I have a table which has a composite primary key consisting of four columns, one of them being a datetime called Day.
The nice thing afaik with this composite key is that it prevents duplicate entries in the table for any given day. But the problem is probably two-fold
1. multiple columns need to be used for joins and I think this might degrade performance? 2. in client applications such as asp.net these primary keys must be sent in the query string and the query string becomes long and a little bit unmanagable.
A possible solutions I'm thinking of is dropping the existing primary key and creating a new identity column and a composite unique index on the columns from the existing composite key.
I would like to have some tips, recommendations and alternatives for what I should do in this case.
DECLARE cLoop cursor for select TABLE_NAME from INFORMATION_SCHEMA.TABLES where TABLE_CATALOG=@vcDB and TABLE_SCHEMA=@vcSchema order by TABLE_NAME ASC
open cLoop
FETCH NEXT FROM cLoop INTO @vcTable WHILE @@FETCH_STATUS=0 BEGIN if not exists (SELECT * FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS WHERE TABLE_SCHEMA = @vcSchema AND TABLE_NAME = @vcTable AND CONSTRAINT_TYPE = 'PRIMARY KEY') print @vcTable + ' does not have a primary key'
FETCH NEXT FROM cLoop INTO @vcTable END Close cLoop DEALLOCATE cLoop
I have two tables (categories & listings) which create a many-to-many relationship.
I have created an interim table with the primary keys from each table as a composite primary key...(cat_id & list_id).
How does the interim table get populated with the id's?
When I do an insert statement to insert data into the categories table, the cat_id field is automatically generated...same with the listings table, but when (and how) does the primary key data get into the interim table.
Hi, i want to make a reference from a table on itself. The table has a composite Primary Key. But I just want to refernce the TEstCaseID. So whats wrong? Can anyone help me?
Im wondering if it is possible to write a procedure that check two identical tables for any missing records. The table design is excatly the same, but some records (of the 40,000) have not copied over to the second table.
I have a sql sever 2005 express table with an automatically incremented primary key field. I use a Detailsview to insert new records and on the Detailsview itemInserted event, i send out automated notification emails. I then received two automated emails(indicating two records have been inserted) but looking at the database, the records are not there. Whats confusing me is that even the tables primary key field had been incremented by two, an indication that indeed the two records should actually be in table. Recovering these records is not abig deal because i can re-enter them but iam wondering what the possible cause is. How come the id field was even incremented and the records are not there yet iam 100% sure no one deleted them. Its only me who can delete a record. And then how come i insert new records now and they are all there in the database but now with two id numbers for those missing records skipped. Its not crucial data but for my learning, i feel i deserve understanding why it happened because next time, it might be costly.
I have two tables of book information. One that has descriptions of thebook in it, and the isbn, and the other that has the book title,inventory data, prices, the isbn.Because of some techncal constraints I won't get into now, I can'tcombine them both into one table. No problem. Things are going fine aslong as there is a description in the one table to corrispond to theisbn and other data in the other table.However, about half of the products are not yet entered into thedescrition table. I'd like to run a sql query that pulls up all theisbns that don't exist in the other. In other words, I'd like to get aquery that tells me exactly which isbns do not yet have descrition datain them. I know there is some sql that says to search from one filewhere the number does not exist in the other, but it slips my mind. Cansomeone help me on this please?Thank you!Bill*** Sent via Developersdex http://www.developersdex.com ***Don't just participate in USENET...get rewarded for it!
I am trying to write triggers on each tables in my database to audit data changes. My AuditLog table consists of the following columns -
LoginName varchar(100) - user name Action varchar(5) - this will store 'INSERT','UPDATE','DELETE' TableName varchar(30) - name of the table updated PrimaryKey int - primary key of the record updated ColumnName varchar(30) - name of the column updated OldValue varchar(1000) - old value converted to varchar NewValue varchar(1000) - new value converted to varchar RecUpdDate datetime - record update date.
This table design will work for tables with single column primary keys. However, it will not work for tables with composite primary keys. Any suggestions on how to make this work with composite primary keys? I prefer not to change the tables in my database to use single column primary key.
