MySQL5.5.21学习教程之一

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 | +----------------+