mongodb 搜索语句 与 SQL 语句对比
所有操作都是在mongo 客户端实施：

先向数据库中插入一些数据作为样本：
//文件集为test.test

>show dbslocal   (empty)> use test> db.test.insert({"TimeStamp":500001,"ProcessID":1001,"ThreadID":2001,"CPU":12})> db.test.insert({"TimeStamp":500002,"ProcessID":1001,"ThreadID":2001,"CPU":13,"Descreption":"Hello World 2"})> db.test.insert({"TimeStamp":500003,"ProcessID":1001,"ThreadID":2001,"CPU":13,"Descreption":"Hello World 3"})> db.test.insert({"TimeStamp":500004,"ProcessID":1001,"ThreadID":2001,"CPU":13,"Descreption":"Hello World 4"})> db.test.insert({"TimeStamp":500005,"ProcessID":1001,"ThreadID":2001,"CPU":13,"Descreption":"Hello World 5"})> db.test.insert({"TimeStamp":500006,"ProcessID":1001,"ThreadID":2001,"CPU":13,"Descreption":"Hello World 6"})>db.test.insert({"TimeStamp":500007,"ProcessID":1001,"ThreadID":2001,"CPU":13,"Descreption":"Hello World 7"})> db.test.insert({"TimeStamp":500008,"ProcessID":1001,"ThreadID":2001,"CPU":13,"Descreption":"Hello World 8"})> db.test.insert({"TimeStamp":500009,"ProcessID":1001,"ThreadID":2001,"CPU":13,"Descreption":"Hello World 9"})> db.test.insert({"TimeStamp":500010,"ProcessID":1001,"ThreadID":2001,"CPU":13,"Descreption":"Hello World 10"})

//select TimeStamp from test where Descreption like '%1%'
按找指定字段按条件，并可指定排序 1:返回字段，0不返回字段

//列显示用1，不显示用0> db.test.find({"Descreption":{"$regex":".*1.*"}},{"TimeStamp":1}){ "_id" : ObjectId("4f66a9a2ad4aa301dccb47ab"), "TimeStamp" : 500001 }{ "_id" : ObjectId("4f66aa11ad4aa301dccb47b4"), "TimeStamp" : 500010 }

> db.test.find({"Descreption":{"$regex":".*1.*"}},{"TimeStamp":0}){ "_id" : ObjectId("4f66a9a2ad4aa301dccb47ab"), "ProcessID" : 1001, "ThreadID" : 2001, "CPU" : 12, "Descreption" : "Hello World 1" }{ "_id" : ObjectId("4f66aa11ad4aa301dccb47b4"), "ProcessID" : 1001, "ThreadID" : 2001, "CPU" : 13, "Descreption" : "Hello World 10" }>

更多内容请查看下面的链接：
http://www.mongodb.org/display/DOCS/Advanced+Queries
http://www.mongodb.org/display/DOCS/Querying#Querying-QueryExpressionObjects
http://www.cnblogs.com/jiangzhichao/archive/2011/10/24/2223186.html