The supplement of sorting "median order cardinal method to achieve tree structure"
Due to a momentary negligence, the method "for the base digit segment of type int, there can only be 31 replies to the original post, the base number of the numeric type, and no more than 120 replies to the original paste (in fact, for the Int field, the original post reply to the 32nd tree structure shows the beginning of the disorder, For a numeric-type base digit se
operation. 2) backing up the Mysqla database mysqldump--uroot-p--single-transaction--opt--events--triggers--routine
s--flush-logs--master-data=2--databases db1 DB2 >db.sql--flush-logs: Option to generate a new binary log file (scrolls the binary file so that it starts in a full position) --mater-data : the option value equals 2, and the change master statement in the backed-up SQL file is commented. --single-transaction:innodb table when backing up, the option--single-transaction is usually
SELECT * FROM (select RowNum rn,e2.* from (select e1.* from EMP E1) E2 where rownumSELECT * FROM (select RowNum en,e.* from emp e)Select E.deptno,e.ename,d.dname,e.mgr,s.gradeFrom (select AVG (SAL) ea from emp) e1,emp E,salgrade s,dept Dwhere E.deptno=e.mgrand D.deptno=e.deptnoand e.sal>e1.ea;--Copy table dataCREATE TABLE Emps as SELECT * from EMP;--View Table contentsDESC EMP;Select table_name from all_tables where Owner=upper (' Legend ');--Copy table structureCREATE TABLE Empnew as SELECT * f
Tags: style yum str enter DIV inux BSP Body dbaThe linuxoracle of Evil and supplementary articlesLinux simultaneously Open two terminals:ctrl+shift+tLinux configuration Yum file:/etc/yum.repos.d/xx.repoLinux switch users:su-usernameOracle Connectivity:sqlplus/as sysdba;conn/as sysdba;Grid to view the status of the database, the target of the database ORCL is ofline How to start for online:Srvctl Enable database-d ORCLSrvctl Start database-d ORCL"Linuxoracle" linuxoracle the Evil
mytable from Database mydb to the E:\MySQL\mytable.sql file.
c:\> mysqldump-h localhost-u root-p mydb mytable>e:\mysql\mytable.sql
Example 3: Export the structure of the database mydb to a e:\MySQL\mydb_stru.sql file.
c:\> mysqldump-h localhost-u root-p mydb--add-drop-table >e:\mysql\mydb_stru.sql
Note :-h localhost can be omitted, it is generally used on the virtual host.3) Export data structure onlyformat : mysqldump-u [Database user name]-p-t [the name of the data
--range-> select * from TB1 where name Gt 'Alex'Special: If the primary key or index is an integer type, then the index select * from TB1 where nid > 123 select * from TB1 where num > 123- Order BY Select e-mail from tb1 order by name Desc; When sorting by index, the selected mappings are not indexed if they are not indexes: if the primary key is sorted, then the index: SELECT * from Tb1 ORDER by nid desc; -Combined index leftmost prefix if the combined index is: (name,email)
Multi-table query mysql support is SQL99 standard connection query, does not support Oracle Company's external connection query, but supports Oracle equivalent query, not equivalent query, self-connection query, subquery (as long as it is not an outer join ( + ) are supported) Oracle also supports SQL99 standard connection queries Internal Connection--equivalent QuerySelectE.empno,e.ename,e.sal,d.dname fromEMP Einner Join dept Don E.deptno=D.deptno;--To put it simply: replace the comma in the
Back to Catalogmultipleactiveresultsets can make the database connection reusable, but when you're on the Moebius cluster tool, this option doesn't turn on (false by default), and when you use an ORM tool like EF, This option will be added by default, it is to improve the performance of the program, the advantage is that the database connection resources are exhausted, the use of the method is simple, only need to add it to the data connection string.For example: server= (local); Integrated Secu
