我正在读一本提到
的书本地临时表在创建它们的级别中可见，跨批次以及在调用堆栈的所有内层中。因此，如果在代码中的特定级别创建临时表，然后执行动态批处理或存储过程，则内部批处理可以访问临时表。
和
即使在同一级别的批次中，表变量也不可见
从其他来源，据我所知，本地临时表对于创建它的会话是可见的，并在会话关闭时被销毁。
那么什么是“级别”和“调用堆栈的内部级别”呢？
答案 0 :(得分：2)
Picture a stored procedure called com.$company.DBDataSetException: java.sql.SQLException: Connection refused: connect
at com.$company.DBDatabase.setConnection(DBDatabase.java:43)
at em.cabbench.$client.ERPInterface$client.connectToConnx(ERPInterface$client.java:137)
at em.cabbench.$client.ERPInterface$client.getERPRawMaterialPrice(ERPInterface$client.java:167)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at em.cabbench.RequestTypes.call(RequestTypes.java:1120)
at em.cabbench.CabBenchSrv.processRequest(CabBenchSrv.java:988)
at em.cabbench.CabBenchSrv.doGet(CabBenchSrv.java:828)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:723)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:861)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:620)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Unknown Source)
Caused by: java.sql.SQLException: Connection refused: connect
at com.Connx.jdbc.TCJdbc.TCJdbcDriver.connect(TCJdbcDriver.java:251)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at com.$company.DBDatabase.setConnection(DBDatabase.java:40)
... 23 more
Couldn't connect to CONNX
java.lang.NullPointerException
at com.$company.DBDatabase.closeConnection(DBDatabase.java:66)
at em.cabbench.$client.ERPInterface$client.getERPRawMaterialPrice(ERPInterface$client.java:171)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at em.cabbench.RequestTypes.call(RequestTypes.java:1120)
at em.cabbench.CabBenchSrv.processRequest(CabBenchSrv.java:988)
at em.cabbench.CabBenchSrv.doGet(CabBenchSrv.java:828)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:723)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:861)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:620)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Unknown Source)
than, in turn, calls two stored procedures, server specs:
PHP 5.2.4 or greater
MySQL 5.0 or greater
PHP cURL extension
PHP Zlib extension
Unix-like OS (Windows is not supported)
PHP 5.3, 5.4, 5.5 yes
IonCube Loader 4.6.1 or above yes
Mysql 5.0 or above and its support in PHP yes
FFmpeg 1.0 or above with libx264, libavfilter and AAC codec (libfaac, libfdk_aac or native ffmpeg aac codec) yes
cURL and its support in PHP yes
Apache + mod_rewrite + (MultiViews option disabled) yes, not sure about multi views, please ask how this is done.
Zlib library yes
XML extension yes
GD2 with true type font (required!) yes
Ability to exec PHP from CLI using exec() command yes
PHP register_globals off yes
PHP magic_quotes_gpc off yes
PHP safe_mode off yes
PHP file_uploads on yes
PHP allow_url_fopen on yes
and then A1.
Each of these stored procedures creates a temporary table with the same name, prefixed (of course) by B (so, C creates #) as their first action, before running any further code.
You execute the following code in query analyser:
ACode in #A can work with tables CREATE TABLE #F (ID INT NOT NULL)
EXEC A
GO
EXEC A
and A.
Code in #F can work with tables #A, B and #F
Code in #A can work with tables #B, C and #F
Despite #A and #C being at the same "level" (they were both called from B), C cannot access the temp table that A created (it was destroyed when C exited).
1
B