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Can primary key varchar?
It is perfectly acceptable to use a varchar column as the primary key.
Is clustered index automatically created on primary key?
When you create a PRIMARY KEY constraint, a unique clustered index on the column or columns is automatically created if a clustered index on the table does not already exist and you do not specify a unique nonclustered index. The primary key column cannot allow NULL values.
Can we delete clustered index?
To drop a clustered or nonclustered index, issue a DROP INDEX command. When you do this, the metadata, statistics, and index pages are removed. If you drop a clustered index, the table will become a heap. Once an index has been dropped, it can’t be rebuilt – it must be created again.
How to change primary key from nonclustered to clustered?
Change a Primary Key from Nonclustered to Clustered 1 Drop the existing clustered index first (IX_TableX_FieldB): DROP INDEX TableX.IX_TableX_FieldB 2 Create a (temporary) UNIQUE constraint on the unique fields referenced in the primary key ALTER TABLE TableX ADD… 3 Drop the PRIMARY KEY ALTER TABLE TableX DROP CONSTRAINT PK_TableX More
Which is the best primary key in nvarchar?
Regardless, your best option, by far, is to use [ID_CODE] as the Clustered PK, use that field in related tables as the FK, and keep [CODE] as a UNIQUE INDEX (which means it is an “alternate key”). Is [ID_CODE], as PRIMARY KEY, the best option if I use [CODE] column to look up the table?
Can a clustered index be created on A varchar column?
If the values in this column will frequently change then this may not be a good candidate for creating a clustered index. In general its not a very good practice to create clustered index on varchar columns but again it depends.
Can a PK be used as a clustered key?
You can have ID_CODE as PK and (CODE_LEVEL, CODE) as clustered key. Or the other way around.