I have a table which is to be replicated using Transactional Replication.
This table has a composite primary key . These are a combination of varchar and numeric columns.
I want to understand if this table can be replicated with a composite primary key?
Please let me know.
Thanks in advance.
Yes, this table can be replicated with a composite primary key. Just keep in mind with Transactional Replication there must be a declared primary key for the published table.
Considerations for Transactional Replication
Related
Does redis provide users to create data integrity or constraint? Like giving primary keys and foreign keys in sql. I can't seem to find it in the user manual. Thanks!
I recently created a relational database model and it has a lot of primary key and foreign key relations. I want to use clickhouse for my database but it turns out that clickhouse does not support foreign key and unique primary keys. Can someone tell me if I am missing anything here.
You are right. CH does not have unique & foreign constraints.
Moreover JOINs are not the best part of ClickHouse.
ClickHouse suggests to create single wide denormalized table and avoid joins as possible.
I am analysing the database tables and design, I have noticed that there is a table with a column interviewID which is a primary key to the table, it is also a foreign key, the relation says it is a foreign key to itself, how is this even possible. primary key says each value should be unique and not null but foreign key says it has to be one of the existing values? Something wrong with the design? or is there some logic behind this?
When you create a new foreign key in SQL Server Management Studio all controls are set to crazy defaults: a self-referential foreign key on the first column of the table (usually the primary key column). I think somebody did this and just hit save.
It has no purpose whatsoever. Delete it.
I needed to set change tracking in sql server 2008 table to true but it gave an error that the table has to have a primary key
Is there a way to enable change tracking without setting a primary key in my table
Is it a good programming practice not to set primary keys? I am creating a system but i don't want to set them on SQL tables
The Table must have primary key in order to enable Change tracking
Having primary keys on a table infarct is a good programming practice.
You can enable Change Tracking on a table which has Primary key.
It is must. Because Change Tracking works based on Primary key in a table.
You can find some more additional information from my Article
http://www.codeproject.com/Articles/537649/SQL-Server-Change-Tracking-CT#_comments
In a LDM I recently made, I have an entity which has the following structure:
Building_ID (Primary Key, Foreign Key),
Plant_ID (Foreign Key),
Build_Year (Primary Key),
Size
I need to create a table in a SQL database using this design. The question I'm running into is how do I handle the primary keys here? Is it OK for a SQL table to have multiple primary keys? If the answer to this question is yes, then which column should act as the unique index? Should I create a new column to act as the unique index identifier?
Any SQL table for any relational database system (SQL Server, Oracle, Firebird, IBM DB2, Sybase etc.) I know can only ever have one primary key - after all, it's the primary key - there can only ever be one.
However, a primary key can be made up from multiple columns (called a "compound primary key"). There are downsides such as: all foreign key constraints from other tables also must specify all columns in the compound PK, thus making joining the tables a bit of a pain (since you need to specify all equality constraints for all columns included in the key in your JOIN).
Besides a primary key, you can also have multiple alternate keys - other column(s) that could also identify the row uniquely. Those make excellent candidates for e.g. indices, if those can help you speed up access to the table (but don't over-index your tables! Less is more)