Oracle

问题 I needed to change the SID of an Oracle XE database (not the Service Name) to match a production database. When I tried searching online, most of the pages were describing changing or adding a service name through tnsnames.ora; that's not what I needed to do. 回答1: The asktom article has the answer, but the formatting and verbosity makes it hard to follow, so here's a summary: [XE_HOME] means where Oracle XE is installed. Normally this is C:\oraclexe\app\oracle\product\10.2.0\server . Make

问题 Suppose that we have following tables create table Employee( 2 EMPNO NUMBER(3), 3 ENAME VARCHAR2(15 BYTE), 4 HIREDATE DATE, 5 ORIG_SALARY NUMBER(6), 6 CURR_SALARY NUMBER(6), 7 REGION VARCHAR2(1 BYTE), 8 MANAGER_ID NUMBER(3) 9 ) and create table job ( 2 EMPNO NUMBER(3), 3 jobtitle VARCHAR2(20 BYTE) 4 ) 5 / I am interested in what the below query does SELECT empno, manager_id, ename 2 FROM employee 3 START WITH empno = 1 4 CONNECT BY PRIOR empno = manager_id; As I understood this code selects

问题 Suppose that we have following tables create table Employee( 2 EMPNO NUMBER(3), 3 ENAME VARCHAR2(15 BYTE), 4 HIREDATE DATE, 5 ORIG_SALARY NUMBER(6), 6 CURR_SALARY NUMBER(6), 7 REGION VARCHAR2(1 BYTE), 8 MANAGER_ID NUMBER(3) 9 ) and create table job ( 2 EMPNO NUMBER(3), 3 jobtitle VARCHAR2(20 BYTE) 4 ) 5 / I am interested in what the below query does SELECT empno, manager_id, ename 2 FROM employee 3 START WITH empno = 1 4 CONNECT BY PRIOR empno = manager_id; As I understood this code selects

问题 Suppose that we have following tables create table Employee( 2 EMPNO NUMBER(3), 3 ENAME VARCHAR2(15 BYTE), 4 HIREDATE DATE, 5 ORIG_SALARY NUMBER(6), 6 CURR_SALARY NUMBER(6), 7 REGION VARCHAR2(1 BYTE), 8 MANAGER_ID NUMBER(3) 9 ) and create table job ( 2 EMPNO NUMBER(3), 3 jobtitle VARCHAR2(20 BYTE) 4 ) 5 / I am interested in what the below query does SELECT empno, manager_id, ename 2 FROM employee 3 START WITH empno = 1 4 CONNECT BY PRIOR empno = manager_id; As I understood this code selects

问题 Suppose that we have following tables create table Employee( 2 EMPNO NUMBER(3), 3 ENAME VARCHAR2(15 BYTE), 4 HIREDATE DATE, 5 ORIG_SALARY NUMBER(6), 6 CURR_SALARY NUMBER(6), 7 REGION VARCHAR2(1 BYTE), 8 MANAGER_ID NUMBER(3) 9 ) and create table job ( 2 EMPNO NUMBER(3), 3 jobtitle VARCHAR2(20 BYTE) 4 ) 5 / I am interested in what the below query does SELECT empno, manager_id, ename 2 FROM employee 3 START WITH empno = 1 4 CONNECT BY PRIOR empno = manager_id; As I understood this code selects

问题 In an Oracle PL/SQL block, why is dynamic sql allowed begin execute immediate 'drop table table_name'; end; but static is not? begin drop table table_name; end; I hope the answer is more insightful than "because that's how the language works". 回答1: The answer is PL/SQL does not support dynamic polymorphism. it only supports static polymorphism because All PL/SQL generats a "DIANA" -> Descriptive Intermediate Attributed Notation for Ada , a tree-structured intermediate language. DIANA is used

问题 Can someone please tell me: how long will data be there in a Global Temporary table? 回答1: They can be SESSION based (data survives a commit but not a disconnect/reconnect). They can also be TRANSACTION based (data disappears after a commit). This creates a transaction based temp table: create global temporary table temp_table_transaction on commit delete rows ... This creates a session based temp table: create global temporary table temp_table_transaction on commit preserve rows ... 回答2: When

问题 Can someone please tell me: how long will data be there in a Global Temporary table? 回答1: They can be SESSION based (data survives a commit but not a disconnect/reconnect). They can also be TRANSACTION based (data disappears after a commit). This creates a transaction based temp table: create global temporary table temp_table_transaction on commit delete rows ... This creates a session based temp table: create global temporary table temp_table_transaction on commit preserve rows ... 回答2: When

问题 I have read several posts on this online, but none of them have resolved my issue. Most of the questions posted online point me towards checking Dbnull values from the database and I am doing that in the code. Here's the code where the exception is thrown: int rowNum = Convert.ToInt32(dataTable.Rows[r][dataTable.Columns.Count - 2]); Here's the code where I am checking for the dbnull values: for (int r = 0; r < dataTable.Rows.Count - 1; r++) //rows { for (int c = 1; c < dataTable.Columns.Count

问题 Is there any way to create oracle scheduler job that works (begin and end of some procedure) every day, five times a day at 8,10,12,14,16? 回答1: Use this interval definition: 'freq=daily;byhour=8,10,12,14,16;byminute=0' So the full code to create the job would be something like: DBMS_SCHEDULER.create_job( job_name => 'the_job', job_type => 'STORED_PROCEDURE', job_action => 'YOUR_PROCEDURE', repeat_interval => 'freq=daily;byhour=8,10,12,14,16;byminute=0', enabled => TRUE); 来源： https:/