I have a problem with the primary keys in my main Db , I want to setup replication and looks like someone tampered with my database by removing the primary keys.and in order to setup replication i need this table to have primary keys .THere are duplicates in that table but they are nessecary...and for this reason the primary keys do not want to "stick" when i try and specify them.Can anybody help
ALTER TABLE [Students] WITH CHECK ADD CONSTRAINT [FK_Students_Schools] FOREIGN KEY([SchoolId]) REFERENCES [Schools] ([SchoolId])
What kind of index would ensure best performance for INSERTs/UPDATEs, so that SQL Server can most efficiently check the FK constraints? Would it be simply:
CREATE INDEX IX_Students_SchlId ON Students (SchoolId) Or CREATE INDEX IX_Students_SchlId ON Students (SchoolId, StudentId)
In other words, what's best practice for adding an index which best supports a Foreign Key constraint?
We are facing the following issue, several machines/users that are executing very often a command similar to :
INSERT INTO TableName (FieldOne,FieldTwo) VALUES ('ValueOne','ValueTwo'); SELECT SCOPE_IDENTITY() AS Table_ID;
Where TableName has a primary key defined as identity(1,1).and that Table_ID is being used as reference in others tables
These queries are executed using different dababase users and among several diffrent apps..The Problem is that we are detecting lost block of "Table_ID's" as the other tables shows the InsertedID as a reference, but the TableName table lacks of this ID record. In other words, the INSERT seems to work, the SCOPE_Identity returns an InsertedID, and the other tables are populated using this number. However, when we query the TableName table the mentioned record does not exist. We are profiling the server and we're sure that there are no DELETE statement on the TableName table. This seems to be happening when the are either deadlocks or blocked processes. Whenever the deadlocks and locks disappear/solved, everything works as expected.why the Scope_Identity returns the Inserted ID if the INSERT action had failed.
What query do I use to list the primary key for each user table, i.e.TABLE | PRIMARY_KEY |Regards,Alan*** Sent via Developersdex http://www.developersdex.com ***Don't just participate in USENET...get rewarded for it!
SELECT T.TABLE_NAME,C.COLUMN_NAME FROM INFORMATION_SCHEMA.TABLES T JOIN INFORMATION_SCHEMA.COLUMNS C ON T.TABLE_NAME = C.TABLE_NAME WHERE OBJECTPROPERTY(OBJECT_ID(T.TABLE_NAME), 'TableHasIdentity') = 0 AND T.TABLE_TYPE = 'BASE TABLE' AND OBJECTPROPERTY(OBJECT_ID(C.COLUMN_NAME),'IsPrimary Key') = 1 ORDER BY T.TABLE_NAME,C.COLUMN_NAME
This is giving me bogus results...
SELECT * FROM INFORMATION_SCHEMA.COLUMNS WHERE OBJECTPROPERTY(OBJECT_ID(COLUMN_NAME),'IsPrimaryKe y') = 1
I have PK's all over the place. What gives? Too many cocktails with lunch?
I wrote a query that when run, will give me a listing of all tables in a database, and whether or not those table have primary keys.
Here's the query:
Code Snippet select so.name, si.name from sysobjects so left outer JOIN sysindexes si on so.id = si.id where si.status = '2066' and so.type = 'u' order by so.name asc
It works for the most part save for one small (big) problem. It gives me a list of tables that have a corresponding primary key, but doesn't list those without one. For example, in one database I run this query. I know for a fact that there are 26 tables in this database, and my query returns 16 rows (one for each table with a PK). I'd like to see those as well as those without one, with a NULL in the NAME column for the PK.
I've tried every join combo under the sun and still can't get the desired results.
I wanted to find all occurrences of ADRSCODE in a Database where ADRSCODE is in either an Index or a Primary Key.
I know how to get all of the occurences of ADRSCODE in a database and the table associated with it, I just want to tack on the Index and/or primary key.
I have recently been looking at a database and wondered if anyone can tell me what the advantages are supporting a unique collumn, which can essentially be seen as the primary key, with an identity seed integer primary key.
