操作数据库的疑问，谢谢

[windaway]

我这样写：
public int TodayAccountNum(String username, long date ) throws SQLException, Exception
{
ResultSet rs=null;
int rs_count=0;
if (con != null)
{
try{
// create a prepared SQL statement
PreparedStatement selectacc;
selectacc = con.prepareStatement(
"SELECT * FROM useraccount WHERE username=? and userdate=? ;");
selectacc.setString(1, username);
selectacc.setLong(2, date);
rs=selectacc.executeQuery();
rs.next();
for (rs_count = 1; rs.next(); rs_count++);
// reset the cursor to the beginning
rs.close();
return(rs_count);
}
catch (SQLException sqle)
{
return (rs_count);
}
}
else
{
return (rs_count);
}
} // end of selectAccount()

在ACCESS数据库中，将表中的日期字段改成了LONG型后，数据库的select满足条件的总是0条记录，以前时间字段是字符串形式时就可以选择记录数的，这是为什么？
插入数据是也不可以了，这是为什么？谢谢

[windaway]

都去过节了吗？

[shixiaoxiang]

JDBC-ODBC桥连接方式中文SQL的解决方法！

Many people including me have encounter the boring Charset prolem in Java, esp in JDBC.
In JDBC-ODBC driver, when someone do like
...
String username = "Chinese Characters here" ;
String sqlstr = "select * from user where username = '"+ username + "'";
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
Connection conn = DriverManager.getConnection("jdbc:odbc:myDSN","uid","pwd");
Statement stmt = conn.createStatement();

ResultSet rst = stmt.executeQuery(sqlstr); // Error occurs with some syntax error

...
Solution
Key point: append some white spaces to the original sql sentence.
Use this function to preprocess your sqlstr before pass it to Statement Objects

/** This method is called to process the sql sentence for JDBC-ODBC.
* The main objective comed from the Bug(?) of sun's JDBC-ODBC driver
*/
public String makeinsertstring(String s){
if (s==null) return "";
int oldStringLen=0;
oldStringLen=s.length();
StringBuffer spaceString = new StringBuffer();
for(int i=0;i<=oldStringLen;i++)
spaceString.append(" ");
s = s + spaceString.toString();
return s;
}