null printer

PHP is a loosely typed programming language, and it is an indispensable step in a function to examine the "type" of the passed parameter value and whether the value is null or NULL. Type check Starting with PHP5, PHP allows type constraints on the parameters of a function, that is, the type of the parameter can be constrained to an object, an interface, an array (starting with PHP 5.1), or cal

In fact, there is nothing to say about this problem, today's optimization encountered an SQL statement, because it is more interesting, so I intercepted, simplified the SQL statement, to show you, as shown belowDECLARE @bamboo_Code varchar (3);Set @bamboo_Code = '-01 ';SELECT DISTINCT Yarn_lotFrom Dbo.rsjob with (NOLOCK)WHERE Right (ges_no, 3) = @bamboo_CodeAs shown above, the SQL column Yarn_log uses the IsNull (Yarn_lot, ') Table Rsjob is a heap table that has an index yarn_lot on the column y

1, adjust the background settings In the process of using the spray, we sometimes find that the printer's output speed significantly slower than before; in the case of excluding the printer itself, there is a sudden slowdown in the phenomenon, it is likely that the background settings for the printer has been unintentionally modified; At this point, we might as well in the system's Start menu, sequentially

In Oracle, a keyword is NULL, indicating that a value is unknown and uncertain. Since it is unknown, there are several possibilities. Therefore, NULL is not a definite In Oracle, a keyword is NULL, indicating that a value is unknown and uncertain. Since it is unknown, there are several possibilities. Therefore, NULL is

MySQL database is an open source database based on structured data. SQL statements are the core language of MySQL databases. However, when executing SQL statements in the MySQL database, you need to be careful with two traps. Trap 1: NULL values are not necessarily empty A null value is a special field. In MySQL databases, null values often have different meaning

In sqlserver 2000, the null value of datetime is the default value 00:00:00. in C #, the null value of datetime is the minimum value 0001-01-01 00:00:00. For database insertion, the date value updated to a null value is somewhat less than expected. For example, I inserted a null value. I also took out a

I encountered a strange problem in a project, and it took me a lot of time to solve it. The final debugging found that it was a judgment problem-about 0 and ''(null single quotes, for better understanding, I added a space), I found that 0 = "was actually true, depressed at the same time decided to write a simple page test, swear to 0, null, empty, the relationship between

public static bool Print (int orderId, string ordertime) {bool b = true; String cut = ((char) 29). ToString () + ((char) 86). ToString () + ((char) 1). ToString () + ((char) 49). ToString ();//Send paper cut instruction//byte[] Byte_cut = System.Text.Encoding.Default.GetBytes (cut); string font = ((char) 1D). ToString () + ((char) 21). ToString () + ((char) 01). ToString () + ((char) 10). ToString ();//Text size byte[] fonts = new byte[] {2, 0};//1d 21 Select font byte[] temp = new by

How to connect to a network printer in win7 The company recently rented a Konica Minolta C250 network printer to connect, and the boss also had a laptop. When connecting to the printer, pay attention to some details to connect to the printer normally. Ensure that the printer