I'm creating a database and I want to create a Constraint Check that only allows to insert Dates that are after year 2000.
This is where i store dates:
CREATE TABLE User (
username varchar(20) NOT NULL,
birthdate DATE NOT NULL,
CONSTRAINT user_birthdate_ck CHECK (birthdate > 2000)
)
2000 is not a date, it's a number.
You need to specify a date in quotes using an unambiguous date format. Best to use 'YYYYMMDD'.
CREATE TABLE [User] (
username varchar(20) NOT NULL,
birthdate DATE NOT NULL,
CONSTRAINT user_birthdate_ck CHECK (birthdate > '20000101')
);
db<>fiddle
Assuming you actually wanted after the year 2000 then you probably want
CONSTRAINT user_birthdate_ck CHECK (birthdate >= '20010101')
Do not use > '20001231' if you have a time component as it won't be correct.
Change the year to a properly formed date as follows:
CONSTRAINT user_birthdate_ck CHECK (birthdate > '2000/12/31')
It would also be prudent to explicitly set the date format being used before the CREATE TABLE as follows:
SET DATEFORMAT ymd;
GO
BEWARE all the strings expression of dates showns in answers are not in the ISO SQL format and won't do the job under certain session parameters like language or some others, espcially mixed with non Transct SQL in a batch...
The only string format that never cause you any trouble is the SQL ISO long date format as :
'AAAA-MM-JJ'
Related
how to create date format yyyy-mm with postgresql11
CREATE TABLE public."ASSOL"
(
id integer NOT NULL,
"ind" character(50) ,
"s_R" character(50) ,
"R" character(50) ,
"th" character(50),
"C_O" character(50) ,
"ASSOL" numeric(11,3),
date date,
CONSTRAINT "ASSOL_pkey" PRIMARY KEY (id)
This is a variation of Kaushik's answer.
You should just use the date data type. There is no need to create another type for this. However, I would implement this use a check constraint:
CREATE TABLE public.ASSOL (
id serial primary key,
ind varchar(50) ,
s_R varchar(50) ,
R varchar(50) ,
th varchar(50),
C_O varchar(50) ,
ASSOL numeric(11,3),
yyyymm date,
constraint chk_assol_date check (date = date_trunc('month', date))
);
This only allows you to insert values that are the first day of the month. Other inserts will fail.
Additional notes:
Don't use double quotes when creating tables. You then have to refer to the columns/tables using double quotes, which just clutters queries. Your identifiers should be case-insensitive.
An integer primary key would normally be a serial column.
NOT NULL is redundant for a PRIMARY KEY column.
Use reasonable names for columns. If you want a column to represent a month, then yyyymm is more informative than date.
Postgres stores varchar() and char() in the same way, but for most databases, varchar() is preferred because trailing spaces actually occupy bytes on the data pages.
for year and month you can try like below
SELECT to_char(now(),'YYYY-MM') as year_month
year_month
2019-05
You cannot create a date datatype that stores only the year and month component. There's no such option available at the data type level.
If you want to to truncate the day component to default it to start of month, you may do it. This is as good as having only the month and year component as all the dates will have day = 1 and only the month and year would change as per the time of running insert.
For Eg:
create table t ( id int, col1 text,
"date" date default date_trunc('month',current_date) );
insert into t(id,col1) values ( 1, 'TEXT1');
select * from t
d col1 date
1 TEXT1 2019-05-01
If you do not want to store a default date, simply use the date_trunc('month,date) expression wherever needed, it could either be in group by or in a select query.
I want to save the date in format 'dd.mm.yyyy'. So I read there are different formats for a date in SQL (by the way I use Visual Studio and SQL Server).
I tried this code:
CREATE TABLE APP(
ID INT NOT NULL,
DT DATE FORMAT 'dd.mm.yyyy',
ADDRESS NVARCHAR (100) ,
PRIMARY KEY (ID)
);
But it returns the error:
Incorrect syntax near 'FORMAT'.
After that I want to use this code:
INSERT INTO APP (ID, DT)
VALUES ('1','22.12.2016')
You don't need to specify the format in the table definition as dates are stored in a binary format.
CREATE TABLE APP(
ID INT NOT NULL,
DT DATE,
ADDRESS NVARCHAR (100) ,
PRIMARY KEY (ID)
);
When you try to insert into that table however, the server will try to convert the string to a date before inserting it. This can be problematic as it is unable to tell if 12.11.2017 is the 12th of November or 11th of December. To figure this out it uses the localization settings of the user account that is performing the operation.
Often you will find that the account that is running the operation is set to USA format, month day then year (MDY), when what you want is day month year (DMY) format. One way to tell it what the sequence of the date's parts is to use the DATEFORMAT setting like this:
SET DATEFORMAT dmy;
INSERT INTO APP (ID, DT)
VALUES (1,'22.12.2016')
Another alternative is to cast the string to a date using the CONVERT function and tell it what the date format is. The formats have numeric codes like 104 for German format Like this:
INSERT INTO APP (ID, DT)
VALUES (2,CONVERT(date,'22.12.2016',104))
Dates are stored in an internal format. Formats only make sense for input and output.
