I am using VS 2008 and SQL Server 2005. And the problem is that when I insert a new record which is string data. It continues on entering the same data which is already exiting in the table, again and again. But I want that where my insert query is running. I place the check there that it does not allow similar data in the table.
My scenario:
I have to decide on these two string columns: 'source' and 'destination'
If similar source and destination occur in any record we must stop we the entry on record.
Share the solution.
The easiest way to do it is by putting a 'UNIQUE constraint' on your database. Then, each time an SQL UPDATE or an SQL INSERT is executed, the database server would check the validity of the new SQL action and cancel it if it violates your data integrity constraing.
For example (copying from this SQL tutorial):
CREATE TABLE Persons
(
P_Id int NOT NULL UNIQUE,
LastName varchar(255) NOT NULL,
FirstName varchar(255),
Address varchar(255),
City varchar(255)
)
If you want to add a UNIQUE constraint on two columns, you could use such a statement:
CREATE TABLE Example
(Col1 int NOT NULL,
Col2 int NOT NULL,
UNIQUE (Col1, Col2)
)
Hope I helped!
Related
I'm working on a database for my school project in which I have to produce a functional database by normalizing sample tables given to us.
One table I'm having trouble with is itineraries. I produce 3 tables from the normalization which are "Destinations", "Itineraries" and "Itinerary_Destinations".
The code for Destinations is:
create table Destinations
(
DestinationID varchar(5) primary key,
Name varchar(45)
);
The code for Itineraries is:
create table Itineraries
(
ItineraryID varchar(5),
Name varchar(45)
);
The code for the last table is:
create table Itinerary_Destinations
(
DI varchar(5) primary key,
ItineraryID varchar(5) foreign key references Itineraries(ItineraryID),
Itinerary_Name varchar(45),
DestinationID varchar(5) foreign key references Destinations(DestinationID),
Destination_Name varchar(45)
);
Data has already been inserted into all 3 tables with the exception of 'Destination_Name' and 'Itinerary_Name' columns. The code I'm attempting to use is returning as error. The code is shown below.
insert into Itinerary_Destinations (Itinerary_name)
select Name from Itineraries where
Itineraries.ItineraryID = ItineraryID;
The error it returns is
Msg 515, Level 16, State 2, Line 1 Cannot insert the value NULL into
column 'DI', table 'DDDAssignment.dbo.Itinerary_Destinations'; column
does not allow nulls. INSERT fails. The statement has been terminated.
Is there a method to accomplish the task of inserting the Destination_Name and Itinerary_Name without creating new records that require primary keys?
Or should I do it manually?
If you want to modify records which already exist, then you should be using an UPDATE rather than an INSERT:
UPDATE a
SET Itinerary_name = b.Name
FROM Itinerary_Destinations a
INNER JOIN Itinerary_name b
ON a.ItineraryID = b.ItineraryID;
But, if you do have some data which is not already logically associated with the Itinerary_Destinations table, then using an insert is appropriate.
use coalesce funtion in case null it will insert blank string, as your column does not allow null value thats why you got that error in your query
insert into Itinerary_Destinations (Itinerary_name)
select coalesce(Name,' ') from Itineraries where
Itineraries.ItineraryID = ItineraryID;
Hello and sorry for newbie question.
I have a very simple SSIS project that imports customer names from file. It all works now fine, however there are multiple entries of same name and I dont want duplicates.
This works just fine, however it populates duplicates:
CREATE TABLE [SLSales].[dbo].[Customer] (
id BIGINT IDENTITY NOT NULL PRIMARY KEY,
name NVARCHAR(100) NOT NULL
);
However, when I try to use this:
CREATE TABLE [SLSales].[dbo].[Customer] (
id BIGINT IDENTITY NOT NULL PRIMARY KEY,
name NVARCHAR(100) NOT NULL UNIQUE
);
All records fail and I get a mysterious -1071607685 error code.
The SSIS way is to:
Load the data from Source
GROUP BY [name] in your case because you can have same name in file
Run through a Lookup (Match and NoMatch outputs)
Insert No Match
Update matches (or in your case you might want to just ignore)
I am new to SQL and I am trying to run a CREATE TABLE query in Ms Access 2016 but I get an error saying that "mytablename" already exits which can't be true because I also ran a DROP TABLE "mytablename" query and I got an error saying "mytablename" does not exist. Please help. Point me in the right direction at least. Here is the CREATE TABLE query.
