select 'drop table '||table_name||';' as sqlscript from user_tables;
SQLSCRIPT
--------------------------------------------
drop table LO_CASEINFO;
drop table LO_HARMONIZECASE;
drop table LO_LAWCHECK;
drop table LO_LEGISLATIONITEM;
drop table LO_TRAINBATCH;
drop table OA_IMPRESS;
drop table OA_SYSGROUP;
java.lang.InternalError: Can´t connect to X11 window server using ´:0.0´ as the value of the DISPLAY variable.
at sun.awt.X11GraphicsEnvironment.initDisplay()V(X11GraphicsEnvironment.java:???)
at sun.awt.X11GraphicsEnvironment.<clinit>()V(X11GraphicsEnvironment.java:134)
at jrockit.vm.Classes.forName0(Ljava.lang.String;ZI)I(Unknown Source)
at jrockit.vm.Classes.forName(Ljava.lang.String;ZLjava.lang.ClassLoader;)Ljava.lang.Class;(Unknown Source)
at java.lang.Class.forName(Ljava.lang.String;I)Ljava.lang.Class;(Unknown Source)
at java.awt.GraphicsEnvironment.getLocalGraphicsEnvironment()Ljava.awt.GraphicsEnvironment;(GraphicsEnvironment.java:62)
at net.sf.jasperreports.engine.util.JRGraphEnvInitializer.initializeGraphEnv()V(JRGraphEnvInitializer.java:58)
at net.sf.jasperreports.engine.fill.JRBaseFiller.<init>(Lnet.sf.jasperreports.engine.JasperReport;Lnet.sf.jasperreports.engine.fill.JREvaluator;Lnet.sf.jasperreports.engine.fill.JRBaseFiller;)V(JRBaseFiller.java:307)
at net.sf.jasperreports.engine.fill.JRVerticalFiller.<init>(Lnet.sf.jasperreports.engine.JasperReport;Lnet.sf.jasperreports.engine.fill.JREvaluator;Lnet.sf.jasperreports.engine.fill.JRBaseFiller;)V(JRVerticalFiller.java:92)
at net.sf.jasperreports.engine.fill.JRVerticalFiller.<init>(Lnet.sf.jasperreports.engine.JasperReport;)V(JRVerticalFiller.java:74)
at net.sf.jasperreports.engine.fill.JRFiller.createFiller(Lnet.sf.jasperreports.engine.JasperReport;)Lnet.sf.jasperreports.engine.fill.JRBaseFiller;(JRFiller.java:147)
at net.sf.jasperreports.engine.fill.JRFiller.fillReport(Lnet.sf.jasperreports.engine.JasperReport;Ljava.util.Map;Lnet.sf.jasperreports.engine.JRDataSource;)Lnet.sf.jasperreports.engine.JasperPrint;(JRFiller.java:83)
at net.sf.jasperreports.engine.JasperFillManager.fillReport(Lnet.sf.jasperreports.engine.JasperReport;Ljava.util.Map;Lnet.sf.jasperreports.engine.JRDataSource;)Lnet.sf.jasperreports.engine.JasperPrint;(JasperFillManager.java:601)
...
如果要使用 >,>=,=,Between...and 操作符,可以使用子查询把rownum转为实际列: select namef from (select rownum r,namef from tablename)t where r > 10; select namef from (select rownum r,namef from tablename)t where r between 10 and 20;
Oracle中的rownum的是在取数据的时候产生的序号,所以想对指定排序的数据去指定的rowmun行数据就必须注意了。 SQL> select rownum ,id,name from student order by name; ROWNUM ID NAME ---------- ------ --------------------------------------------------- 3 200003 李三 2 200002 王二 1 200001 张一 4 200004 赵四 可以看出,rownum并不是按照name列来生成的序号。系统是按照记录插入时的顺序给记录排的号,rowid也是顺序分配的。为了解决这个问题,必须使用子查询 SQL> select rownum,id,name from (select * from student order by name); ROWNUM ID NAME ---------- ------ --------------------------------------------------- 1 200003 李三 2 200002 王二 3 200001 张一 4 200004 赵四 这样就成了按name排序,并且用rownum标出正确序号。