一、多表联合查询 二、子查询 三、动态条件查询 LESSON 4 Displaying Data from Multiple Tables--- 查询s_emp表中最大的工资数,并且显示出这个最
Multitable inserts allow a single INSERT INTO .. SELECT statement to conditionally, or non-conditionally, insert into multiple tables. This statement reduces table scans and PL/SQL code necessary for performing multiple conditional inserts compared to previous versions. It's main use is for the ETL...
SQL> select table_name from user_tables; TABLE_NAME --- DEPT EMP BONUS SALGRADE 类型为number的列宽是用99999或999,99的格式来设置的。 99999表示列宽设为五位数,999,99表示列宽设为6位数,因为逗号也算一位。 SQL> select * from dept; DEPTNO DNAME LOC --- --- --- 10 ACCOUNTING NEW YORK 20 ...
FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA = 'test'; 3. 查询索引占用的空间大小 如果您想单独查询索引占用的空间大小,可以参考以下 SQL: SELECT TABLE_NAME, INDEX_NAME, SEQ_IN_INDEX, COLUMN_NAME, INDEX_TYPE FROM INFORMATION_SCHEMA.STATISTICS WHERE TABLE_SCHEMA = 'test'; 此查询将返回表中所...
SQL> select * from dba_sys_privs where GRANTEE='TEST_PRIVS'; no rows selected 赋予resource角色 SQL> grant resource to TEST_PRIVS; Grant succeeded. 查询resource角色所具有的系统权限 SQL> select * from dba_sys_privs where GRANTEE='RESOURCE'; ...
Your physical data model might stretch across multiple Oracle schemas. Or maybe you just want a single diagram containing tables, views, etc. spanning more than a single user in the database. The process for importing a data dictionary is the same, regardless if you want to ...
本文介绍如何将链接服务器从运行 Microsoft SQL Server 的计算机设置为 Oracle 数据库,并提供在将链接服务器设置为 Oracle 数据库时可能会遇到的常见错误的基本故障排除步骤。
·Exporting and importing partitions in datawarehousing tables ·Publishing structured data on CDs ·Copying multiple read-only versions of atablespace on multiple databases ·Archiving historical data ·Performing tablespace point-in-time-recovery(TSPITR) ...
Pivot SQL tables with CASE or FILTER. Turn rows into columns for the entity-attribute-value model (EAV).
(1) Exporting and importingpartitions in data warehousing tables (2) Publishing structured data onCDs (3) Copying multiple read-onlyversions of a tablespace on multiple databases (4) Archiving historical data (5) Performing tablespacepoint-in-time-recovery (TSPITR) ...