本地建一张表persons,使用脚本插入了1000万条数据 下面比较几种查询方法的耗时(查询9000000到9000005这中间5条数据) 查询结果: 1: SELECT * FROM test.persons limit 9000000,5; 2: SELECT * FROM test.persons where Id_P between 9000000 and 9000005; 可见几乎不消耗时间 3: SELECT * FROM test.persons where Id_P in(900…
1.前言 在研究ArcGIS API for JavaScript时会遇到这样的问题,比如我们在做缓冲区分析时,用分析的范围作为空间查询query的参数,在执行结果中总是会看到“esri.config.defaults.io.proxyUrl 尚未设置”错误,但是我们手动绘制一个简单多边形作为输入参数则不会出现上述错误. 问题原因: 一般使用框选的时候对query.geometry,我们一般会赋予一个Extent变量,但是当我们需要用一个比如圆,或者点很多的不规则多边形的Polygon去查询时,…
主要知识点 match all match multi match range query term query terms query exist query 1.match all 查询所有 GET /_search { "query": { "match_all": {} } } 示例: GET /company/employee/_search { "query": { "match_all": {}…
注解 @Query 允许在方法上使用 JPQL. 列如: @Query("select u from User u where u.name=?1 and u.department_id=?2") public User findUser(String name,Integer departmentId); 如果是使用SQL,而不是JPSQL,可以使用 @Query 的 nativeQuery属性,设置为true:例如 @Query(value="select * from…
问题SQL: select p.person_id as personId, p.person_name as personName, p.native_place as nativePlace, ci.company_name as companyName, pp.seal_number as sealNumber, GROUP_CONCAT(pp.major) as major, pp.register_name as registerName from qyt_person p left…
When you query a SharePoint calendar your results will contain: All non-recurring events The first event of a recurring event series And won’t contain: All remaining events in recurring event series’ Here is the CAML you need to execute to retrieve a…
with QS as( select cp.objtype as object_type, /*类型*/ db_name(st.dbid) as [database], /*数据库*/ object_schema_name(st.objectid,st.dbid) as [schema], /*架构*/ object_name(st.objectid,st.dbid) as [object], /*对象名*/ ),qs.creation_time,) as plan_creation, /*计划…
rails generate model photo title:string album:references 这会产生一个album_id列,当建立belongs_to关联时,需要用到. references算时一种结构,会产生integer. For integer, string, text and binary fields, an integer in curly braces will be set as the limit: `rails generate model user…
qs.total_worker_time/qs.execution_count as [Avg CPU Time], , ( ) as query_text, qt.dbid, dbname=db_name(qt.dbid), qt.objectid FROM sys.dm_exec_query_stats qs cross apply sys.dm_exec_sql_text(qs.sql_handle) as qt ORDER BY [Avg CPU Time] DESC…
