Int
(1). 4 byte storage, the length of the int is 4 bytes, the storage space is less than datatime, the int index storage space is also relatively small, the sorting and the query efficiency is relatively higher a little(2) The readability is
usually storage time with datetime type, and now many systems also use int storage time, what difference do they have? Individuals prefer to use int this is good for date calculations, so let's look at the kind of things that would be better. int(1).
Turn from:datetime vs. timestamp in MySQLSame1. DisplayThe timestamp column is displayed in the same format as the datetime column. In other words, the display width is fixed at 19 characters, and the format is Yyyy-mm-dd HH:MM:SS.Different1.
Problem Description:Requires storage of 13-bit millisecond-level timestamps, formatted as INT (13) in MySQL, overflow, auto-truncated to 2147483647Analysis:If you ask directly the scope of the int type of storage, it must be known, but the addition
DB2 Vs MySQL series | comparison of data types between MySQL and DB2, db2mysql
As MySQL Databases become more and more widely used, there are more and more demands for migration from DB2 to MySQL databases. During database migration, the first
Since the introduction of the relational database model by edugatd in 1970, relational databases began to emerge. After more than 40 years of evolution, today's relational databases have a wide variety of features and are widely used. In the face of
* Operation of the library (increase and deletion check)I. System databaseView system library commands show databases1.information_schema:Virtual library, does not occupy disk space, storage is the database startup parameters, such as user table
Differences between MySQL and SQL Server
1. mysql supports enum, set, and SQL server.2. mysql does not support nchar, nvarchar, and ntext3. the incremental Statement of mysql is AUTO_INCREMENT, while that of mssql is identity)4. mssql by default,
Database overviewWhat is DataSymbolic records describing things are called dataWhat is a databaseThe database is the warehouse where the data is stored, except that the warehouse is on a computer storage device, and the data is stored in a certain
Brief introduction:Description: This module is primarily used to map a relational database table to a class of py, the row maps to an instance of the Py class, and the column maps to the properties of the Py instance, because it is compatible with
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