I’ll explain this by using examples in DDL, using SQL Server syntax. The short version of this is fairly simple. Every table that you want to use in relations should have a primary key constraint; this can eit
How do SQL constraints help a Microsoft SQL Server database application? Solution A constraint is a rule in a relational database that you create to make sure that data stored in a table adheres to specific standards that you set, such as always making sure there is a value in a particul...
Resumable add table constraints Supports pausing and resuming an ALTER TABLE ADD CONSTRAINT operation. Resume such operation after maintenance windows, failovers, or system failures. CREATE INDEX WAIT_AT_LOW_PRIORITY with online index operations clause added. Transactional replication Peer-to-peer replica...
they return a single value, orNULLin case no value was found. And this is the trap: normally, you don’t know if a subquery returnedNULLbecause it found it in a table, or because it found nothing.
Does distinct apply to all columns? Yes,DISTINCT works on all combinations of column values for all columnsin the SELECT clause. Can I use distinct with multiple columns in SQL? Answer.Yes, the DISTINCT clause can be applied to any valid SELECT query. It is important to note that DISTINCT...
After IIS deployment can not connect to SQL SERVER 2008 EXPRESS after response.write ,how to execute Response.Redirect(Request.RawUrl) ajax call does not sent cookies to web api ( Very Strange issue in Web Api) Ajax request SQL Server alert after kendo grid load alert box after response.end...
Shared users and grants are stored in the ndb_sql_metadata table, which ndb_restore by default does not restore in NDB 8.0; you can specify the --include-stored-grants option to cause it to do so. See Section 6.13, “Privilege Synchronization and NDB_STORED_USER”, for more information...
Views function as virtual tables that do not store data physically, and MySQL does not support materialized views. Views created with simple SQLs can be updated, while those created with complex SQLs cannot. PostgreSQL supports views that operate similarly to those in MySQL. Simple ...
How does SQL work? Which PL or SQL command activates a cursor? Why SQL is not a programming language? What kind of programming language is SQL? What is a RDBMS database? What is a constraint in database? What is a where clause in database management? 1. Write a CREATE VIEW statement...
LOGIN: Can this role be used to log in to the database server? SUPERUSER: Is this role a superuser? CREATEDB: Can this role create databases? CREATEROLE: Can this role create new roles? REPLICATION: Can this role initiate streaming replication? PASSWORD: Does this role requir...