Learn the benefits of unique primary keys, basic table creation, and the use of identity and primary key constraints for efficient SQL database management.
Although this is useful when we want to put a unique constraint on a single column, sometimes we may want to add unique constraints on a composite key, which is a combination of columns. To define a composite unique key, we can use table constraints. We’ll discuss that in the next sec...
Check constraints or partition function of source table ALTER TABLE with variable TableName ALTER vs UPDATE when creating a new column with default value. Alternate queries for MERGE Alternative for OR in WHERE clause Alternative for PIVOT Alternative of CURSOR in SQL to improve performance ?
In this tutorial you will learn about Defining Indexes in SQL Server 2005 – clustered and non clustered indexex, The Query Optimizer, to create an index, To create a unique index, To create a clustered index, To create full-text indexes, To change index properties, To rename an index, t...
Structured Query Language (SQL) is the set of statements with which all programs and users access data in an Oracle database.
Constraints Managing Indexes Creating a Partitioned Table Managing Table Data Editing Temporary Tables Creating a Foreign Table View Management Sequence Management Users/Roles SQL Terminal Management Security Management Troubleshooting FAQs GDS DSC DataCheck DWS-Connector Server Tools API Reference SDK ...
They are also used in NDB Cluster to handle uniqueness constraints. Currently, the only partitioning algorithm is hashing and ordered indexes are local to each node. Thus, ordered indexes cannot be used to handle uniqueness constraints in the general case. ...
They are also used in NDB Cluster to handle uniqueness constraints. Currently, the only partitioning algorithm is hashing and ordered indexes are local to each node. Thus, ordered indexes cannot be used to handle uniqueness constraints in the general case. ...
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Current MS documentation of SQL Server's CHECK Constraints gives a nice example of a sort of similar function and the problem that's caused if you try to require row counts to be non-zero (if you don't have any rows there are no rows with counts that are n...