020be3558983ede78cb2a14da0d336ef9b2deec5.svn-base
2.15 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
/**
* Copyright © 2015-2018 ODM All rights reserved.
*/
package com.thinkgem.jeesite.common.persistence.dialect.db;
import com.thinkgem.jeesite.common.persistence.dialect.Dialect;
/**
* Oracle的方言实现
* @author poplar.yfyang
* @version 1.0 2010-10-10 下午12:31
* @since JDK 1.5
*/
public class OracleDialect implements Dialect {
@Override
public boolean supportsLimit() {
return true;
}
@Override
public String getLimitString(String sql, int offset, int limit) {
return getLimitString(sql, offset, Integer.toString(offset), Integer.toString(limit));
}
/**
* 将sql变成分页sql语句,提供将offset及limit使用占位符号(placeholder)替换.
* <pre>
* 如mysql
* dialect.getLimitString("select * from user", 12, ":offset",0,":limit") 将返回
* select * from user limit :offset,:limit
* </pre>
*
* @param sql 实际SQL语句
* @param offset 分页开始纪录条数
* @param offsetPlaceholder 分页开始纪录条数－占位符号
* @param limitPlaceholder 分页纪录条数占位符号
* @return 包含占位符的分页sql
*/
public String getLimitString(String sql, int offset, String offsetPlaceholder, String limitPlaceholder) {
sql = sql.trim();
boolean isForUpdate = false;
if (sql.toLowerCase().endsWith(" for update")) {
sql = sql.substring(0, sql.length() - 11);
isForUpdate = true;
}
StringBuilder pagingSelect = new StringBuilder(sql.length() + 100);
if (offset > 0) {
pagingSelect.append("select * from ( select row_.*, rownum rownum_ from ( ");
} else {
pagingSelect.append("select * from ( ");
}
pagingSelect.append(sql);
if (offset > 0) {
String endString = offsetPlaceholder + "+" + limitPlaceholder;
pagingSelect.append(" ) row_ where rownum <= "+endString+") where rownum_ > ").append(offsetPlaceholder);
} else {
pagingSelect.append(" ) where rownum <= "+limitPlaceholder);
}
if (isForUpdate) {
pagingSelect.append(" for update");
}
return pagingSelect.toString();
}
}