我有我將使用從JSF表單數據插入到Oracle中的Java方法:如何優化此更新SQL查詢
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;
}
現在我無法測試SQL查詢。你能告訴我它是否有效,以及如何優化SQL查詢的性能?
在這種情況下,使用StringBuilder會對性能產生負面影響:連接字符串文字作爲一個大字符串保存在類文件中,而StringBuilder調用將在運行時執行。 – MvG 2012-07-26 12:19:38
即使字符串程序集在運行時完成,Java編譯器也會生成使用StringBuilder的代碼。 – 2012-07-26 12:22:30