Summary for week2

July 19th
 1:30pm
 H2DB memory database
  2:00pm
 email-writing should be simple and clear. 
 Tell most important thing firstly.
 Structure: opeing (purpose or action), body(detail), close(follow-up or gratitude)

 3:30pm
 database schema design

July 20th
 1:30pm
 API stream: STAX can be used to read file.
 Use executor or thread.

July 21st:
 Recursive traverse items.
 Use KeyHolder to return key.
 Use updateBatch to improve performance.

July 22nd
 CODE + DOCS = SOLID INPUT
 Night:
  Mysql test sql statements. Pay attention to DateTime, Duration and so on.
 Configure database in config.xml.

July 23rd
 Night summary
 Database design.
 Use sybase to store, we can use other tools to get direct sql executed.
 Dont forget to grant permission for others to visit tables.
  commands like sp_help.

==================================常用DDL语句===========================================
Sybase中DDL语句不能修改字段的数据类型，只能修改空与非空： 
1.删除列： 
ALTER TABLE table_name DELETE column_name; 2.增加列： ALTER TABLE table_name ADD (column_name DATA_TYPE [NOT] NULL); 3.修改列的空与非空： ALTER TABLE table_name MODIFY column_name [NOT] NULL; 4.修改列名： ALTER TABLE table_name RENAME old_column_name TO new_column_name; 5.快速建立临时表： SELECT * INTO [#]table_name FROM .....; 6、修改表名： ALTER TABLE old_table_name RENAME new_table_name 7.增加主键约束： ALTER TABLE tb_name ADD CONSTRAINT pk_name PRIMARY KEY(col_name,..) 8.删除主键约束： ALTER TABLE tb_name DROP CONSTRAINT pk_name; 9.建立自增长字段，与Oracle的SEQUENCE类似： CREATE TABLE TMP_001 (RES_ID INTEGER IDENTITY NOT NULL); 10.添加表注释： COMMENT ON TABLE table_name IS '....'; 11.创建索引： CREATE INDEX index_name ON table_name(column_name);

  Use queue to get sth

 Bug fix:
 default value should be valid.
 setXXX should be specific.
 pay attention to each detail.

 Night:
 JDBC template seems to be more useful for query not for update.
 Insert into database timestamp.

July 24th
 1:30pm
 Transaction: try {commit();} catch(){rollback();} finnaly{clean connection rsc}
 JPA wrap object to db.
 Junit test codes.
 Weeklist should be objective and seems to move to the right direction.
 Excel and tableau

 Night:
 Summary for whole week.
 Some Tips:
 Dont worry, take it easy. You will get used to it, and just be confident and careful.