Updated mysqli version: if ($result = $mysqli->query(“SHOW TABLES LIKE ‘”.$table.”‘”)) { if($result->num_rows == 1) { echo “Table exists”; } } else { echo “Table does not exist”; } Original mysql version: if(mysql_num_rows(mysql_query(“SHOW TABLES LIKE ‘”.$table.”‘”))==1) echo “Table exists”; else echo “Table does not exist”; Referenced from the PHP docs.
Yes, MySQL (indeed all database systems as far as I’m aware) will stop processing when a row is returned when using an Exists function. You can read more at the MySQL documentation: If a subquery returns any rows at all, EXISTS subquery is TRUE.
To check for the existence of a directory using Dir, you need to specify vbDirectory as the second argument, as in something like: If Dir(“C:\2013 Recieved Schedules” & “\” & client, vbDirectory) = “” Then Note that, with vbDirectory, Dir will return a non-empty string if the specified path already exists as a directory or … Read more
In Terraform, you’re required to decide explicitly what system is responsible for the management of a particular object, and conversely which systems are just consuming an existing object. There is no way to make that decision dynamically, because that would make the result non-deterministic and — for objects managed by Terraform — make it unclear … Read more
Try this Not Any pattern. var query = db.table1 .Where(t1 => !db.table2 .Any(t2 => t2.cat == t1.cat && t2.julianDte < t1.julianDte) );
Here’s how I usually do it: Just replace your query with this statement SELECT * FROM table WHERE 1 SELECT CASE WHEN EXISTS ( SELECT * FROM table WHERE 1 ) THEN ‘TRUE’ ELSE ‘FALSE’ END
something like this best to use a workbook variable to provide further control (if needed) of the opened workbook updated to test that file name was an actual workbook – which also makes the initial check redundant, other than to message the user than the Textbox is blank Dim strFile As String Dim WB As … Read more
Yes it stops execution so this is generally preferable to HAVING COUNT(*) > 0 which often won’t. With EXISTS if you look at the execution plan you will see that the actual number of rows coming out of table1 will not be more than 1 irrespective of number of matching records. In some circumstances SQL … Read more
I believe file_exists does work with relative paths, though you could also try something along these lines… if(!@include(“script.php”)) throw new Exception(“Failed to include ‘script.php'”); … needless to say, you may substitute the exception for any error handling method of your choosing. The idea here is that the if-statement verifies whether the file could be included, … Read more