Mysql ninja tricks -

-

संभव डुप्लिकेट:

हाय,

आपका माइस्केल निंजा ट्रिक्स क्या हैं? क्या विशेषताएं अतिरिक्त विशेष हैं?

मैं ORDER BY FIELD से शुरू कर रहा हूं, जिससे आप किसी विशेष क्रम में सॉर्ट कर सकते हैं, जैसे: 

  ग्राहक से ORDER द्वारा FIELD (customer.priority, 1, 2, 3, 0) से यूआरएल का चयन करें

इस तरह की विशेषताएं mysql दस्तावेज़ीकरण में खोजना कठिन है।

इसे लाओ!

क्वेरी निष्पादन योजना को प्रोफाइल करने के लिए EXPLAIN का उपयोग करें

< / html>

Comments

Post a Comment

Popular posts from this blog

windows - Heroku throws SQLITE3 Read only exception -

-
After I deploy the app to Heroku, I have to run migration scripts and get this error message ... ITES \ padrino \ prophetmargin & gt; Heroku Rack AR: Rack mutated! SQLite3 :: ReadOnlyException: only one try to write database to read: CREATE TABLE "schema_migrations" ( "version" varchar (255) NOT NULL) /disk1/home/slugs/215264_925fd2c_65a3/mnt/.bundle/gems/gems/ padrino-core- is 0.9.11 / lib / padrino-core / cli / rake.rb: 9: in `init ' how can this be? I also tried to run Heroku dbpush SQLite: //db/my-db.db and that did not work Horoku sqlite3 but using postgres does not do. I'm not sure why you are receiving this error, however, as I have used sqlite3 in development and when pushing it into its travel, they do some magic which migrates to postgrads. I'm absolutely sure how Heroku does 'backwash' this database but it seems that this is happening to you because it's the SQLite db file which is obviously due to Heroku's...
Read more

lex - Building a lexical Analyzer in Java -

-
I am currently learning lexical analysis in compiler design. To know how a lexical analyzer actually works, I am trying to build myself. I am planning to make it in Java The input to the lexical analyzer is a .tex file that is of the following format. \ section {script} {intro} \ section {Scope} arbitrary text \ section {relevance} uncontrolled text \ subdivision (profit) arbitrary text \ subsubsection {in real life} \ subdivision {Ingredient} \ end {document} The output of the lecture may be a table of contents with a page number in another file. 1 Introduction 1 1.1 Scope 1 1.2 Relevance 2 1.2.1 Benefits 2 1.2.1.1 Real life 2 1.2.2 loss 3 I hope that This problem is within the scope of Language Analysis Read the .exe file and check '\' and continue to check whether it is actually on search In the sectioning command is set to indicate whether or not a flag variable is the type of sectioning. I hope the above approach will work for the construction of Lexa...
Read more

python - rename keys in a dictionary -

-
I want to change the names of keys in a dictionary which are ints, and I need them so that the inputs with key zero They can sort correctly. For example, my keys are like this: '1', '101', '11' and I may need them: '001', '101', '011' What is doing, but I know that there is a better way tmpDict = {} in the ADC for the old: t MpDict ['% 04d'% int (olden)] = addict [oldkey] New controlled = tmpDict You are going wrong about this if you want to draw entries on a line in a specific way, then you have to sort on the extraction. for sorted (D, key = int): print '% s:% R'% (k, d [k])
Read more