初始化部分
System.out.println("基础初始化部分开始");
Mongo m = new Mongo("localhost", 27017);
// 选择数据库，如果没有这个数据库的话，会自动建立
DB db = m.getDB("ms_basic");
// 建立一个集合，和数据库一样，如果没有，会自动建立
DBCollection coll = db.getCollection("leeCollection");
DBCursor cur = null;
long startTime = 0;
BasicDBObject query = null;
BasicDBObject field = null;
BasicDBObject sort = null;
List<Object> inList = null;
System.out.println("基础初始化部分完毕");
,,,,
public
static
void
showAllDataFromCursor(DBCursor cur) {
while
(cur.hasNext()) {
System.
out
.println(cur.next());
}
}
普通查询
System.out.println("-----------华丽分隔线---------------");
System.
out
.println(
"
SELECT * FROM schedule
WHERE startDate='2010-11-18' and disciplineName='田径'
and phaseName='决赛'"
);
startTime = System.
currentTimeMillis
();
query =
new
BasicDBObject();
query.put(
"startDate"
,
"2010-11-18"
);
query.
put
(
"disciplineName"
,
"田径"
);
query.put(
"phaseName"
,
"决赛"
);
cur = coll.find(query);
System.
out
.println(
"查询获得的长度"
+cur.count());
System.
out
.println(
"查询耗时:"
+(System.
currentTimeMillis
()-startTime)+
"毫秒."
);
showAllDataFromCursor
(cur);
System.
out
.println(
"-----------华丽分隔线---------------"
);
System.
out
.println(
"SELECT * FROM schedule WHERE rsc='ATM033101'"
);
startTime = System.
currentTimeMillis
();
query =
new
BasicDBObject();
query.put(
"rsc"
,
"ATM033101"
);
cur = coll.find(query);
System.
out
.println(
"查询获得的长度"
+cur.count());
System.
out
.println(
"查询耗时:"
+(System.
currentTimeMillis
()-startTime)+
"毫秒."
);
showAllDataFromCursor
(cur);
System.
out
.println(
"-----------华丽分隔线---------------"
);
System
.
out
.println(
"
SELECT * FROM schedule
order by startDate asc,startTime asc limit 2,10"
);
sort =
new
BasicDBObject();
sort.put(
"startDate"
, 1);
sort.put(
"startTime"
, 1);
startTime = System.
currentTimeMillis
();
cur = coll.find().sort(sort).limit(2).skip(10);
System.
out
.println(
"查询获得的长度"
+cur.count());
System.
out
.println(
"查询耗时:"
+(System.
currentTimeMillis
()-startTime)+
"毫秒."
);
showAllDataFromCursor
(cur);
高级查询
http://www.mongodb.org/display/DOCS/Advanced+Queries
Introduction
Retrieving a Subset of Fields
$slice operator
Conditional Operators : <, <=, >, >=
Conditional Operator : $ne
Conditional Operator : $in
Conditional Operator : $nin
Conditional Operator : $mod
Conditional Operator: $all
Conditional Operator : $size
Conditional Operator: $exists
Conditional Operator: $type
$or
Regular Expressions
Value in an Array
Conditional Operator: $elemMatch
Value in an Embedded Object
Meta operator: $not
Javascript Expressions and $where
sort()
limit()
skip()
snapshot()
count()
group()
Special operators
See Also
这里列举部分示例：
?
Regular Expressions
System.
out
.println(
"-----------华丽分隔线---------------"
);
System.
out
.println(
"
SELECT * FROM schedule
WHERE rsc like 'ATM%'and length(rsc)=9"
);
startTime = System.
currentTimeMillis
();
query =
new
BasicDBObject();
query.put(
"rsc"
,Pattern.
compile
(
"ATM[A-Z0-9]{6}"
, Pattern.
CASE_INSENSITIVE
));
cur = coll.find(query);
System.
out
.println(
"查询获得的长度"
+cur.count());
System.
out
.println(
"查询耗时:"
+(System.
currentTimeMillis
()-startTime)+
"毫秒."
);
showAllDataFromCursor
(cur);
这里可以理解为：
rsc like 'ATM%'and length(rsc)=9
?
选择固定字段
System.
out
.println(
"-----------华丽分隔线---------------"
);
System.
out
.println(
"SELECT rsc,startDate,startTime, competitionStatus FROM schedule WHERE competitionStatus
=1
order by startDate asc,startTime asc limit 10"
);
startTime = System.
currentTimeMillis
();
query =
new
BasicDBObject();
query.put(
"competitionStatus"
,
1
);
field =
new
BasicDBObject();
field.put(
"rsc"
,
true
);
field.put(
"startDate"
,
true
);
field.put(
"startTime"
,
true
);
field.put(
"competitionStatus"
,
true
);
cur = coll.find(query,field).sort(sort).limit(10);
System.
out
.println(
"查询获得的长度"
+cur.count());
System.
out
.println(
"查询耗时:"
+(System.
currentTimeMillis
()-startTime)+
"毫秒."
);
showAllDataFromCursor
(cur);
本文转自jooben 51CTO博客，原文链接:http://blog.51cto.com/jooben/350747
