SELECTUPPER('This is a string')FROMwhat_table;Code language:SQL (Structured Query Language)(sql) In this case, you might think about creating a table and use it in theFROMclause for just using theUPPER()function. Fortunately, Oracle provides you with theDUALtable which is a special table ...
things basedonthat.8) dual = magic. dualisa one row table however having morethen1orlessthenoneisdangerous. You are updating the data dictionary. You should naturally expect very bad thingstohappen. 简单总结,意思如下: DUAL is a convienence table The column, its name, its datatype and even...
This is because the FROM is required. Now, this is only Oracle-specific. If you’ve used SQL Server or MySQL, you don’t need to specify a DUAL table. What Columns Can I Select? I mentioned earlier that the DUAL table is a dummy table used for functions and calculations in your qu...
dual是一个表,有一个名为DUMMY,类型为VARCHAR2(1)。DUMMY这个词在英文中的含义为“something designed to resemble and serve as a substitute for the real...
The most common strong authentication policy is dual-factor authentication. When logging in to the system, a user needs to provide not only the user name and password, but also the items bound to the user name and password (for example, USB keys are widely used in online banking), or ...
The most common strong authentication policy is dual-factor authentication. When logging in to the system, a user needs to provide not only the user name and password, but also the items bound to the user name and password (for example, USB keys are widely used in online banking), or ...
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In some cases, such as when national security is at stake, the customer may choose a fully dedicated facility. 3. Operations and support An organization should control which administrative and technical staff, from both the cloud provider and its partners, may have access to their systems, as ...
Re: why does "select 1 from dual" work - what is the "1"? Hi,this is all explained in the documentation :"DUAL is a table automatically created by Oracle Database along with the data dictionary. DUAL is in the schema of the user SYS but is accessible by the n...
Here is the creation DDL for the well-known table SCOTT.EMP as generated in Oracle Database 11g release 2. SQL> select dbms_metadata.get_ddl('TABLE','EMP','SCOTT') from dual; CREATE TABLE "SCOTT"."EMP" ( "EMPNO" NUMBER(4,0) NOT NULL ENABLE, "ENAME" VARCHAR2(10), ...