chapt.html#N142F5
CREATE TABLE test1(
Id INTEGER GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
"Date In" DATE DEFAULT TO_TIMESTAMP(CURRENT_DATE, 'DD/MM/YYYY'),
"Time In" TIME DEFAULT TO_TIMESTAMP(CURRENT_TIME,'HH:MM')
);
I tried with TO_CHAR but still return an error.
https://wiki.documentfoundation.org/Faq/Base/HSQLFunctions
DATE, TIMESTAMP or TIME values do not have "a format". They are stored in a binary way and formatted when they are displayed. So you can't apply "a format" to a DATE column. Additionally, calling to_timestamp() on a value that is a date makes no sense. to_timestamp() is used to convert a string (character) value to a date (or timestamp).
Just define both columns without (wrongly) applying a conversion from a string to a timestamp:
CREATE TABLE test1(
Id INTEGER GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
"Date In" DATE DEFAULT CURRENT_DATE,
"Time In" TIME DEFAULT CURRENT_TIME
);
Given the name of the two columns, I think it would make more sense to store that in a single timestamp column:
CREATE TABLE test1(
Id INTEGER GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
"Date Time In" TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);
Related
I have the following table:
create table booking (
identifier integer not null primary key,
room uuid not null,
start_time time without time zone not null,
end_time time without time zone not null
);
I want to create an exclude constraint to enforce that there are no overlapping appointments for the same room.
I tried the following:
alter table booking add constraint overlapping_times
exclude using gist
(
cast(room as text) with =,
period(start_time, end_time) with &&)
);
This has two problems:
Casting room to text is not enough, it gives: ERROR: data type text has no default operator class for access method "gist". I know in v10 there is btree_gist, but I am using v9.5 and v9.6, so I have to manually cast the uuid to a text afaik.
period(...) is wrong, but I have no idea how to construct a range of time without time zone type.
After installing btree_gist, you can do the following:
create type timerange as range (subtype = time);
alter table booking add constraint overlapping_times
exclude using gist
(
(room::text) with =,
timerange(start_time, end_time) with &&
);
If you want an expression in the constraint you need to put that into parentheses. So either (room::text) or (cast(room as text))
Create table image_media_tracking (
image_rowid_src ROWID,
image_id NUMBER(6),
image_src BLOB,
image_time sysdate
);
As I mentioned in the comment, use date instead of sysdate.
Also if you want column to be sysdate by default, use
Create table image_media_tracking (
image_rowid_src ROWID,
image_id NUMBER(6),
image_src BLOB,
image_time date default sysdate
);
It seems you need the time instead of date so use use Datetime rather.
sysdate is not an Oracle datatype (it is the function that returns the current date and time).
You need date, or one of the other date time datatypes.
I have to create a table in H2 with primary key in yyyyMMddHHmmssSSS format.So that for every insert it automatically takes current date time in the mentioned format.
CREATE TABLE TEST_TABLE(ID BIGINT DEFAULT CURRENT_TIMESTAMP() PRIMARY KEY, NAME VARCHAR(255));
Problem is CURRENT_TIMESTAMP() format is yyyy-MM-dd HH:mm:ss.SSS.How can I get it in required format.
You can try this in the H2 console:
call formatdatetime(now(),'yyyyMMddHHmmssSSS');
This will give you a properly formatted string. Now you need to convert it to bigint.
call cast(formatdatetime(now(),'yyyyMMddHHmmssSSS') as bigint);
Last step: change your SQL accordingly...
CREATE TABLE TEST_TABLE(
ID BIGINT DEFAULT CAST(FORMATDATETIME(CURRENT_TIMESTAMP(), 'yyyyMMddHHmmssSSS') AS BIGINT) PRIMARY KEY,
NAME VARCHAR(255)
);
Tested on H2 1.3 and 1.4.
Word of caution: please use transactions and space your insertions...
I am writing a program to help me keep track of my day to day life, and I want one of the fields to be a "date" field that will automatically update. What specifically do I do in SQLITE 3? Something like....
create table day_to_day(
date field
miles_ran INTEGER
food_eaten TEXT
)
How about:
CREATE TABLE day_to_day(
id INTEGER PRIMARY KEY AUTOINCREMENT,
t TIMESTAMP DEFAULT CURRENT_TIMESTAMP
miles_ran INTEGER
food_eaten TEXT
);
which would give you a column called t with the type TIMESTAMP, as a alternative you could also use this:
CREATE TABLE day_to_day(
id INTEGER PRIMARY KEY AUTOINCREMENT,
t DATE DEFAULT (datetime('now','localtime')),
miles_ran INTEGER
food_eaten TEXT
);
Maybe you can use this :
CREATE TABLE table_test (
...
date TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);
or
CREATE TABLE table_test (
...
date DATE DEFAULT (datetime('now','localtime')),
);
This is a good reference : sqlite database default time value 'now'
You can read what the docs have to say about it: SQLite datatypes, scroll to section 1.2.
The gist of it is, you can either use TEXT, REAL, or INTEGER, and then use the corresponding Date/Time function to access it.
I am creating some tables where I want to store the time when a record was created and when it was last updated. I thought I could have two timestamp fields where one would have the value CURRENT_TIMESTAMP and the other would have CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP. But I guess I can't do this because you can have only 1 timestamp field with a default value in a table?
How would you recommend I get and store the two times? Thanks!
A good way to create fields like 'created' and 'updated' is
CREATE TABLE `mytable` (
`id` INTEGER NOT NULL AUTO_INCREMENT PRIMARY KEY,
`created` TIMESTAMP DEFAULT '0000-00-00 00:00:00',
`updated` TIMESTAMP DEFAULT now() ON UPDATE now(),
`myfield` VARCHAR(255)
);
And its necessary to enter nulls into both columns during "insert":
INSERT INTO mytable (created,updated,myfield) VALUES (null,null,'blablabla');
And now, in all updates, the 'updated' field will have a new value with actual date.
UPDATE mytable SET myfield='blablablablu' WHERE myfield='blablabla';
Source : http://gusiev.com/2009/04/update-and-create-timestamps-with-mysql
As of MYSQL version 5.6.5 you can do this using DEFAULT and ON UPDATE. No triggers are needed.
ts_create TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
ts_update TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
You can have two columns of type timestamp in one table.
The following works for MySQL 5.0
create table t
(
id integer,
created_at timestamp default current_timestamp,
updated_at timestamp
);
I think you are confusing this with SQL Server (where timestamp is not really a "time stamp" and there is indeed a limit on a single "timestamp" column)
Edit: But you will need a trigger to update the update_at column each time the row is changed.
As far as I know, there's no workaround for that restriction. You'll need to manually set (at least) one of the timestamps, the easiest way is just add updated = NOW() to the UPDATE-query.
You'll need two columns: CREATE_TIME and UPDATE_TIME.
You might want to add CREATE_USER and UPDATE_USER.
Perhaps you'd want to have a 1:many relationship with name of column changed, old and new values.
It's all part of change data capture. You could have CDC tables that are updated using triggers.
I would leave the current timestamp the way you suggested and fill in the created_at field with current date on insert.