MySQL5.5.21学习教程之一
来源:程序员人生 发布时间:2015-03-06 08:11:24 阅读次数:3770次
最近做项目需要MySQL,顺便捡起好久没弄的数据库了!可能要写1个系列关于MYSQL的学习笔记,那不来与大家同享!
说到安装数据库,可真的够让人着急的!自己的系统是Windows8,安装了1圈server却没有找到最好的,工夫不负有心人。找到了mysql⑸.5.21-winx64.msi。终究成功了!
具体的安装细节请参考博客:学习数据库在win8上安装!!
show databases;
show engines;
show engines G
show variables like 'have%';
+----------------------+----------+
| Variable_name | Value |
+----------------------+----------+
| have_compress | YES |
| have_crypt | NO |
| have_csv | YES |
| have_dynamic_loading | YES |
| have_geometry | YES |
| have_innodb | YES |
| have_ndbcluster | NO |
| have_openssl | DISABLED |
| have_partitioning | YES |
| have_profiling | YES |
| have_query_cache | YES |
| have_rtree_keys | YES |
| have_ssl | DISABLED |
| have_symlink | YES |
+----------------------+----------+
show variables like 'storgae_engine%';
[mysqld]
# The TCP/IP Port the MySQL Server will listen on
port=3306
#Path to installation directory. All paths are usually resolved relative to this.
basedir="C:/Program Files/MySQL/MySQL Server 5.5/"
#Path to the database root
datadir="C:/ProgramData/MySQL/MySQL Server 5.5/Data/"
# The default character set that will be used when a new schema or table is
# created and no character set is defined
character-set-server=utf8
# The default storage engine that will be used when create new tables when
default-storage-engine=INNODB
help contents;
help Data Types;
e.g.
help TIME;
Name: 'TIME'
Description:
TIME
A time. The range is '⑻38:59:59' to '838:59:59'. MySQL displays TIME
values in 'HH:MM:SS' format, but permits assignment of values to TIME
columns using either strings or numbers.
URL: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-type-overview.html
use test;
create TABLE f_test(a FLOAT(38,30),b DECIMAL(38,30));
INSERT INTO f_test VALUES (12443.43534534543,343243.2343546534636401);
select * from f_test G
*************************** 1. row ***************************
a: 12443.435546875000000000000000000000
b: 343243.234354653463640100000000000000
1 row in set (0.00 sec)
create TABLE int_test(num INTEGER);
INSERT INTo int_test VALUES (0),(⑴),(⑴.1),(1.1),(1009888);
select * from int_test G
*************************** 1. row ***************************
num: 0
*************************** 2. row ***************************
num: ⑴
*************************** 3. row ***************************
num: ⑴
*************************** 4. row ***************************
num: 1
*************************** 5. row ***************************
num: 1009888
5 rows in set (0.00 sec)
create TABLE bit_test(id BIT(8));
#添加的第1个数字为10进制的数字,第2个数字为2进制的数据
insert into bit_test values (11),(b'11');
select id+0 from bit_test G
*************************** 1. row ***************************
id+0: 11
*************************** 2. row ***************************
id+0: 3
2 rows in set (0.00 sec)
select BIN(id+0) from bit_test G
*************************** 1. row ***************************
BIN(id+0): 1011
*************************** 2. row ***************************
BIN(id+0): 11
2 rows in set (0.28 sec)
#时间日期的插入学习
create table date_test(f_date DATE,f_datetime DATETIME,f_timestamp TIMESTAMP,f_time TIME,f_year YEAR);
select CURDATE();
+------------+
| CURDATE() |
+------------+
| 2015-01⑴4 |
+------------+
select CURDATE(),NOW(),NOW(),time(NOW()),year(NOW()) G
*************************** 1. row ***************************
CURDATE(): 2015-01⑴4
NOW(): 2015-01⑴4 19:39:56
NOW(): 2015-01⑴4 19:39:56
time(NOW()): 19:39:56
year(NOW()): 2015
1 row in set (0.00 sec)
insert into date_test values (CURDATE(),NOW(),NOW(),time(NOW()),year(NOW()));
select * from date_test G
*************************** 1. row ***************************
f_date: 2015-01⑴4
f_datetime: 2015-01⑴4 19:41:07
f_timestamp: 2015-01⑴4 19:41:07
f_time: 19:41:07
f_year: 2015
1 row in set (0.00 sec)
create TABLE user(id INTEGER,name VARCHAR(20));
insert into user values (1,'bob'),(2,'petter');
select * from user;
+------+--------+
| id | name |
+------+--------+
| 1 | bob |
| 2 | petter |
+------+--------+
show tables;
+----------------+
| Tables_in_test |
+----------------+
| bit_test |
| date_test |
| f_test |
| int_table |
| int_test |
| user |
+----------------+
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