我有我将使用从JSF表单数据插入到Oracle中的Java方法:如何优化此更新SQL查询
public int saveData(int result) throws SQLException, java.text.ParseException, NoSuchAlgorithmException {
String SqlStatement = null;
if (ds == null) {
throw new SQLException();
}
Connection conn = ds.getConnection();
if (conn == null) {
throw new SQLException();
}
PreparedStatement ps = null;
/*
CREATE TABLE USERS(
USERID INTEGER NOT NULL,
GROUPID INTEGER,
SPECIALNUMBER VARCHAR2(60),
USERNAME VARCHAR2(50),
PASSWD VARCHAR2(50),
DATETOCHANGEPASSWD DATE,
ADDRESS VARCHAR2(60),
STATEREGION VARCHAR2(50),
COUNTRY VARCHAR2(50),
USERSTATUS VARCHAR2(30),
TELEPHONE VARCHAR2(50),
DATEUSERADDED DATE,
USEREXPIREDATE DATE,
DATEUSERLOCKED CHAR(20),
CITY VARCHAR2(50),
EMAIL VARCHAR2(50),
DESCRIPTION CLOB
)
/
*/
try {
conn.setAutoCommit(false);
boolean committed = false;
try { /* insert into Oracle the default system(Linux) time */
InsertSqlStatement = "INSERT INTO USERS"
+ " (USERID, GROUPID, SPECIALNUMBER, USERNAME, PASSWD, DATETOCHANGEPASSWD,"
+ " ADDRESS, STATEREGION, COUNTRY, USERSTATUS, TELEPHONE, DATEUSERADDED,"
+ " USEREXPIREDATE, DATEUSERLOCKED, CITY, EMAIL, DESCRIPTION)"
+ " VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)";
UpdateSqlStatement = "UPDATE USERS "
+ "SET "
+ "USERID = ?, "
+ "GROUPID = ?, "
+ "SPECIALNUMBER = ?, "
+ "USERNAME = ?, "
+ "PASSWD = ?, "
+ "DATETOCHANGEPASSWD = ?, "
+ "ADDRESS = ?, "
+ "STATEREGION = ?, "
+ "COUNTRY = ?, "
+ "USERSTATUS = ?, "
+ "TELEPHONE = ?, "
+ "DATEUSERADDED = ?, "
+ "USEREXPIREDATE = ?, "
+ "DATEUSERLOCKED = ?, "
+ "CITY = ?, "
+ "EMAIL = ?, "
+ "DESCRIPTION = ? "
+ "WHERE USERID = " + id;
ps = conn.prepareStatement(SqlStatement);
ps.setString(1, settingsMap.get("USERID"));
ps.setString(2, settingsMap.get("GROUPID"));
ps.setString(3, settingsMap.get("SPECIALNUMBER"));
ps.setString(4, settingsMap.get("USERNAME"));
ps.setString(5, passwdConvert(settingsMap.get("PASSWD")));
ps.setDate(6, toDate(settingsMap.get("DATETOCHANGEPASSWD")));
ps.setString(7, settingsMap.get("ADDRESS"));
ps.setString(8, settingsMap.get("STATEREGION"));
ps.setString(9, settingsMap.get("COUNTRY"));
ps.setString(10, settingsMap.get("USERSTATUS"));
ps.setString(11, settingsMap.get("TELEPHONE"));
ps.setDate(12, toDate(settingsMap.get("DATEUSERADDED")));
ps.setDate(13, toDate(settingsMap.get("USEREXPIREDATE")));
ps.setDate(14, toDate(settingsMap.get("DATEUSERLOCKED")));
ps.setString(15, settingsMap.get("CITY"));
ps.setString(16, settingsMap.get("EMAIL"));
ps.setString(17, settingsMap.get("DESCRIPTION"));
ps.executeUpdate();
conn.commit();
committed = true;
}
finally
{
if (!committed) {
conn.rollback();
}
}
} finally {
/* Release the resources */
ps.close();
conn.close();
}
return result;
}
现在我无法测试SQL查询。你能告诉我它是否有效,以及如何优化SQL查询的性能?
在这种情况下,使用StringBuilder会对性能产生负面影响:连接字符串文字作为一个大字符串保存在类文件中,而StringBuilder调用将在运行时执行。 – MvG 2012-07-26 12:19:38
即使字符串程序集在运行时完成,Java编译器也会生成使用StringBuilder的代码。 – 2012-07-26 12:22:30