java ejb開發 程序4、語句alter table people add(phone_number varchar2(10)) 的作用是 A 修改表結構 B 為people表添加約束,約束名稱是phone_number C 向people表中添加一列,名稱是phone_number,數據類型是varchar2,長度是10 D 上述答案均不正確 5、( )BLOB和CLOB的區別在于 A CLOB只能存放字符類型的數據,而BLOB沒有任何限制 B BLOB只能存放字符類型的數據,而CLOB沒有任何限制 C CLOB只能存放小于4000字節的數據,而BLOB可以存放大于4000字節的數據 D BLOB只能存放小于4000字節的數據,而CLOB可以存放大于4000字節的數據 6、存儲過程從本質上來講就是 A 匿名的PL/SQL程序塊,它可以被賦予參數 B 命名的PL/SQL程序塊,它可以被賦予參數 C 命名的PL/SQL程序塊,不能被賦予參數 D 匿名的PL/SQL程序塊,不能被賦予參數 7、( )下列關于日期數據類型,哪一個語句是正確的寫法 A insert into test values( 9999-12-03 ) B insert into test values( 1999-03-02 ) C insert into test values(to_char(1999-06-03, yyyy/dd/mm )) D insert into test
This project attempts to implement a Database using B+Tree. The project has developed a DATABASE SYSTEM with lesser memory consumption. Its API includes simple SQL Statements and the output is displayed on the screen. Certain applications for which several features of existing databases like concurrency control, transaction management, security features are not enabled. B+Trees can be used as an index for factor access to the data. Help facility is provided to know the syntax of SQL Statements.
About:
hamsterdb is a database engine written in ANSI C. It supports a B+Tree index structure, uses memory mapped I/O (if available), supports cursors, and can create in-memory databases.
Release focus: Major feature enhancements
Changes:
This release comes with many changes and new features. It can manage multiple databases in one file. A new flag (HAM_LOCK_EXCLUSIVE) places an exclusive lock on the file. hamsterdb was ported to Windows CE, and the Solution file for Visual Studio 2005 now supports builds for x64. Several minor bugs were fixed, performance was improved, and small API changes occurred. Pre-built libraries for Windows (32-bit and 64-bit) are available for download.
Author:
cruppstahl
結合單片機和M a t l a b 兩者的優點,基于事件驅動的中斷通信機制,提出一種Matlab 環境下PC 機與
單片機實時串行通信及數據處理的方法;完成單片機數據采集系統與PC 機的RS-232/RS-485 串行通
信及其通信數據的分析處理、文件存儲、F I R 濾波及圖形顯示;簡化系統開發流程,提高開發效率。
該方法已成功應用于一個P I C 1 6 F 8 7 6 單片機應用系統實例之中