mysql uniqueidentifier

First, what is the primary key, foreign key:There are several attributes in a record in a relational database, which can be a primary key if one of the attribute groups (note is a group) uniquely identifies a record:Student Table (School number,

Correspondence between data types in SQL Server and data types in MySQL (EXT): 78899477One, SQL Server and MySQL data storage differences1, datetime in SQL Server, reserved to microseconds (the second decimal point 3 bits), and MySQL only retained

(Transferred from: http://blog.csdn.net/maonongwu/article/details/6327093)GUID IntroductionGUID (Global unique identifier) Globally unique identifier, which is a 16-byte binary value generated by the identity number on the network card (each network

How to write a statement can update hundreds of MySQL data! Need to test MySQL database, there is a database of tens of thousands of data, how to write a PHP file each time update hundreds of information, I am writing a cycle update a message, so I

1:java data type and MySQL data type comparison table Type name Display length Database type Java type JDBC Type index (int) VARCHAR L+n VARCHAR Java.lang.String 12

UUID and guid UUID is a string generated after the 32-byte string is separated by four hyphens (-), with a total length of 36 bytes. For example: 550e8400-e29b-41d4-a716-446655440000 Http://gohands.blogbus.com/logs/147479174.html GUID is

Data type Type Description Bit Integral type The bit data type is integral, and its value can only be 0, 1, or null. This data type is used to store data with only two possible values,

Data types and scopes used by Microsoft Access, MySQL, and SQL Server.Microsoft Access Data type Data Type Description Storage Text Used for text or a combination of text and numbers. A maximum of 255

Mysql database Chinese-English comparison table bitsCN.com -- Sentence skill-- Data operationsSELECT -- retrieve data rows and columns from database tablesINSERT -- add new data rows to the database tableDELETE -- DELETE data rows from a database

Mysql data format: bitsCN.com Varchar occupies 2 bytes for each English (ASCII) character, and only two bytes for one Chinese characterChar occupies 1 byte for English (ASCII) characters, and the type of Varchar that occupies 2 bytes for a Chinese