本文是小小的总结一下本人开发时要在sybase数据库上创建特定的触发器
创建的触发器完成的功能如下：
在数据库中指定的表上创建插入，更新，删除触发器，当指定的表发生插入、更新或者删除操作时，将触发触发器相应的动作，触发器的作用就是，将发生上述操作的表的表名、主键名、对应的主键值、相应的操作存到另一张记录表中。本总结中除了创建该类型触发器外还包括删除触发器，删除记录表，判断是否已有记录表。
需要导入的架包：activejdbc.jar,jconn3.jar:
import java.util.List;
import java.util.Map;
import org.javalite.activejdbc.Base;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* 模板类
* @author ywnwa
*
*/
public abstract class AbstractTriggerManager implements TriggerManager {
protected static final String TRIGGER_EVENT_TABLE_NAME = "TRIGGER_EVENTS";
private final Logger logger = LoggerFactory
.getLogger(getClass());
private final String user;
private final String password;
public AbstractTriggerManager(String user, String password) {
this.user = user;
this.password = password;
}
public void openDatabase() {
Base.open(getDriverClass(), getUrl(), this.user, this.password);
logger.debug("open database sucessfuly!");
}
public void closeDatabase() {
Base.close();
logger.debug("close database sucessfuly!");
}
@SuppressWarnings("rawtypes")
public boolean hasEventTable() {
// NOTE (Tan Bingjian)
// the values of table_name must be given in capital
List<Map> result = Base.findAll(getSelectTriggerEventTableSql());
return !result.isEmpty();
}
public void createEventTable() {
if (!hasEventTable()) {
logger.debug("TRIGGER_EVENTS is not exist! It will be created .");
Base.exec(getCreateEventTableSql());
logger.debug("TRIGGER_EVENTS create successfuly!");
}
logger.debug("TRIGGER_EVENTS is get ready !");
}
public void dropEventTable() {
if (hasEventTable()) {
Base.exec(getDropEventTableSql());
logger.debug("TRIGGER_EVENTS drop successfuly!");
}
}
@Override
public void create(String name) {
// trigger for insert
Base.exec(sqlForTrigger(name, "insert"));
// trigger for delete
Base.exec(sqlForTrigger(name, "delete"));
// trigger for update
Base.exec(sqlForTrigger(name, "update"));
logger.debug("The triggers on table " + name
+ " create successfuly ! !");
}
@Override
public void remove(String tableName) {
String[] actions = getActionsType();// { "INSERT", "UPDATE", "DELETE" };
for (String i : actions) {
String triggerName = String.format("TR_%s_%s", tableName, i);
logger.debug("look for " + triggerName + " on table :" + tableName);
if (triggerExists(tableName, triggerName)) {
dropTrigger(triggerName);
logger.debug("the trigger has been deleted !");
} else {
logger.debug("the trigger no existe !");
}
}
}
@Override
public void removeAll() {
List<String> tableNames = getAllTables();
for (String name : tableNames) {
remove(name);
}
}
// @Override
public void removeAll(boolean removeEventTable) {
removeAll();
if (removeEventTable && hasEventTable()) {
dropEventTable();
}
}
@SuppressWarnings("rawtypes")
public boolean triggerExists(String tableName, String triggerName) {
List<Map> result = Base.findAll(getSelectTriggersSql(tableName,
triggerName));
return !result.isEmpty();
}
protected void dropTrigger(String triggerName) {
Base.exec(getDropTriggerSql(triggerName));
}
protected String getEventTableName() {
return TRIGGER_EVENT_TABLE_NAME;
}
protected abstract List<String> getAllTables();
protected abstract String getDriverClass();
protected abstract String getUrl();
protected abstract String getSelectTriggerEventTableSql();
protected abstract String sqlForTrigger(String tableName, String opType);
protected abstract String getSelectTriggersSql(String tableName,
String triggerName);
protected abstract String getDropTriggerSql(String triggerName);
protected abstract String getCreateEventTableSql();
protected abstract String getDropEventTableSql();