Label:Previously there was a replica set to build mongodb3.0, but the admin database that was used directly was the root of the user. Links: http://blog.csdn.net/tuzongxun/article/details/51723259Recently you want to move data to a non-admin database, and then re-create the user in the non-admin library, the process is roughly the same as before, but there are some problems when creating the user, mainly on the user roles and permissions. I built the process to refer to the following user rights
(sysdate, ' D ') from dual; 5 March 14, 2002 for Monday DY Week the first day abbreviation Select to_char (sysdate, ' DY ') from dual; SUN March 24, 2002 for Sunday HH or HH12 12 input hours Select to_char (sysdate, ' HH ') from dual; 02 Midnight 2 O'Clock 8 02 HH24 24-hour Select to_char (sysdate, ' HH24 ') from dual; 14 2:08 P.M. to 14 MI minutes (0~59) Select to_char (sysdate, ' MI ') from dual; 17 4:17 P.M. SS seconds (0~59) Select to_char (sysdate, ' SS ') from dual; 22 11 points 3 minutes
/archive/2010/12/20/imcp.htmlSummarizeA nosql-supplemented architecture is centered on the idea of MySQL architecture, and it's just that the previous architectures have assisted in adding nosql to improve performance and scalability. This architecture is relatively easy to implement, but it can achieve good results. Hopefully this article will help you if you're trying to introduce NoSQL into your project, or if your MySQL-based system is currently having a bottleneck associated with it.
Label:These two days did the import and export table data for Oracle. 1.oracle provides three ways to import and export files, (1) Oracle Export/import (2) SLQ export/import (3) PL/SQL Export Import The second method is suitable for import and export of single or several tables, and the amount of data exported is smaller. If it is a large amount of data or a table is more, it is best to use the first method. The third method must have PL/SQL. 2. Precautions (1) When exporting a table, the second
spent the 10 Many minutes, probably pc Recommended Links:1, the Android SDK manager update download slow solution:http://my.oschina.net/765155496/blog/2992722, the establishment of virtual machines: Baidu (Geek College Android introductory video) 3 Tip:emulator:ERROR:x86 emulation currently requires hardware acceleration! Please ensure the Intel HAXM is properly installed and usable. : Installation HAXM: http://blog.csdn.net/rznice/article/details/402102134 6 Build your first debug program an
", "Age": 20}6, the universal parameters (A * must be placed in front)def f3 (*args,**kwargs):Format ()S1 = "I am {0}, age {1}". Format ("LZ", "a") s2 = "I am {0}, age {1}". Format (*["LZ", +]) s3 = "I am {name},age {age}". Format (Nam E=LZ.AGE=20) S4 = "I am {name},age}". Format (**{"name": "LZ", "Age": +}) "I am lz,age 20"7. The function parameter is passed as a referenceGlobal variables, all scopes are readableThe global variable is "re-assigned" and requiresSpecial: List, dictionary, modifia
}, age {1}, really {0}". Format ("Wenchong", 8) S4="I am {0}, age {1}, really {0}". Format (*["Wenchong", 8]) S5="I am {name}, age {age}, really {name}". Format (name="Wenchong", age=8) S6="I am {name}, age {age}, really {name}". Format (**{"name":"Wenchong"," Age": 18}) S7="I am {0[0]}, age {0[1]}, really {0[2]}". format ([1, 2, 3], [11, 22, 33]) S8="I am {: s}, age {:d}, Money {: F}". Format ("Wenchong", 8, 88888.1) S9="I am {: s}, age {:d}". Format (*["Wenchong", 8]) S10="I am {name:s}, age {
3. Supplement of strings, lists, tuples, dictionaries, and collections, and string dictionariesRelated:
String
List
Dictionary
Set
Additional:
Many python compilers provide code complementing functions and prompt functions when entering parameters.
String
1. Common functions:
The string is an immutable object, and the string method does not change the data of the original string.
S = "hEllo world! \ T "print (" s.
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