SybaseJDBC
1.单用一个JSP文件测试SYBASE jconnect-5_2 JDBC数据库接口:
"+rs.getString("emp_lname")+" | ");"+rs.getString("dept_id")+" | ");"+rs.getString("street")+" | ");"+rs.getString("city")+" | ");"+rs.getString("state")+" |
rs.close();
stmt.close();
conn.close();
%>
2.再用JSP和Java Bean的方法:
JSP Code:
ResultSet rs=sybase.Query("select * from tjck_dh");
while(rs.next()) {
out.print("|"+rs.getString("name")+"|");
out.print(rs.getString("card_no")+"|");
out.print(rs.getString("amount")+"|");
out.print(rs.getString("home_call")+"|");
out.print(rs.getString("office_call")+"|
");
}
rs.close();
%>
Bean的代码:
package test;
import java.sql.*;
public class sybconn {
// String sDBDriver = "com.sybase.jdbc2.jdbc.SybDriver";
String sConnStr = "jdbc:sybase:Tds:localhost:2638";
// String user="dba";
// String passwd="sql";
Connection conn = null;
ResultSet rs = null;
public ResultSet Query(String sql) throws SQLException,Exception {
Class.forName("com.sybase.jdbc2.jdbc.SybDriver").newInstance();
conn = DriverManager.getConnection(sConnStr,"dba","sql");
Statement stmt = conn.createStatement();
rs = stmt.executeQuery(sql);
return rs;
}
}
3.利用JDBC(SYBAE jconnect-5_2)查询Sybase ASA7.0中数据的图形化Java程序范例:
//
// 一个简单的利用JDBC(SYBAE jconnect-5_2)查询Sybase ASA7.0中数据的图形化Java程序范例
// 执行的SQL语句是" select * from employee " ,可以改成自己所需的.
// 运行方式为: c:\> java JDBCTest
//
import java.awt.*;
import java.sql.*; // 在使用JDBC之前,必须引入JAVA的SQL包
class JDBCTest extends Frame {
TextArea myTextArea;
public JDBCTest () {
//设定程序的显示界面
super("一个简单的利用JDBC(jconnect-5_2)查询Sybase ASA7.0中数据的图形化Java程序范例");
setLayout(new FlowLayout());
myTextArea = new TextArea(30,80);
add(myTextArea);
resize(500,500);
show();
myTextArea.appendText("数据库查询中,请等待......\n");
}
void displayResults(ResultSet results) throws SQLException {
//首先得到查询结果的信息
ResultSetMetaData resultsMetaData = results.getMetaData();
int cols = resultsMetaData.getColumnCount();
//将等待信息清除
myTextArea.setText("");
//显示结果
while(results.next()) {
for(int i=1;iif(i>1)
myTextArea.appendText("\t");
try{
myTextArea.appendText(results.getString(i));
}
// 捕获空值时产生的异常
catch(NullPointerException e){
}
}
myTextArea.appendText("\n");
}
}
public boolean handleEvent(Event evt) {
if (evt.id == Event.WINDOW_DESTROY) {
System.exit(0);
return true;
}
return super.handleEvent(evt);
}
public static void main(String argv[]) throws SQLException,Exception {
//设定查询字串
String queryString = "select * from employee";
JDBCTest myJDBCTest = new JDBCTest();
//加载驱动程序
Class.forName("com.sybase.jdbc2.jdbc.SybDriver").newInstance();
//建立连接,localhost为主机名,dba为用户名,sql为密码
Connection myConn = DriverManager.getConnection("jdbc:sybase:Tds:localhost:2638","dba","sql");
Statement myStmt = myConn.createStatement();
//执行查询
ResultSet myResults = myStmt.executeQuery(queryString);
myJDBCTest.displayResults(myResults);
//关闭所有打开的资源
myResults.close();
myStmt.close();
myConn.close();
}
}

InnoDBBufferPool reduces disk I/O by caching data and indexing pages, improving database performance. Its working principle includes: 1. Data reading: Read data from BufferPool; 2. Data writing: After modifying the data, write to BufferPool and refresh it to disk regularly; 3. Cache management: Use the LRU algorithm to manage cache pages; 4. Reading mechanism: Load adjacent data pages in advance. By sizing the BufferPool and using multiple instances, database performance can be optimized.

Compared with other programming languages, MySQL is mainly used to store and manage data, while other languages such as Python, Java, and C are used for logical processing and application development. MySQL is known for its high performance, scalability and cross-platform support, suitable for data management needs, while other languages have advantages in their respective fields such as data analytics, enterprise applications, and system programming.

MySQL is worth learning because it is a powerful open source database management system suitable for data storage, management and analysis. 1) MySQL is a relational database that uses SQL to operate data and is suitable for structured data management. 2) The SQL language is the key to interacting with MySQL and supports CRUD operations. 3) The working principle of MySQL includes client/server architecture, storage engine and query optimizer. 4) Basic usage includes creating databases and tables, and advanced usage involves joining tables using JOIN. 5) Common errors include syntax errors and permission issues, and debugging skills include checking syntax and using EXPLAIN commands. 6) Performance optimization involves the use of indexes, optimization of SQL statements and regular maintenance of databases.

MySQL is suitable for beginners to learn database skills. 1. Install MySQL server and client tools. 2. Understand basic SQL queries, such as SELECT. 3. Master data operations: create tables, insert, update, and delete data. 4. Learn advanced skills: subquery and window functions. 5. Debugging and optimization: Check syntax, use indexes, avoid SELECT*, and use LIMIT.

MySQL efficiently manages structured data through table structure and SQL query, and implements inter-table relationships through foreign keys. 1. Define the data format and type when creating a table. 2. Use foreign keys to establish relationships between tables. 3. Improve performance through indexing and query optimization. 4. Regularly backup and monitor databases to ensure data security and performance optimization.

MySQL is an open source relational database management system that is widely used in Web development. Its key features include: 1. Supports multiple storage engines, such as InnoDB and MyISAM, suitable for different scenarios; 2. Provides master-slave replication functions to facilitate load balancing and data backup; 3. Improve query efficiency through query optimization and index use.

SQL is used to interact with MySQL database to realize data addition, deletion, modification, inspection and database design. 1) SQL performs data operations through SELECT, INSERT, UPDATE, DELETE statements; 2) Use CREATE, ALTER, DROP statements for database design and management; 3) Complex queries and data analysis are implemented through SQL to improve business decision-making efficiency.

The basic operations of MySQL include creating databases, tables, and using SQL to perform CRUD operations on data. 1. Create a database: CREATEDATABASEmy_first_db; 2. Create a table: CREATETABLEbooks(idINTAUTO_INCREMENTPRIMARYKEY, titleVARCHAR(100)NOTNULL, authorVARCHAR(100)NOTNULL, published_yearINT); 3. Insert data: INSERTINTObooks(title, author, published_year)VA


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