. Why use a database?
Because the use of manage data files (Excel) before, but particularly large amount of data when using Excel management, then, is more a trouble
so the introduction of a new data management software: database software
.? Dichotomous database
relational database
1. constrained
2. disk-based storage (that is, the data stored on the hard drive, persistence === floor)
typical:
MySQL the Oracle (SOEs) sqlserver (Microsoft) sqllite db2
non relational data
1. no constraint (Key ---> value)
2. memory-based storage (data will be placed into memory)
typical:
MemCache, Redis (microblogging), MongoDB
. three mySQL architecture ::
client :
Socket client, the server is connected, the transmission commands (SQL statements)
server:
Socket server, the client receives the instruction, and returns the results to the client
four MySQL installation.
Version: 5.5 5.7 the following
1. executable file:
.exe or .msi file
and click Next
2. archive
decompression, enter the directory bin
mysqld: start the service
mysql: connection server
3. The configuration environment variable
ps:
work, MySQL does not need to develop their own line of equipment, operation and maintenance of equipment or DBA
exercise, you need to manually install MySQL
Five initialization:.
Mysqld --initialise-Secure
database (folder):
table (file)
data lines (one line content file)