In your case you want the date in a German format (104), so you can use:
select convert(varchar(255), dt, 104)
If you like, you can include the formatted date as a separate column:
CREATE TABLE APP (
ID INT NOT NULL,
DT DATE,
ADDRESS NVARCHAR(100),
DT_FORMATTED AS (convert(varchar(255), dt, 104)),
PRIMARY KEY (ID)
);
You can then refer to dt_formatted to get the string in the format you want.
Use this:
CREATE TABLE APP(
ID INT NOT NULL,
DT DATE ,
ADDRESS NVARCHAR (100) ,
PRIMARY KEY (ID)
);
Its default setting is yyyy-MM-dd.
No, it's not. There is no formatting information at all associated with the field.
The value is not formatted by the database. It's returned only as a point in time. Formatting that value into its textual representation is done by the application that is getting the data from the database.
So, there is nothing that you can do in the database to change how the date value is formatted. You have to change that where the data is displayed.
Dates are stored in an internal format.
Formats only make sense for input and output.
You can include the formatted date as a separate column:
SQL Server supports the date format. You have to use the below date format.
With century (yyyy) | Standard | Input/Output
103 | British/French | 103 = dd/mm/yyyy
CREATE TABLE [dbo].[Post]
(
[Id] INT IDENTITY (1, 1) NOT NULL,
[Name] VARCHAR(MAX) NULL,
[RowNo] INT NULL,
[ColNo] INT NULL,
[Deadline] (CONVERT(VARCHAR(255), dt, 103)), -- Include the formatted date as a separate column
CONSTRAINT [PK_KtoCo]
PRIMARY KEY CLUSTERED ([Id] ASC)
);
Use this.
CREATE TABLE:
CREATE TABLE EMP
(EID NUMBER(20),
ENAME VARCHAR2(20),
DT DATE,
SAL NUMBER(20));
INSERT INTO THE TABLE:
INSERT INTO EMP (EID,ENAME,DT,SAL) VALUES(01,'ABCDE','11.NOV.2011',10000);
O/P OF ABOVE TABLE:
SELECT * FROM EMP;
EID ENAME DT SAL
01 ABCDE 11-DEC-11 10000
Getting this error while trying to put a few inserts into a table.
Getting an error regarding not a valid month and when I try change it around i'm getting invalid number error.
ORA-01843: not a valid month ORA-06512: at "SYS.DBMS_SQL"
Code:
CREATE TABLE ExpenseReport (
ERNo NUMERIC(10) NOT NULL,
ERDesc VARCHAR(255) NOT NULL,
ERSubmitDate DATE DEFAULT CURRENT_TIMESTAMP,
ERStatusDate DATE NOT NULL,
ERStatus VARCHAR(8) DEFAULT 'PENDING',
SubmitUserNo NUMERIC(10) NOT NULL,
ApprUserNo NUMERIC(10) NOT NULL,
CONSTRAINT ExpenseReport_CK1 CHECK (ERStatusDate >= ERSubmitDate),
CONSTRAINT ExpenseReport_CK2 CHECK (ERStatus = 'PENDING'/'APPROVED'/'DENIED'),
CONSTRAINT ExpenseReport_PK1 PRIMARY KEY(ERNo),
CONSTRAINT ExpenseReport_FK1 FOREIGN KEY(SubmitUserNo) REFERENCES Users(UserNo),
CONSTRAINT ExpenseReport_FK2 FOREIGN KEY(ApprUserNo) REFERENCES (USerNo)
);
INSERT INTO ExpenseReport
(ERNo, ERDesc, ERSubmitDate, ERStatusDate, ERStatus, SubmitUserNo, ApprUSerNo)
VALUES (1,'Sales Presentation','8/10/2002','8/26/2002','APPROVED',3,4);
I've also tried using the TO_DATE but having no luck there,
by any chance can anyone see where i'm going wrong.
Use the DATE keyword and standard date formats:
INSERT INTO ExpenseReport (ERNo, ERDesc, ERSubmitDate, ERStatusDate, ERStatus, SubmitUserNo, ApprUSerNo)
VALUES (1, 'Sales Presentation', DATE '2001-08-10', DATE '2001-08-2006', 'APPROVED', 3, 4);
In addition to the satisfaction of using standard date formats, this protects you against changes in local settings.
In your DDL statement:
CONSTRAINT ExpenseReport_CK2 CHECK (ERStatus = 'PENDING'/'APPROVED'/'DENIED')
Should be:
CONSTRAINT ExpenseReport_CK2 CHECK (ERStatus IN ( 'PENDING', 'APPROVED', 'DENIED' ) )
When you are trying to insert values the check constraint is being evaluated and it is trying to perform a division operation on the three string values'PENDING'/'APPROVED'/'DENIED' which results in ORA-01722: invalid number.
