DOT NET Interview Questions - DotNetSpider

UNION SQL syntax is used to select information from two tables.But it selects only
distinct records from both the table. , while UNION ALL selects all records from both
the tables.
Note :- Selected records should have same datatype or else the syntax will not work.
(I)How can you raise custom errors from stored
procedure ?
The RAISERROR statement is used to produce an ad hoc error message or to retrieve a
custom message that is stored in the sysmessages table. You can use this statement with
the error handling code presented in the previous section to implement custom error
messages in your applications. The syntax of the statement is shown here.
RAISERROR ({msg_id |msg_str }{,severity ,state }
[ ,argument [ ,,...n ] ] ))
[ WITH option [ ,,...n ] ]
A description of the components of the statement follows.
msg_id :-The ID for an error message, which is stored in the error column in sysmessages.
msg_str :-A custom message that is not contained in sysmessages.
severity :- The severity level associated with the error. The valid values are 0–25. Severity
levels 0–18 can be used by any user, but 19–25 are only available to members of the
fixed-server role sysadmin. When levels 19–25 are used, the WITH LOG option is required.
state A value that indicates the invocation state of the error. The valid values are 0–127.
This value is not used by SQL Server.
Argument, . . .
One or more variables that are used to customize the message. For example, you could
pass the current process ID (@@SPID) so it could be displayed in the message.
WITH option, . . .
The three values that can be used with this optional argument are described here.
LOG - Forces the error to logged in the SQL Server error log and the NT application log.
NOWAIT - Sends the message immediately to the client.
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