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 ?
Structured Query Language (SQL) is the set of statements with which all programs and users access data in an Oracle database.
Define column constraints for different constraint types. Constraint types include PRIMARY KEY, UNIQUE, and CHECK. For details, see Defining Table Constraints. Define table index information, such as the index name and access mode. For details, see Defining an Index. On the SQL Preview tab, you...
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. ...
SQL Server 2005 permits users add non-key columns to leaf level of the non clustered index for by passing existing index key limits and to execute fully covered index queries. When the primary key and unique constraints of a table column are defined an automatic index is created. ...
Group Level Constraints TMS enforces the following additional constraints for group levels. A level can be linked to a group level or a sublevel within it, but not to both. If two group levels are linked, none of the sublevels can be linked directly to sublevels in the other group. A ...
When processing the configuration tree, the processor assumes that the top level array key (which matches the extension name) is already stripped off. This work, including the code samples, is licensed under aCreative Commons BY-SA 3.0license....