Once you change this then using TO_DATE('01/01/02','DD/MM/YY') (as you wrote in comments) or an ANSI date literal DATE '2002-01-01' should work in your DML statements.
(Note: Be careful using 2-digit years or you can find that dates are inserted with the wrong century.)
Check your date format: select sysdate from dual;
and enter as it show. OR
change your date format: alter session set nls_date_format= 'DD-Mon-YYYY HH24:MI:SS';
It Was Easy :
if Your code Like This just remove hem and write that
Example :
Your code : values ('30178','K111', '22/12/2008')
Do This : values ('30178','K111', '22/Dec/2008')
Microsoft SQL Server 2016 (RTM) - 13.0.1601.5 (X64)
Copyright (c) Microsoft Corporation Express Edition (64-bit) on Windows 10 Pro 6.3 (Build 14393)
Server Collation: SQL_Latin1_General_CP1_CI_AS
Language: English (United States)
I'm using internal getdate() function to automatically fill a DateCreated column of DATE datatype.
As a matter of fact when a new product is entered I can see date values are being created in table in MM/dd/YYYY format (i.e. 3/18/2017).
Why is that? Is there a way to force getdate() to use the ISO 8061 format?
CREATE TABLE [dbo].[Products]
(
[ID] INT IDENTITY (1, 1) NOT NULL,
[Name] NVARCHAR (50) NOT NULL,
[Description] NVARCHAR (500) NOT NULL,
[IsDeleted] BIT NOT NULL,
[IsApproved] BIT NOT NULL,
[CategoryID] INT NOT NULL,
[UserID] NVARCHAR (MAX) NOT NULL,
[DateCreated] DATE DEFAULT (getdate()) NULL,
[DateExpire] DATE CONSTRAINT [CONSTRAINT_NAME] DEFAULT (dateadd(month,(1),getdate())) NULL,
[DateLastModified] DATE DEFAULT (getdate()) NULL,
CONSTRAINT [PK_dbo.Products]
PRIMARY KEY CLUSTERED ([ID] ASC),
CONSTRAINT [FK_dbo.Products_dbo.Categories_CategoryID]
FOREIGN KEY ([CategoryID]) REFERENCES [dbo].[Categories] ([ID])
);
The value of date and datetime data type is not stored with format in sql server. If you want to see the date in a different format you can manipulate the way that date and datetime data types are displayed when converted to a varchar (or nvarchar,nchar,char) data type using some built in functions.
Most often with convert() styles
select convert(varchar(10),getdate(),120)
returns: 2017-03-19
In sql server 2012+ you can use format()
select format(getdate(),'yyyy-MM-dd')
returns: 2017-03-19
But format() can be slower, take a look here: format() is nice and all, but… - Aaron Bertand
The format is not set in the data as stored for the date data types.
You can however set the format to be used for the visual display of dates.
SET DATEFORMAT { format | #format_var }
-- For example set date format to day/month/year.
SET DATEFORMAT dmy;
GO
format | #format_var
Is the order of the date parts. Valid parameters are mdy, dmy, ymd, ydm, myd, and dym.
Note ydm is not supported for date, datetime2 and datetimeoffset data types.
Just to add clarity this differs from the date and time styles format as as varchar for instance in:
CONVERT(VARCHAR(20), GETDATE(), 100)
I am trying to use SQL commands to add a field called Birthday to a Customers Table. My command is
ALTER TABLE Customers ADD COLUMN Birthday
I keep getting a syntax error in the field definition. What am I doing wrong?
The query need datatype for birthday, Ex:
ALTER TABLE Customers ADD COLUMN Birthday datetime
You need to specity type for your column. Assuming Birthday of type DATETIME and NOT NULL, The syntax for adding column is:
ALTER TABLE Customers
ADD Birthday DATETIME NOT NULL
Additional column Birthday must have it's datatype, such as DATE, DATETIME etc.
ALTER TABLE Customers
ADD COLUMN Birthday DATETIME
You need to specify a type for the Birthday field. The syntax may depend on what the type is and which version of SQL you are using (you haven't specified either). Assuming you're using Microsoft SQL, and given that it's a birthday (and you don't need a time), and there are likely customers for whom you won't have a birthday, I'd recommend:
ALTER TABLE Customers
ADD COLUMN Birthday DATE CONSTRAINT Customers_Birthday_Default DEFAULT NULL
alter TABLE Customers
ADD Birthday DATETIME
GO
update Customers set Birthday = GETDATE()
GO
alter TABLE Customers
alter column Birthday DATETIME NOT NULL
GO
alter table Customers add constraint df_Customers_note default (getDATE()) for Birthday
GO