"annual Salary"From EMP ORDER by 3 DESC;SELECT ename,job,sal from emp ORDER by Job,sal DESC;SELECT ename,job,sal from emp ORDER by Empno;Modify Default display widthSET line[size] {80|n}SET Line 100L display the SQL statement in the buffer you just enteredN Text modified section of error'/' (run) commandSAVEGET@ or Start command when the specified script file contents are loaded into the SQL buffer to runS
,guid,ip,date)values(';
set@value1=eid;
set@value2=guid;
set@value3=ip;
set@value4='now())';
set@sql_text:=concat(@temp1,@table,@temp2,@value1,',',@value2,',',@value3,',',@value4);
preparestmtfrom@sql_text;
executestmt;
end;
In doing so, it will certainly have an impact on the performance, and it is only temporary ,,,
Appendix:
MYSQL stored procedures use dynamic SQL to create mul
For some current releases, three dynamic performance views are available for DBAs (Database Administrator, Database Administrator) and developers, namely V $ SQL, V $ SQLAREA, and V $ SQLTEXT.These views can be used to collect statistics about SQL command execution. In Oracle 10g and Release 2, the fourth
execution plan is calculated with accurate data.
The second example shows a more accurate execution plan than dynamic sampling after a table analysis
Dynamic sampling: As the name implies is the Oracle Automatic for you preliminary data analysis, because it is random on the table to take some data, so it is not guaranteed that the implementation plan is very a
Today, I am working on an OA report. I use a stored procedure to calculate some data. When doing a for xxx in xxxx loop end loop; loop, I never knew it was Mao. I can't catch the no_data_found exception in for any more. Once this no_data_found Oracle occurs, it automatically jumps out of the for loop, but I don't know what went wrong, that was depressing for an hour. Shit. Later I remembered that pl/SQL too
Today, I am working on an OA report. I use a stored procedure to calculate some data. When doing a for XXX in xxxx loop end loop; loop,
I never knew it was Mao. I cannot catch the no_data_found exception in for any more. Once this no_data_found occurs
Oracle will automatically Jump Out Of The for loop, but I don't know where the error occurred. It was a depressing hour. Shit.
Later I remembered that PL/SQL
In fact, I think this blog written in Web-based application development is the best, because currently we rarely implement sorting and filtering on the client, and many of the development uses a lightweight two-tier model, so the lack of specialized processing data buffering and filtering business, some people will say, Can we create stored procedures or nested complex control flow blocks? But I want to say that these solutions can only solve part of the problem, but they bring a lot more proble
T-SQL is an enhanced SQL language provided by SQLServer based on the SQL language. The T-SQL provides all the features of ANSISQL and adds more features such as extended functions, system pre-storage, and program design structures. The following describes
3. the T-SQL of
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MyBatis's Dynamic SQL explanationBlog Category:
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MyBatis Dynamic SqldynamicforeachThe Basics section can look at one of my other blogs: http://ha
Tags: admin logs pass description China SSM images identity withWindows Azure Platform Family of articles Catalog When we use relational data, we sometimes want to: -Admin admin, can view all the data -Regular users, some sensitive fields, such as credit cards, e-mails and other fields are masked In this case, you can use Dynamic Data masking to mask some fields of the data table. For example, we have the user's credit card information, email addr
Oracle learning notes 3 SQL commands, oracle learning notes SQLSQL introduction SQL supports the following types of commands: 1. data Definition Language (DDL) 2. data manipulation language (DML) 3. transaction Control Language (TCL) 4. the Data Control Language (DCL) is a detailed note of the four
Oracle tuning uses related SQL, oracle tuning related SQL
Select * from v $ session where username is not null;Select username, count (username) from v $ session where username is not null group by username;Select count (*) from v $ process;Select value from v $ parameter where name = 'processs ';Select count (*) from
Manage common Oracle data dictionaries and dynamic performance views 1.v$ version query database version information
[sql] select * from v$version; [html] BANNER -------------------------------------------------------------------------------- Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Producti
.
V $ SQL: executed SQL statement.
V $ lock: What kind of locks are occupied by those sessions, what kind of locks are applied for, and whether the session is blocked by other sessions.
Which objects are locked by V $ locked_object.
V $ session_wait: Select * from V $ session_wait where wait_class! = 'Idle': Check the currently waiting session, such as the blocked session.
V $ session_wait_history: the hist
Preface: In the process of Oracle operations, often use some dynamic views beginning with v$, such as v$session, once saw someone with v_$session, think someone else wrote wrong, didn't think Desc v_$session can see and v$ Session of the structure, and then found in the beginning of the gv$ view and so on. The opportunity to mount Oracle on a Linux system finally
: Close REF CURSOR name; Sql> declare 2 type emp_cursor is REF CURSOR; 3 my_cursor emp_cursor; 4 v_ename emp.ename%type; 5 v_ Sal Emp.sal%type; 6 V_deptno Dept.deptno%type: = p_deptno; 7 V_dname Dept.dname%type; 8 begin 9 Select Dname to V_dname from dept where deptno = V_deptno; Dbms_output.put_line (' Department: ' || V_dname); One open my_cursor for the ename, Sal from emp where deptno = V_deptno; Loop Fetch my_cursor Exit when My_c
Use of dbms_ SQL in oracle, oracledbms_ SQL
1. Run the query using dbms_ SQL
Use dbms_ SQL to execute the select statement in the order of open cursor --> parse --> define column --> execute --> fetch rows --> close cursor;
1. Create a team table structure, as shown in:
Pro
First look at when to use dynamic performance view:
(1) Nomount
When you start the routine, Oracle opens the parameter file, assigns the SGA, and starts the background process. Therefore, when the routine is in the Nomount state, only access to the dynamic performance view of the information obtained from the SGA is accessible.
(2) MOUNT
When installed in a d
Dynamic SQL
Bad:1. dynamic SQL is very dangerous, because dynamic SQL generally constructs your entire SQL statement based on user input, that is, we usually see some parameters involv
=" 148. PNG "alt=" Wkiom1k0ebuh5supaacsebqj1pu635.png "/>Report:1, MyBatis in the two built-in parameters:_parameter: Represents the entire parameterSingle parameter: _parameter is this parameterMultiple parameters: The parameters are encapsulated in a map: The _parameter represents the map._databaseid: If the Databaseidprovider tag is configured, _databaseid is the alias Oracle representing the current database.2. Extract reusable
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