I am using SQL Server 2012 and I have the following User Defined Table Type
CREATE TYPE [dbo].[IdentifierCodeTable] AS TABLE(
[Id] [dbo].[Identifier] NULL,
[Code] [dbo].[Code] NULL
)
I am trying to enforce that Id must be Unique except for NULL values.
I have the following code and it is working fine for NON NULL values but when I try to insert 2 NULL values it does not allow me to do it.
CREATE TYPE [dbo].[IdentifierCodeTable] AS TABLE(
[Id] [dbo].[Identifier] NULL,
[Code] [dbo].[Code] NULL,
UNIQUE(Id)
)
Is there any way to exclude the NULL values from that UNIQUE Constraint like I can do in the regular indexes with the filter?
I think this is all I need to know (It is SQL Server 2008 but i think it applies to SQL Server 2012 either).
A nonclustered index cannot be created on a user-defined table type unless the index is the result of creating a PRIMARY KEY or UNIQUE constraint on the user-defined table type. (SQL Server enforces any UNIQUE or PRIMARY KEY constraint by using an index.)
Source: https://technet.microsoft.com/en-us/library/bb522526%28v=sql.105%29.aspx
Related
I need to create an Index on two columns (within a table variable) which do not form unique key.
Table structure is shown below -
DECLARE #Sample TABLE (
[AssetSk] [int] NOT NULL,
[DateSk] [int] NOT NULL,
[Count] [numeric](38, 2) NULL
)
I am trying to add Index as shown below -
INDEX AD1 CLUSTERED([AssetSk],[DateSk])
However it gives me the following error while running it on SQL Server 2012
" Incorrect syntax near 'INDEX'. If this is intended as a part of a table hint, A WITH keyword and parenthesis are now required. See SQL Server Books Online for proper syntax."
However, this runs perfectly on SQL Server 2014 . Is there any way that I could run it on SQL Server 2012 .
You can't build index other than unique key at table variable using SQL Server version prior to 2014.
However, you can do the trick: add one more colummn with autoincremented value and create unique index including columns you need and this new one.
DECLARE #Sample TABLE (
[ID] bigint identity(1, 1),
[AssetSk] [int] NOT NULL,
[DateSk] [int] NOT NULL,
[Count] [numeric](38, 2) NULL,
UNIQUE NONCLUSTERED ([AssetSk],[DateSk], ID)
)
Update: In fact, creation of such an index on table variable can be useless. Normally SQL Server estimates that a table variable has a single row, thus it will not use this index with relatively high probability.
As far as I know in SQL Server 2012 and below you can not add indexes to table variables. To add an index you must declare the table like this:
CREATE TABLE #Sample (
[AssetSk] [int] NOT NULL,
[DateSk] [int] NOT NULL,
[Count] [numeric](38, 2) NULL
)
And after you can create the index you need like this
CREATE CLUSTERED INDEX IX_MyIndex
ON #Sample ([AssetSk],[DateSk])
Of course, after you're done with the table in four function you can call
DROP TABLE #Sample
For a specific task I need to store the identity of a row in a tabel to access it later. Most of these tables do NOT have a numeric ID and the primary key sometimes consists of multiple fields. VARCHAR & INT combined.
Background info:
The participating tables have a trigger storing delete, update and insert events in a general 'sync' tabel (Oracle v11). Every 15 minutes a script is then launched to update corresponding tables in a remote database (SQL Server 2012).
One solution I came up with was to use multiple columns in this 'sync' table, 3 INT columns and 3 VARCHAR columns. A table with 2 VARCHAR columns would then use 2 VARCHAR columns in this 'sync' table.
A better/nicer solution would be to 'select' the value of the primary key and store this in this table.
Example:
CREATE TABLE [dbo].[Workers](
[company] [nvarchar](50) NOT NULL,
[number] [int] NOT NULL,
[name] [nvarchar](50) NOT NULL,
CONSTRAINT [PK_Workers] PRIMARY KEY CLUSTERED ( [company] ASC, [number] ASC )
)
// Fails:
SELECT [PK_Workers], [name] FROM [dbo].[Workers]
UPDATE [dbo].[Workers] SET [name]='new name' WHERE [PK_Workers]=#PKWorkers
// Bad (?) but works:
SELECT ([company] + CAST([number] AS NVARCHAR)) PK, [name] FROM [dbo].[Workers];
UPDATE [dbo].[Workers] SET [name]='newname' WHERE ([company] + CAST([number] AS NVARCHAR))=#PK
The [PK_Workers] fails in these queries. Is there another way to get this value without manually combining and casting the index?
