oracledialect.java

jsf+spring+ibatis 的一个程序,主要用来介绍JSF程序.

package com.wxd.common.paging;

import org.apache.log4j.Logger;

public class OracleDialect implements Dialect {

	public static Logger log = Logger.getLogger(OracleDialect.class);

	protected static final String SQL_END_DELIMITER = ";";

	public String getLimitString(String sql, boolean hasOffset) {
		sql = sql.trim();
		boolean isForUpdate = false;
		if (sql.toLowerCase().endsWith(" for update")) {
			sql = sql.substring(0, sql.length() - 11);
			isForUpdate = true;
		}
		StringBuffer pagingSelect = new StringBuffer(sql.length() + 100);
		if (hasOffset)
			pagingSelect
					.append("select * from ( select row_.*, rownum rownum_ from ( ");
		else
			pagingSelect.append("select * from ( ");
		pagingSelect.append(sql);
		if (hasOffset)
			pagingSelect.append(" ) row_ where rownum <= ?) where rownum_ > ?");
		else
			pagingSelect.append(" ) where rownum <= ?");
		if (isForUpdate)
			pagingSelect.append(" for update");
		return pagingSelect.toString();
	}

	public String getLimitString(String sql, int pageIndex, int pageSize) {
		sql = sql.trim();
		int m = (pageIndex-1) * pageSize;
		int n = m + pageSize;
		StringBuffer pagingSelect = new StringBuffer(100);
		pagingSelect
				.append("select * from ( select row_.*, rownum rownum_ from ( ");
		pagingSelect.append(sql);
		pagingSelect.append(" ) row_ where rownum <= " + n
				+ ") where rownum_ > " + m);
		return pagingSelect.toString();
	}

	public boolean supportsLimit() {
		return true;
	}

	public String getSequenceNextValString(String sequenceName) {
		return "select " + sequenceName + ".nextval from dual";
	}

	public String getCreateSequenceString(String sequenceName) {
		return "create sequence " + sequenceName;
	}

	public String getDropSequenceString(String sequenceName) {
		return "drop sequence " + sequenceName;
	}

}