For example:
id [unique integer auto incremented primary key - not null], ClientCode [unique index varchar - not null], name [varchar null], surname [varchar null]
isn't it just better to use ClientCode as the primary key straight of because when one references the above table, it can be done easier with the ClientCode since you dont have to do a lookup on the ClientCode everytime.
Does anyone have a script that will roll through the tables in a database and identify tables without primary keys defined? I did not see any in the online script database.
Hello,We imported a bunch of tables from a database and realized that theprimary keys weren't copied to the destination db. In order to re-create the keys, we need to know which tables have them. Is there acommand that I can use (on the source db) to find out which tablescontain primary keys? The db has hundreds of tables and I'd rather notgo through each one to see which has a primary key.Also, for future reference, is there a way to include the primary keyon an import?Thanks,Peps
I've created a table called Employees with a primary key called EmployeeID. Â The table contains EmployeeID, FirstName and LastName columns. Â I now want to create a table called Team which will contain the columns TeamID, EmployeeID (to reference the column EmployeeID from the Employee table) and a column called TeamName. Â Sql won't let me create multiple primary keys in one table (I did think that was the case ) key but yet if I look at the Adventure Works database in the Person.PersonPhone table, I can see three primary keys defined.
I have run into a problem, i need to find out that column(s) in a table that makes the primary key. I thought that this code did the trick. *** DECLARE @c varchar(4000), @t varchar(128) SET @c = '' SET @t='contact_pmc_contact_relations' Select @c = @c + c.name + ',' FROM syscolumns c INNER JOIN sysobjects o ON o.id = c.id inner join sysindexkeys k on o.id = k.id WHERE o.name = @t and k.colid = c.colid ORDER BY c.colid SELECT Substring(@c, 1, Datalength(@c) - 1) ***
This works in most of my cases. But i have encounterd tabels where this code doesn't work. Here is a dump from one of the tabels where it doesn't work. SELECT * FROM sysindexkeys WHERE (id = 933578364) <--id of the table *** id indid colid keyno 933578364 1 1 1 933578364 1 2 2 933578364 2 1 1 933578364 3 2 1 933578364 4 3 1 933578364 5 4 1 933578364 6 5 1 933578364 7 6 1 933578364 8 7 1
Not sure if that dump made any sense, but i hope it did. If i look at the table in SQL Enterprise manager there is no relations, no indexes only my primarykey made up with 2 columns (column id 1 and 2).
Has any1 noticed that when they are transferring SQL tables from one server (or machine) to another that the primary keys drop from the table (or is it just me). If so, has someone figured out why? and how to rectify this (apparent) error.
I have 2 tables say table1 and table2 with the same structure. Each recordis identified by a field 'SerialNo'. Now there should be a total of 500000records in both tables with serialno from 1 to 500000. Either a record is intable1 or table2. I want to find records (or SerialNo's) that are inneither table (if deleted by accident etc). What would be the sql query?I'm using SQL 6.5thx
How can i enter Default Values of " " to all the columns of type characterof all the tables (excluding system tables) and Default Values of 0of all columns of type numbers. Excluding all primary key columns.Thank you
We are trying to find out the difference between tables in CUSTOMER database and CUSTOMER_coded database. The goal is to find out if there are any columns missing in each table of CUSTOMER_coded database.
We need the list of tables in CUSTOMER_coded database that misses some column compare to its peer in CUSTOMER database (list of columns being missing also).
I googled, but I get only all the columns in tables of database.
I need missing columns of all the tables when we compare these 2 databases( CUSTOMER and CUSTOMER_coded databases).
Uma writes "Hi Dear, I have A Table , Which Primary key consists of 6 columns. total Number of Columns in the table are 16. Now i Want to Convert my Composite Primary key into simple primary key.there are already 2200 records in the table and no referential integrity (foriegn key ) exist.
may i convert Composite Primary key into simple primary key in thr table like this.
I have been reading a bit about db design practices for SQL server and have learned how bad composite keys are!
