Oracle

Multi-Table QueryEquivalent connection (equijoin) Select Ename,empno,sal,emp.deptno from emp,dept where dept.deptno=emp.deptno; non-equivalent connection (non-equijoin) Select Ename, Empno,grade from Emp,salgrade where Sal>losal and SalSelect

Pakeage DAO. Impl;Call function Fun_get ();public string Get (string id,string Name) {Return GetSession (). Createsqlquery ("Select Fun_get (?,?) From dual "). Setparameter (0, Id). Setparameter (1, Name). Uniqueresult (). toString ();}Uniqueresult (

Switch Oracle user su-oracle----------------------------Restart the database sqlplus sys/as sysdbashutdown immediatestartup;-------------- --------------Export a single table exp pls/[email protected] file=/home/oracle/boz.dmp Tables=edu_version_set_

When you do DDL operations on partitions, the partitioning global index is invalidated, and the keyword update global indexes is required.Sql> select * from V$version;BANNER-----------------------------------------------------------------------------

In the practice case when the statement, encountered an example, the result of the answer is not correct, the syntax will not pass, began to think is not a case can only be a fixed value, after all, the example given is a fixed value, after a long

For Oracle, use code FirstThis article is good:Http://www.cnblogs.com/wlflovenet/p/4187455.htmlAdd:The article mentions machine.config need to have:If you only install Oracle managed drivers through NuGet in VS, there is no.At first I do not care,

1. * Number of execution efficiency caused byMinimize the use of SELECT * to query, when you query using *,The database is parsed and the * is converted to all columns.Select COUNT (si.student_id)From Student_info si (student_id as index)AndSelect

Use the cmd Operation command to export, the details are as follows (note: Method two is reprinted online tutorial):The 1:g:\oracle\product\10.1.0\client_1\network\admin directory has a Tnsname.ora file with the following contents:Cmstar

I. Using a FOR loop cursor:1. Define a cursor (a cursor is a small collection)2. Defining cursor Variables3. Using a For loop cursorDeclare --Define cursor c_job cursor c_job is select Empno, ename, Job, Sal from emp where job = ' MANAGER ';

RowNum and rowID are pseudo-columns, but the root of the two is different, rownum is to assign a logical number to each row based on the results of the SQL query, so your SQL will result in a different final rownum, but rowID is physically

A unique constraint is a unique constraint that requires a column type to not allow duplicate values. You can add a unique constraint for a separate column, or you can add a unique constraint (which is a table-level constraint) for multiple columns.

A check constraint is an inspection constraint that, when using a check constraint, checks every data entered, and only records that meet the criteria are saved to the table, guaranteeing the validity and completeness of the data.Check constraints

Sometimes we encounter problems that the database is not able to connect to, and of course there are many reasons for this problem, one of which is because the database service is not started.Here's how to start the Oracle database service:Very

Method OneReturns a null representation string that returns a value greater than or equal to 1 with a non-numeric characterSelect LENGTHB (LTrim (' 1248346 ', ' 0123456789 ')) from dual;OrSelect LENGTHB (RTrim (' 1248346a ', ' 0123456789 ')) from

OracleXE Installation DetailsI. unmount the original databaseThe database uninstallation is not much said. Let's talk about the process: 1. Execute Oracle Uninstall, uninstall Oracle product 2, delete all Oracle related items under regedit 3,

Oracle mobile tableOracle mobile tableWhen creating a table, you can specify a storage space for the table. If not specified, oracle will store the table to the default tablespace. You can move a table from one tablespace to another as needed.

Oracle OBJ4 ORA-8102 fault recovery case Next let's take a look at the oracle OBJ4 ORA-8102 fault recovery case, I hope this article can help you. In the test environment for OBJ $ I _obj4 appears in the ORA-8102 re-and recovery test, think that you

Oracle object typeOracle object typeObject Type In PL/SQL, object-oriented programmers are based on object types. The object type is a user-defined Composite data type. It encapsulates the data structure and processes and functions used to

[Dan JIU Jian] Oracle knowledge point sorting (7) database common objects: Cursor and oraclecursorLink navigation for this series: [Lone sword] Oracle knowledge point sorting (1) Table space and users [Gu JIU Jian] Oracle knowledge point sorting (2)

[Gu JIU Jian] Oracle knowledge point sorting (10) % type and % rowtype and common functions, % type % rowtypeLink navigation for this series: [Lone sword] Oracle knowledge point sorting (1) Table space and users [Gu JIU Jian] Oracle knowledge point