Or is there some other way to do this that I don't know?
for each table create a function returning a concatenated primary key. create a function based index on this function too. then use this function in SELECT and WHERE clauses
I am trying to create table having different indexes with single query but H2 gives Error for example:
create table tbl_Cust
(
id int primary key auto_increment not null,
fid int,
c_name varchar(50),
INDEX (fid)
);
but this gives error as
Unknown data type: "("; SQL statement:
[Error Code: 50004]
[SQL State: HY004]
Due to this I have to run 2 different queries to create table with Index. First query to create table and then second query to add index with
create INDEX c_fid on tbl_Cust(fid);
Is there something wrong in my query or H2 simply does not support this creation of table with index in single query?
Interesting question. The solution is even more interesting, as it involves MySQL compatibility mode.
It's actually possible to perform the exact same command you wrote without any modification, provided you just add to your jdbc url the MySQL mode.
Example URL like this: jdbc:h2:mem:;mode=mysql
SQL remains:
create table tbl_Cust
(
id int primary key auto_increment not null,
fid int,
c_name varchar(50),
INDEX (fid)
);
Update count: 0
(15 ms)
Too bad I did not see this question earlier... Hopefully the solution might become handy one day to someone :-)
I could resolve the problem. According to
http://www.h2database.com/html/grammar.html#create_index
I modified the query. It works fine with my H2 server.
CREATE TABLE subscription_validator (
application_id int(11) NOT NULL,
api_id int(11) NOT NULL,
validator_id int(11) NOT NULL,
PRIMARY KEY (application_id,api_id),
CONSTRAINT subscription_validator_ibfk_1 FOREIGN KEY (validator_id) REFERENCES validator (id) ON UPDATE CASCADE
);
CREATE INDEX validator_id ON subscription_validator(validator_id);
I want to create a named default value in an ANSI compliant fashion, if possible, in a CREATE TABLE statement
If I try to add the CONSTRAINT as I would normally write it in an ALTER TABLE statement, it fails (at least in SQL SERVER, though I emphasise I am hoping to find an ANSI complaint statement as I would prefer it to work over a variety of Ado.NET DbConnections).
Example:
CREATE TABLE [dbo].[MyExample]
(
Id int NOT NULL IDENTITY (1, 1),
Name varchar(512) NOT NULL,
IsActive bit NOT NULL,
CONSTRAINT PK_MyExample PRIMARY KEY CLUSTERED (Id),
CONSTRAINT DF_MyExample_IsActive DEFAULT (1) FOR [IsActive]
)
Error:
Incorrect syntax near 'for'.
In terms of the SQL-92 Standard -- which is both ISO (I = International) and ANSI (A + American), by the way -- DEFAULT is not a constraint that may be given a name. In SQL-92 the DEFAULT can only be defined inline with the column definition and must be between the data type and the NOT NULL (if used) e.g.
CREATE TABLE T (c INTEGER DEFAULT 1 NOT NULL UNIQUE);
Note you have much non-Standard syntax in your small example:
square brackets as quoted identifiers (should be double quotes)
non-compliant data type (e.g. incorrect bit null behaviour)
abbreviated data types (e.g. int rather than INTEGER)
IDENTITY
CLUSTERED
Is it not ANSI compliant?
CREATE TABLE [dbo].[MyExample]
(
Id int NOT NULL IDENTITY (1, 1),
Name varchar(512) NOT NULL,
IsActive bit NOT NULL CONSTRAINT DF_MyExample_IsActive DEFAULT (1),
CONSTRAINT PK_MyExample PRIMARY KEY CLUSTERED (Id)
)
Is there a way in SQL Server to create a table with a primary key that auto-increments itself? I've been looking at the "UniqueIdentifier" type, but this doesn't seem to do what I expect.
Currently, I have something like this:
CREATE TABLE [dbo].[MyTable](
[Date] [datetime] NOT NULL,
[MyField1] [nchar](50) NOT NULL,
[MyField2] [nvarchar](max) NULL,
[Key] [uniqueidentifier] NOT NULL
) ON [PRIMARY]
Basically, I want KEY to start at 1 and just increment itself for each record.
You're looking for the IDENTITY property.
From the documentation:
Creates an identity column in a table.
This property is used with the CREATE
TABLE and ALTER TABLE Transact-SQL
statements.
IDENTITY [ (seed , increment) ]
seed
Is the value that is used for the very
first row loaded into the table.
increment
Is the incremental value that is added
to the identity value of the previous
row that was loaded.
You must specify both the seed and
increment or neither. If neither is
specified, the default is (1,1).
Btw, all of this is also easily achieved from Sql Server's mgmt UI. Just right click on your table and select design. Then select the proper column and set the IDENTITY property.
Define your primary key in the table create statement like this:
[Key] [int] IDENTITY(1,1) NOT NULL