CREATE TABLE Team(
Team_ID AUTOINCREMENT UNIQUE NOT NULL,
Name VARCHAR(40) NOT NULL,
Origin VARCHAR(40) NOT NULL,
NetWorth CURRENCY NOT NULL,
PRIMARY KEY(Team_ID)
);
See check by VBA and check by SQL for check existence of your database.
If table exists you can recreate (drop and create again) table. Alternative way is to create table if table is not exist and do nothing if table exists.
I have a table viz. expenses with three columns as under
ExpenseId int NOT NULL,
ExpenseName varchar(50) NOT NULL,
Invalid bit NOT NULL
To add a new column (OldCode char(4) not null), I used design feature for tables in Microsoft SQL Server Management Studio. But I get following error
'Expenses' table
- Unable to modify table. Cannot insert the value NULL into column 'OldCode', table 'TransportSystemMaster.dbo.Tmp_Expenses'; column does not allow nulls. INSERT fails. The statement has been terminated.
Incidentally I have been able to add same column with same specifications to other tables of the same database.
Any help?
Your Table Consist of Existing Records
and you are pushing a new column of type NOT NULL.
so for older records the data have to be something.
try something like this
ALTER TABLE MY_TABLE ADD Column_name INT NULL
GO
UPDATE MY_TABLE <set valid not null values for your column>
GO
ALTER TABLE MY_TABLE ALTER COLUMN Column_name INT NOT NULL
GO
Since OldCode is NOT NULL, you should specify a default value for it.
when you have some rows on your table you can't add a column that is not nullable you should provide a default value for it
Alter Table table_name add OldCode int not null DEFAULT(0);
You have to specify values for all the 4 fields of the table, its purely because, while designing the table you set the definition of the columns to be not null. Again you are adding a new column called OldCode and setting to be not null, all ready existing records hasn't got a value. So that is the reason its complains
I am trying to create a fairly simple SQL Server trigger, hope someone can help.
I have a table with structure like this:
Table #1:
CREATE TABLE `teg_priority` (
`UCIDN` BIGINT(50) NULL DEFAULT NULL,
`CIDN` BIGINT(50) NOT NULL,
`CustomerName` VARCHAR(200) NOT NULL,
`NGM` VARCHAR(150) NULL DEFAULT NULL,
`Service_Manager` VARCHAR(150) NULL DEFAULT NULL,
`CBS` LONGTEXT NULL,
`Tag` VARCHAR(50) NOT NULL,
PRIMARY KEY (`CIDN`)
)
and another table (table #2):
CREATE TABLE `custalign` (
`UCIDN` BIGINT(20) NOT NULL,
`CIDN` BIGINT(20) NOT NULL,
`CustomerName` VARCHAR(255) NOT NULL,
PRIMARY KEY (`CIDN`)
)
I am trying to set up a trigger where every time a new record is inserted into the first table that the following query will be run as a trigger to update field UCIDN in table 1
update teg_priority
set teg_priority.UCIDN = (select UCIDN from custalign
where teg_priority.CIDN = custalign.CIDN)
The above query works i just don't know how to write it as a trigger statement.
Please help.
CREATE TRIGGER dbo.Teg_priority_after_insert
ON dbo.teg_priority AFTER INSERT
AS
UPDATE inserted
set inserted.UCIDN = (select UCIDN from custalign
where inserted.CIDN = custalign.CIDN)
That's your answer. You might consider a change in approach; assuming it doesn't require a total re-work of your process-flow. I can't really suggest more without knowing what you're ultimately trying to accomplish.
In SQL Server triggers, there is an inserted and a deleted table automatically-generated to which you may refer. Each respectively contains the new and old records as a result of whatever statement AFTER [INSERT],[UPDATE],[DELETE]. The inserted table is accessible to AFTER INSERT and UPDATE triggers, while the deleted table is accessible to AFTER UPDATE and DELETE triggers.
That might be more than you wanted to know, but I thought you'd benefit from a brief explanation of where the inserted table came from in my code.
[Insert all the usual caveats about trying not to use triggers wherever possible here.]
try out this..hope this will helps you
For MySQL
CREATE TRIGGER teg_priorityTrigger AFTER INSERT ON teg_priority
FOR EACH ROW
BEGIN
UPDATE inserted
set inserted.UCIDN = (select UCIDN from custalign
where inserted.CIDN = custalign.CIDN)
END
For SQL Server
CREATE TRIGGER teg_priorityTrigger ON dbo.teg_priority AFTER INSERT
AS
UPDATE inserted
set inserted.UCIDN = (select UCIDN from custalign
where inserted.CIDN = custalign.CIDN)
hope this will helps you...