mysql data dictionary

GV _ $, V _ $ view and V $, GV $ Synonym These views are created through catalog. ql. When catalog. SQL is run: Create or replace view v _ $ fixed_table as select * from v $ fixed_table; Create or replace public synonym v $ fixed_table for v _ $ fixed_table; Create or replace view gv _ $ fixed_table as select * from gv $ fixed_table; Create or replace public synonym gv $ fixed_table for gv _ $ fixed_table; We noticed that the first view V _ $ and GV _ $ were created first, and the views

The above is the dictionary data (picture)Find the path to the application package firstNSBundle *bundle = [NSBundle mainbundle];NSString *path = [bundle Bundlepath];And then read out all the files under the path.Nsfilemanager *FM = [Nsfilemanager Defaultmanager];Nsarray *allfile = [FM Contentsofdirectoryatpath:pathError:nil];NSLog (@ "%@", allfile);Find the file with the picture and add the arrayNsmutablea

In Oracle, the source code of an object can be in the user_source data dictionary. Name type nullable default comments---- -------------- -------- ------- Begin ----------------------------------------------------------------------------------------------------------------------------------------------Name varchar2 (30) y name of the objectType varchar2 (12) Y type of the object: "type", "Type body", "proce

How to filter data by criteria in a list Dictionary collection: listGenerate a random list to filter out negative numbers first1, normal for loop iteration judgment2,filter () function judgment, filter (function, list|tuple|string)1 filter (lambda x:x>0, data)3, List push-down4, efficiency comparison: Or the list deduction is slightly higherTwo: Dictionary1, simi

lengthDBMS_METADATA.GET_DDL: Generating DDL information for database objectsDbms_random: Fast generation of random numbersInitialize: Initialize Dbms_random package, must provide random number seedSeed: Reset random number SeedRandom: Production of stochasticDbms_flashback: Activates or disables the flashback feature of the session, which is required for ordinary users to use authorizationEnable_at_time: Activating session Flashback in a time-based mannerEnable_at_system_change_number: Flashbac

Python's MySQLdb module is a python-connected MySQL module, and the default query results are returned as a tuple type, which can only be accessed through 0,1. Index Access dataDefault Connection database: MySQLdb.connect (Host=host, User=user, passwd=passwd, Db=db, Port=port, charset= ' UTF 8 ') Copy Code Print: Copy the code code as follows for the row in Data:print type (row) print row Execution Result: Copy Code The code is as follows: is a tu

Dictionary data table design and table field sorting Method for reading dictionary metadata procedure setdataset (Dataset: tdataset; const table: string ); VaR D: tadoquery; I: integer; Begin If dataset = nil then exit; If not dataset. Active then exit; If table = ''then exit; D: = tadoquery. Create (NiL ); Try With d do Begin Connection: = ufunction. getconnec

One, the Oracle data dictionary is composed of the following views mainly:1.user ViewUse User_ as a prefix to record information about user objects2.all ViewAll_, which is used to record the information of the user object and the object information that is authorized to access.3.DBA ViewPrefixed with Dba_ to record information for all objects of the DB instance4.v$ ViewPrefixed with v$, used to record perfo

created and only contains information about the currently connected instance. Note that each V $ view contains similar statements: where inst_id = USERENV(’Instance’) Restrict the information of the current instance returned. Starting from GV $ FIXED_TABLE and V $ FIXED_TABLE: SQL> select view_definition from v_$fixed_view_definition where view_name=’V$FIXED_TABLE’; VIEW_DEFINITION -------------

1. List list=[' Jack ',' Bob ',' Harry ',' micle ', with brackets in the list, the elements in the list can be modified 2. Tuple touple = (10,34,56,22), tuples are represented by parentheses (), elements in tuples are not mutableOutput of the result:3. Dictionary dictionary={1: "Jack", 2: "Harry", 3: "Jimmy"}, accessing data with key values, variable elements

,'a0123456789',' ')) intoV_len fromdual; the whileV_indexV_len+1Loop - SELECTRegexp_substr (V_dict_text,'[[: alnum:]]+',1, V_index) intoV_temp1 fromdual; - SELECT TEXT intoV_temp2 fromA1WHEREId=V_temp1; -V_result:=Concat (Concat (V_RESULT,V_TEMP2),','); +V_index:=V_index+1; - EndLoop; + RETURNSUBSTR (V_result,0, Length (V_result)-1); A EndConverter; at - //test results, such as successful conversion of dictionary values to text va

In fact, many versions of SQL Server data dictionary have been circulated on the Internet, but I believe this should be the most comprehensive, this statement includes the table, field, field type, field length, whether it is blank, whether to increment the field, index name, index location, index type, primary key, foreign key, and so on; the corresponding data

Transferred from: Access to the data dictionary view of the database is usually relatively fast, because Oracle has made special optimization work, but sometimes, when several data dictionaries are associated, CBO is not so intelligent, and sometimes it provides some very inefficient execution plans. For example, when trying to construct a large table, we want to

Python saves the dictionary content to the mysql instance code, pythonmysql This article mainly studies how python saves dictionary content to mysql and shares the implementation code. The details are as follows. 1. Background The project needs to use python to store dictionary