Are you’re trying to drop a logon trigger in SQL Server, but you’re getting an error like the following?
“Cannot drop the trigger ‘trigger_name’, because it does not exist or you do not have permission.”
It could be because you’re missing the ON ALL SERVER argument.
Students learning a new programming language will often start their first lesson with an IF statement, where their statement will return a value only if the expression is true.
They might then progress to an IF... ELSE statement, where they can determine another value to return if the expression is false. So therefore, return one value if the expression is true, and another value if it’s false.
SQL Server certainly includes the IF... ELSE statement in its T-SQL toolbox.
SQL Server also includes the IIF() function, which does a similar thing, but with a more concise syntax.
But there are some subtle differences.
In SQL Server, the IIF() function (not to be confused with the IF statement) is a conditional function that returns the second or third argument based on the evaluation of the first argument.
It’s a shorthand way for writing a CASE expression. It’s logically equivalent to CASE WHEN X THEN Y ELSE Z END assuming IIF(X, Y, Z).
IIF() is an abbreviation for Immediate IF.
Most (probably all) programming languages include some form of the IF statement that allows programmers to write conditional code. That is, code that will execute only if a certain condition is true.
It’s a very simple concept. Basically it goes like this:
“If this, do that.”
Most languages simply call it IF, but some have their own twist on the name (for example, in ColdFusion/CFML, it’s called CFIF).
In any case, they essentially do the same thing.
In SQL Server (or more precisely, its programming language T-SQL) it’s called IF.
In SQL Server, you can use the WAITFOR statement to delay the execution of a batch, stored procedure, or transaction.
It works similar to MySQL‘s sleep() function.
Actually, it’s probably more like a combination of Postgres‘s three “sleep” functions: pg_sleep(), pg_sleep_for(), and pg_sleep_until().
I say this, because SQL Server’s WAITFOR statement gives you the option of specifying either a time delay, or an actual fixed time before execution continues.
In SQL Server, you can use GOTO to alter the flow of execution. You can use it to “jump” to another part in the T-SQL code.
The way it works is, you create a label, then you can use GOTO to jump to that label. Any code between GOTO and the label are skipped, and processing continues at the label.
GOTO statements and labels can be used anywhere within a procedure, batch, or statement block. They can also be nested.
In SQL Server the sys.sql_modules, sys.system_sql_modules, and sys.all_sql_modules system catalog views return metadata about SQL language-defined modules in SQL Server.
However, there is a difference between them.
When you create a temporary table in SQL Server, you have the option of making it a local or global temporary table.
Here’s a quick outline of the main differences between local temporary tables and global temporary tables.
In SQL Server, you can use any of the following five ways to return a list of temporary tables using Transact-SQL.
These return both local and global temporary tables.
In SQL Server you can create a temporary table based on another table by using the SELECT... INTO syntax.
You can create the table with or without data. In other words, you can copy data from the original table if you wish, or you can create the table without any data.