protected abstract String[] getActionsType();
}
这个只是模板类不做过多介绍，下面是具体的实现类：
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.javalite.activejdbc.Base;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class SyBaseTriggerManager extends AbstractTriggerManager {
private final Logger logger = LoggerFactory
.getLogger(getClass());
private static final String URL_TEMPLATE = "jdbc:sybase:Tds:%s:%s/%s";
private static final String SELECT_TABLES_SQL_TEMPLATE = "select name from sysobjects where type=‘U‘";
private static final String DRIVER_CLASS = "com.sybase.jdbc3.jdbc.SybDriver";
private static final String TRIGGER_EVENT_TABLE_NAME = "TRIGGER_EVENTS";
private static final String SELECT_TRIGGER_EVENT_TABLE_SQL = "select name from sysobjects where name=‘"
+ TRIGGER_EVENT_TABLE_NAME
+ "‘";
private static final String CREATE_TRIGGER_EVENT_TABLE_SQL = "CREATE TABLE "
+ TRIGGER_EVENT_TABLE_NAME
+ "(TRIGGER_EVENTS_ID INT IDENTITY NOT NULL PRIMARY KEY ,"
+ " dbName varchar(30),"
+ " tableName varchar(30),"
+ " pkNames varchar(2000),"
+ " pkValues varchar(2000),"
+ " action varchar(20))";
private static final String SELECT_PK_NAMES_SQL_TEMPLATE = "select columnname from (SELECT object_name(id) tabname, index_col( object_name(id) ,indid,1) columnname FROM sysindexes WHERE status & 2048=2048 "
+ "union "
+ "SELECT object_name(id), index_col( object_name(id) ,indid,2) FROM sysindexes WHERE status & 2048=2048 "
+ "union "
+ "SELECT object_name(id), index_col( object_name(id) ,indid,3) FROM sysindexes WHERE status & 2048=2048 "
+ "union "
+ "SELECT object_name(id), index_col( object_name(id) ,indid,4) FROM sysindexes WHERE status & 2048=2048 "
+ "union "
+ "SELECT object_name(id), index_col( object_name(id) ,indid,5) FROM sysindexes WHERE status & 2048=2048 "
+ "union "
+ "SELECT object_name(id), index_col( object_name(id) ,indid,6) FROM sysindexes WHERE status & 2048=2048 "
+ "union "
+ "SELECT object_name(id), index_col( object_name(id) ,indid,7) FROM sysindexes WHERE status & 2048=2048 "
+ "union "
+ "SELECT object_name(id), index_col( object_name(id) ,indid,8) FROM sysindexes WHERE status & 2048=2048 "
+ "union "
+ "SELECT object_name(id), index_col( object_name(id) ,indid,9) FROM sysindexes WHERE status & 2048=2048 "
+ "union "
+ "SELECT object_name(id), index_col( object_name(id) ,indid,10) FROM sysindexes WHERE status & 2048=2048 "
+ ")pk where columnname is not null and tabname=‘%s‘";
private static final String SELECT_TRIGGERS_SQL_TEMPLATE = "select name from sysobjects where type = ‘TR‘and name=‘%s‘";
private static final String DROP_TRIGGER_SQL_TEMPLATE = "drop trigger %s";
private static final String DROP_TRIGGER_EVENT_TABLE_SQL = "drop table "
+ TRIGGER_EVENT_TABLE_NAME;
private final String url;
private final String host;
private final int port;
private final String db;
private final String user;
private final String password;
public SyBaseTriggerManager(String host, int port, String db, String user,
String password) {
super(user, password);
this.db = db;
this.user = user;
this.port = port;
this.host = host;
this.url = String.format(URL_TEMPLATE, host, port, db);
this.password = password;
}
@SuppressWarnings("rawtypes")
@Override
protected List<String> getAllTables() {
List<Map> result = Base.findAll(SELECT_TABLES_SQL_TEMPLATE);
List<String> names = new ArrayList<String>();
for (Map row : result) {
names.add(row.get("name").toString());
}
return names;
}
protected String getHost() {
return host;
}
protected int getPort() {
return port;
}
protected String getDb() {