However, I just wanted to know what the accepted alternatives are (and why they should be used);
Previously I was under the impression that adding autonumber style keys to tables are bad (extra col, doesn€™t allow unique checking of tuples). I want a table which is made up of two (single) primary keys from other tables, but the entries in the new table to be unique (and efficient). (note this is going to be part of a db which is going to grow to become very large).
Could somebody please explain to me how to create a foreign key from a table that has two composite keys? I have a table, UserPrecedence, with two composite keys - up_owner, owner_userID. I have a second table, Users, that has the primary key "emailAddress" and a userID table to which all other tables point their FK columns.
I want the userID column in Users to be the FK of the owner_userID column in UserPrecedence but the Modify Table view complains that "both sides of the relationship must have the same number of columns" when I try to create the relationship.
I am guessing this is because its a composite primary key. Can somebody explain to me how this is done correctly (and why)?
I use the following 3 sets of sql code in SQL Server Management Studio Express (SSMSE) to import the csv data/files to 3 dbo.Tables via CREATE TABLE & BUKL INSERT operations:
-- ImportCSVprojects.sql --
USE ChemDatabase
GO
CREATE TABLE Projects
(
ProjectID int,
ProjectName nvarchar(25),
LabName nvarchar(25)
);
BULK INSERT dbo.Projects
FROM 'c:myfileProjects.csv'
WITH
(
FIELDTERMINATOR = ',',
ROWTERMINATOR = ''
)
GO ======================================= -- ImportCSVsamples.sql --
USE ChemDatabase
GO
CREATE TABLE Samples
(
SampleID int,
SampleName nvarchar(25),
Matrix nvarchar(25),
SampleType nvarchar(25),
ChemGroup nvarchar(25),
ProjectID int
);
BULK INSERT dbo.Samples
FROM 'c:myfileSamples.csv'
WITH
(
FIELDTERMINATOR = ',',
ROWTERMINATOR = ''
)
GO ========================================= -- ImportCSVtestResult.sql --
USE ChemDatabase
GO
CREATE TABLE TestResults
(
AnalyteID int,
AnalyteName nvarchar(25),
Result decimal(9,3),
UnitForConc nvarchar(25),
SampleID int
);
BULK INSERT dbo.TestResults
FROM 'c:myfileLabTests.csv'
WITH
(
FIELDTERMINATOR = ',',
ROWTERMINATOR = ''
)
GO
======================================== The 3 csv files were successfully imported into the ChemDatabase of my SSMSE.
2 questions to ask: (1) How can I designate the Primary and Foreign Keys to these 3 dbo Tables? Should I do this "designate" thing after the 3 dbo Tables are done or during the "Importing" period? (2) How can I set up the relationships among these 3 dbo Tables?
I'm going through my tables and rewriting them so that I can create relationship-based constraints and create foreign keys among my tables. I didn't have a problem with a few of the tables but I seem to have come across a slightly confusing hiccup.
Here's the query for my Classes table:
Code:
CREATE TABLE Classes ( class_id INT IDENTITY PRIMARY KEY NOT NULL,
This statement runs without problems and I Create the relationship with my Users table just fine, having renamed it to teacher_id. I have a 1:n relationship between users and tables AND an n:m relationship because a user can be a student or a teacher, the difference is one field, user_type, which denotes what type of user a person is. In any case, the relationship that's 1:n from users to classes is that of the teacher instructing the class. The problem exists when I run my query for the intermediary table between the class and the gradebook:
Code:
CREATE TABLE Classes_have_Grades ( class_id INT PRIMARY KEY NOT NULL,
Query Analyzer spits out: Quote: Originally Posted by Query Analyzer There are no primary or candidate keys in the referenced table 'Classes' that match the referencing column list in the foreign key 'Classes_have_gradesFKIndex2'. Now, I know in SQL Server 2000 you can only have one primary key. Does that mean I can have a multi-columned Primary key (which is in fact what I would like) or does that mean that just one field can be a primary key and that a table can have only the one primary key?
In addition, what is a "candidate" key? Will making the other fields "Candidate" keys solve my problem?
