如何用Java实现数据库查询

import java.sql.*

public class MSSQLText

{

public static void main(String args[])

{

String url="jdbc:microsoft:sqlserver://localhost:1433DatabaseName=Northwind"

String user="sa"//这里替换成你自已的数据库用户名

String password="sa"//这里替换成你自已的数据库用户密码

String sqlStr="select CustomerID, CompanyName, ContactName from Customers"

try

{ //这里的异常处理语句是必需的.否则不能通过编译!

Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver")

System.out.println("类实例化成功!")

Connection con = DriverManager.getConnection(url,user,password)

System.out.println("创建连接对像成功!")

Statement st = con.createStatement()

System.out.println("创建Statement成功!")

ResultSet rs = st.executeQuery(sqlStr)

System.out.println(" *** 作数据表成功!")

System.out.println("----------------!")

while(rs.next())

{

System.out.print(rs.getString("CustomerID") + "")

System.out.print(rs.getString("CompanyName") + "")

System.out.println(rs.getString("ContactName"))

}

rs.close()

st.close()

con.close()

}

catch(Exception err){

err.printStackTrace(System.out)

}

}

}

1.增加\x0d\x0aString s1="insert into tableNames (id,name,password) values(myseq.nextval,?,?)"\x0d\x0aClass.forName(driver)\x0d\x0aConnection conn = DriverManager.getConnection(url,dbUser,dbPwd)\x0d\x0aPreparedStatement prepStmt = conn.prepareStatement(s1)\x0d\x0aprepStmt.setString(1,name)\x0d\x0aprepStmt.setString(2,password)\x0d\x0aResultSet rs=stmt.executeUpdate()\x0d\x0a2、删除\x0d\x0aString s2="delete from tbNames where name=?"\x0d\x0aClass.forName(driver)\x0d\x0aConnection conn = DriverManager.getConnection(url,dbUser,dbPwd)\x0d\x0aPreparedStatement prepStmt = conn.prepareStatement(s2)\x0d\x0aprepStmt.setString(1,name)\x0d\x0aResultSet rs=stmt.executeUpdate()\x0d\x0a3、修改\x0d\x0aString s3=“update tbNames set name=? where id=?”\x0d\x0aClass.forName(driver)\x0d\x0aConnection conn = DriverManager.getConnection(url,dbUser,dbPwd)\x0d\x0aPreparedStatement prepStmt = conn.prepareStatement(s3)\x0d\x0aprepStmt.setString(1,name)\x0d\x0aprepStmt.setString(2,id)\x0d\x0aResultSet rs=stmt.executeUpdate()\x0d\x0a4、查询\x0d\x0aString s4="select id,name,password from tbNames"\x0d\x0aClass.forName(driver)\x0d\x0aConnection conn = DriverManager.getConnection(url,dbUser,dbPwd)\x0d\x0aStatement stmt=conn.createStatement()\x0d\x0aResultSet rs = stmt.executeQuery(s4)\x0d\x0awhile(rs.next){\x0d\x0aint id=rs.getInt(1)\x0d\x0aString name = rs.getString(2)\x0d\x0aString pwd=rs.getString(3)\x0d\x0aSystem.out.println(id+name+pwd)} \x0d\x0a\x0d\x0a以上四步必须都得关闭连接；！！！\x0d\x0ars.close()\x0d\x0astmt.close()\x0d\x0aconn.close()

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