return db;
}
protected String getUser() {
return user;
}
protected String getPassword() {
return password;
}
@Override
protected String getDriverClass() {
return DRIVER_CLASS;
}
@Override
protected String getUrl() {
return url;
}
@Override
protected String getSelectTriggerEventTableSql() {
return SELECT_TRIGGER_EVENT_TABLE_SQL;
}
@Override
protected String sqlForTrigger(String tableName, String opType) {
String actionTo;
String[] pkeys = getPks(tableName);
String tigger;
String va = "";
String declare = "";
String values = "";
String pk = "";
if (opType.equals("insert") || opType.equals("update")) {
actionTo = "inserted ";
} else {
actionTo = "deleted ";
}
for (int i = 0; i < pkeys.length; i++) {
pk += pkeys[i] + ",";
va += "@" + pkeys[i] + "+" + "‘,‘" + "+";
declare += "@" + pkeys[i] + " varchar(20)" + ",";
values += "select " + "@" + pkeys[i] + "=convert(char(200),"
+ pkeys[i] + ")" + " from " + actionTo;
}
declare = declare.substring(0, declare.lastIndexOf(","));
va = va.substring(0, va.lastIndexOf("+"));
tigger = "create trigger TR_%s_%s on %s"
+ " for %s as declare %s begin" + " %s insert into %s"
+ "(dbName,tableName,pkNames,pkValues,action)"
+ "values(‘%s‘,‘%s‘,‘%s‘,%s,‘%s‘) end";
return String.format(tigger, tableName, opType, tableName, opType,
declare, values, TRIGGER_EVENT_TABLE_NAME, db, tableName, pk,
va, opType);
}
@Override
protected String getSelectTriggersSql(String tableName, String triggerName) {
return String.format(SELECT_TRIGGERS_SQL_TEMPLATE, triggerName);
}
@Override
protected String getDropTriggerSql(String triggerName) {
return String.format(DROP_TRIGGER_SQL_TEMPLATE, triggerName);
}
@Override
protected String getCreateEventTableSql() {
return CREATE_TRIGGER_EVENT_TABLE_SQL;
}
@Override
protected String getDropEventTableSql() {
return DROP_TRIGGER_EVENT_TABLE_SQL;
}
@SuppressWarnings({ "rawtypes" })
public String[] getPks(String tableName) {
ArrayList<Map> list3 = new ArrayList<Map>();
list3 = (ArrayList<Map>) Base.findAll(String.format(
SELECT_PK_NAMES_SQL_TEMPLATE, tableName));
String[] pkNames = new String[list3.size()];
for (int i = 0; i < list3.size(); i++) {
Map map = list3.get(i);
Set set = map.keySet();
Iterator it = set.iterator();
while (it.hasNext()) {
pkNames[i] = (String) map.get(it.next());
System.out.println(pkNames[i]);
}
}
return pkNames;
}
public void create(String tableName) {
String[] actions = { "insert", "update", "delete" };
for (String i : actions) {
String triggerName = String.format("TR_%s_%s", tableName, i);
if (triggerExists(tableName, triggerName)) {
dropTrigger(triggerName);
}
Base.exec(sqlForTrigger(tableName, i));
}
logger.debug("The triggers on table " + tableName
+ " create successfuly ! !");
}
@Override
protected String[] getActionsType() {
String[] actions = { "insert", "update", "delete" };
return actions;
}
}
关键语句介绍：
private static final String SELECT_PK_NAMES_SQL_TEMPLATE
获取对应表的主键名语句，即对应表的主键名，不过这条语句有个局限性是最多只能获取表中只有10个主键的表，超过十个的话第十一个主键将不再获取。如果大家有更加自由的方法欢迎交流。
protected String sqlForTrigger(String tableName, String opType)
该方法返回创建触发器语句
创建触发器语句：return返回的是完整的语句
tigger = "create trigger TR_%s_%s on %s"
+ " for %s as declare %s begin" + " %s insert into %s"
+ "(dbName,tableName,pkNames,pkValues,action)"
+ "values(‘%s‘,‘%s‘,‘%s‘,%s,‘%s‘) end";
return String.format(tigger, tableName, opType, tableName, opType,
declare, values, TRIGGER_EVENT_TABLE_NAME, db, tableName, pk,
va, opType);
对了，sybase数据库对大小写敏感，还有就是sybase似乎不支持中文创表，和记录中有中午，也许是我还不够了解，懂的朋友欢迎指导
最后，这是第一次写技术博客，就大概贴出了代码，还有很多不足的地方，请大家多多指教，欢迎一起探讨共同进步。
时间： 2024-11-03 05:42:44