what is difference between uber and uberx

), Managed in a constrained form. But at the same time, it automatically creates a unique nonclustered index, with the performance and some functionality of the index. In fact, unique key constraints are constrained by unique indexes. A unique index is an index that uniquely checks a field and can set various parameters for flexibility. So when we create the uniqueness of a column, which is better to use?

What is the difference between a magnetic stripe card and a chip card? The central bank announced that the magnetic stripe card will be full chip card, chip card in the end what is the good? What

Question one: The difference between statement and PreparedStatementFirst of all, what is statement in Java:statement is an important way for Java to perform database operations to send SQL statements to the database, based on the database connection that has been established . Specific steps:1. First import java.sql.*

Tags: the comparison between make STR is SQL info strong. comNote: M here is not a specific length stored in the database, it was always mistaken for int (3) to store only 3-length numbers, and int (11) would store 11-length numbers, which is a big mistake. In fact, when we choose the type of int, whether it is int (3

this issue, this post is very good (fgetc and getc, which fast?) )。 OK, the above is the difference between fgetc and getc! However, it is important to add that the two functions are the same in GNU C, they are all implemented by functions, and then getc simply and rudely add a macro declaration

What is the difference between a H67 motherboard and a H77 motherboard? As shown below: H67 and H77 The difference is big, I want to buy a can use Ivy Bridge processor motherboard, is going to buy a new i5 3550 of the processor,

PS: What is the difference between the mask and the channel? Here we can use the concept of the mask to help understand the meaning of the channel, the usual masking can be seen as this: when you select a portion of the image on the PS image using the selection tool, the gray-black part of the selection is the mask,

"Netizen asks a question": have been not clear exactly what difference does photoelectric converter, fiber transceiver, light cat, light module have? "Answer": Optical module is inserted in the router or switch, can not be used independently, belong to other devices part. and netizens mentioned (photoelectric converter, optical transceiver, light cat, optical m

Color difference component input is a way to display signal input using color difference component port. Color Difference Port At present, in some professional video workstation/editing card professional-grade video equipment or high-end DVD players and other appliances on the see there are YUV, YcbCr, y/b-y/b

What does an OEM mean OEM Full name Original equipment manufacturer, refers to the manufacturer according to the original requirements and authorization, according to specific conditions and production. All the design drawings and so on are completely in accordance with the design of upstream manufacturers to carry out the manufacturing process, the straightforward saying is the foundry. At present, the ma

The difference between the assembly machine and the brand machine: Here is a simple talk about the difference between the brand machine and their own assembly computer. Emphasize that, at present all brand machines are assembled machines, but the brand machine is a large volume of procurement after the test, printed o