i want to create a table on sqlite with one field as DateTime (YYYY-MM-DD) , how i can create it?
i'm trying with:
create table test (_date datetime);
but i'm not sure if the datatype is correct 'cause i can do this:
create table test (_date nyanType);
and no error occours
SQLite is rather unique in that its columns are not statically typed. You can technically store a string in a column that was created as an integer column.
If you check out the SQlite Documentation for types, you'll see that SQLite dosn't have a date type, but it exposes date and time functions that are suitable for manipulating dates that are stored as TEXT, REAL or INTEGER. You should use those instead.
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In Sqlite I want to extract the date and time portions of a DateTime field separately in a view and return them also as a datetime, not strings. I've tried Cast, Date(), datetime(), but they all return strings.
I've read the SQLite documentation and understand how there is not an actual Date data type. Yet a Table field defined as DateTime is able to be parsed as a Date by an Excel query, but calculations on that field are not. I'm trying to do all data prep in the database view.
My data has the following field taken directly from the table definition:
LastModifiedDate datetime
I want the date (without time) to have the same DateTime data type as LastModifiedDate, not Text, because I use this view in many spreadsheets. I can apply Excel Date functions and formatting to LastModifiedDate field directly as returned from the ODBC query to Excel, and want to do the same to the Date-only part. I don't want to have to put a string-to-date conversion in every spreadsheet when I know it can get the date natively from Sqlite in LastModifiedDate.
SELECT LastModifiedDate,
date(LastModifiedDate) as Datepart,
cast(LastModifiedDate as numeric) as Date2
FROM Transactions
LastModifiedDate Datepart Date2
2019-07-28 18:22:38.9165394 2019-07-28 2019
LastModifiedDate in the above query is interpreted in Excel as a date to which date formats and date functions can be applied with no further processing required. Datepart above is returned as Text to Excel, and I can't apply date functions and formats without further pre-processing in Excel. I would like Datepart to be interpreted a date in Excel just as LastModifiedDate is.
I'm looking at the ch-werner.de sqliteodbc-0.9998. It will return an ODBC TIMESTAMP type only if the column decltype starts with timestamp or datetime. It returns ODBC TIME only for decltypes starting with time and ODBC DATE only for decltypes starting with date.
sqlite3 provides this decltype only for result table columns that are direct database column references. So if your SELECT statement has some expression that is more than a plain column reference, the decltype is lost. sqlite3 works like this at least up to version 3.39.0. It is documented.
The CAST expression converts the value of given expression to a storage classes by the determined affinity of the given declared type, but does not assign decltype to the result.
If you want to see the decltypes for query columns, you can use the sqlite3 cli and give it command .stats 2. Then it'll output the column declared types for each statement it executes.
If the decltype is found, the sqliteodbc-0.9998 will always parse string values into ODBC types. If DSN Option JDConv is enabled, it'll also parse floating point julianday values (whether provided as float or a string of a float) into ODBC types and when writing it'll write floating point into database.
If you can afford to change the schema, you can add a generated virtual column. This is cheap in storage, because data is not affected, but it costs when you query the column. This column can calculate other column into the values and decltypes you need for ODBC.
ALTER TABLE data ADD COLUMN
Datepart date AS (date(LastModifiedDate))
Then to get the Datepart, you simply query the column.
SELECT Datepart FROM data
I Am new to SQLite.I am trying to create table from my model class in which I have DATETIME field.when sqlite table creatd from This Class The DATETIME column creted of type bigint.I know the reason because SQLite doesn't support DATETIME
So what should I do to create Column Of type TEXT in SQLITE without Chnging DATETIME type in my model Class. I found some post regarding to this but don't get satisfactory solution.please help.Thanks
You can configure how DateTimes are stored in your connection string. Change the attribute DateTimeFormat to either "ISO8601" or "CurrentCulture".
But: I would not recommend to do that. If you ever want to sort by a datetime or you want to filter rows (give me all entries from the last 2 weeks) then the bigint approach is the most efficient one. While ISO8601 datetime strings are sortable, that is most likely not the case with localised CurrentCulture strings. So if you really want human-readable strings in your database then choose the ISO version.
I imported a SQLite DB into MS-Access using ODBC and it was successful except for one column. One of the columns in SQLite DB was of 'Integer' datatype but it contained a string since datatypes are flexible in SQLite. But in the imported MS-Access DB, the column corresponding to that particular datatype is blank. I assume that the Access DB was expecting a integer datatype and not accepting a string. The following is the table structure:
CREATE TABLE test
(
num INTEGER,
name TEXT,
script INTEGER NOT NULL
);
I have problem with the column 'script'. I am not allowed to change the datatype here so is there any solution that I can workout in Access?
You can create a SQLite VIEW named "forimport" to CAST the troublesome column as TEXT
CREATE VIEW forimport AS SELECT num, name, CAST(script AS TEXT) AS script FROM test;
and then import the view (instead of the table) from SQLite into Access
I use sqlite3 C/C++ API to retrieve rows from a table using SELECT query. I don't see any sqlite3_column_timestamp() to retrieve a timestamp column value after sqlite3_step().. How to get timestamp values ?
SQLite does not have a special timestamp data type.
When you want to use any of SQLite's date and time functions, you have to store timestamps in one of the formats supported by them, i.e., a string like YYYY-MM-DD HH:MM:SS or HH:MM:SS, a julian date number, or a Unix timestamp number.
You can declare a table column type as DATETIME, but SQLite will just ignore that type; SQLite always allows to put values of any type in any column. Such a declaration would be useful only as documentation.
The column/value accessors will only have types corresponding to the data types they support directly (NULL, INTEGER, REAL, TEXT, BLOB).
You would use the TEXT access to get/set the column value of dates.
There are some helper functions within SQL that they provide that let you to handle them in your queries.
I am not familiar with SQLite Manager, but I would assume that it is only reporting the data type that the table was declared with.
When parsing CREATE statements, sqlite understands the intention of many well supported datatypes and automatically maps them to what is appropriate for its internal storage structure. VARCHAR would be mapped to TEXT, for instance. I assume the column was declared DATETIME and sqlite just internally mapped it to TEXT.
I have an sqlite database which currently holds an integer field called Year which currently only stores the year. In future versions I want to store a full date and time.
I updated my table to include a FullDate field using alter table.
> ALTER TABLE Files ADD COLUMN UploadDate DATETIME DEFAULT 0;
Next, I want to migrate all the existing year fields to the new field. So I'm looking for something like:
> UPDATE Files SET UploadDate = (DATETIME('%Y-%m-%d', Year, 1, 1));
Unfortunately this doesn't seem to work as the result is empty. I also tried the date and strftime functions but they either result in incorrect data or empty data.
What's the proper way to update a DATETIME field with existing data in the same table?
The DATE and DATETIME functions don't have a format parameter.
For more: http://sqlite.org/lang_datefunc.html
The main catch is that SQLite does not have any date or time types, so that you might as well populate your field with:
UPDATE Files SET UploadDate = Year || '-01-01';
And that will do the exact same thing. Dates are not stored as typed, but can be evaluated as such against the date and time functions.