normalization

问题 How do I get this mysql database in better 1NF or 2NF form? I tried my best to remove redundant data. It appears there is redundant data still in "Prof_Dept" 回答1: The schema looks strange. How can a Department by a child of Professor_Dept (with the Professor_DeptID FK in it)? That means there is no "Science faculty". You would be storing professor john's science department professor john's physics department professor tom's physics department etc I think the tables should be Professor

问题 Hi i have a most common situation of inserting a client order into my SQL database. I have created an order header and order detail tables in the db and i am trying to insert a single header record and multiple detail lines corresponding to that header record (the PK and FK constraint is the headerID). Currently, i insert my header record, then query the db for last created headerID and use that ID to insert my detail lines by looping through grid for example. I know this is a stupid way for

问题 I would like to ask about a question relating to normalization. I have 2 PKs, VIN and Reg_no. VIN is the Vehicle ID Number and Registration number is the car plate number. I have an attribute called current odometer. Does it have a partial dependency or a full dependency on the 2 PKs? 回答1: I have 2 PKs, VIN and Reg_no. VIN is the Vehicle ID Number and Registration number is the car plate number. You have two candidate keys. VIN is unique; the plate number is also probably unique. (But it

问题 I had trying to insert the following mapping in the the index to support the search feature. Index setting : url: PUT http:/localhost:9200/indexname { "settings": { "analysis": { "normalizer": { "my_normalizer": { "type": "custom", "filter": ["lowercase"] } } } } } Mappings : url: PUT http:/localhost:9200/indexname/typename/_mapping { "org-5-table": { "properties": { "GroupName": { "type": "text", "fielddata": true, "fields": { "keyword": { "type": "keyword" }, "lowcase": { "type": "keyword",

问题 I am designing a SQL database that needs to be a five-table database to meet Air-Crewe’s requirements. I have the following so far: I have this for UNF: CrewID, Crew Type, Title, Forename, Surname, Gender, CAALicenceNum, FlightID, FlightNum, IATADep, IARAArr, Date, SchDep,SchArr, Comments, A/CType, A/CReg, A/CManuf I have this for 1NF: TBLCrew(CrewID[PrimaryKey], CrewType, CrewTitle, Forename, Surname, gender, CAALicenceNum, FlightID*) TBLFlight(FlightID[PrimaryKey], FlightNumber, IATADep,

问题 Below is a preview of the type of list I am talking about. What is going to happen is each user is going to have their own list that they can create. They will be able to modify the headings (Maintenance, Tire Services) and modify each item and add to it and add more rows. Here is a database design I had in mind: titles: id - name - user_id 1 - Maintenance - 1 2 - Tire Services - 1 services: id - title_id - name - user_id 1 - 1 - Wiper Blades - 1 2 - 1 - Cooling System - 1 3 - 2 - Tire

问题 I have a table called Users that has a growing list of preferences. These preferences could includes ReligionId (which would key off to another table that contains the list of religions). The list of preferences is growing. I want to split it off the Users table into 2 tables. The strategy that I think would work well is to make a separate table called UserPreferences . I'm wondering if doing this is in line with the rules of normalization. Here is an illustration to make things a bit more

问题 I am trying to normalize a dataset, update an array index, and then denormalize the data. I'd like to change a P.O. at on a header line and have the change propagate to a linked order. The data model is as follows: let numSet = 0; let numLine = 2; let data = [ { "order": { "po_no": "original-po" }, "items": [ { "header": { "po_no": "keep-this-value", "set_no": 0 }, "line": { "id": "A123", "line_no": 1 } }, { "header": { "po_no": "update-with-this-value", "set_no": 0 }, "line": { "id": "B234",

问题 I have a mat file with a structure that looks like this: How do I normalize the data and save it as a .dat file (ascii) 回答1: I assume that you want to normalize each column. There are two ways you can normalize: (1) Set minimum to 0 and maximum to 1 dataset = bsxfun(@minus,dataset,min(dataset)); dataset = bsxfun(@rdivide,dataset,max(dataset)); (2) Set average to zero, standard deviation to 1 (if you don't have the Statistics Toolbox, use mean and std to subtract and divide, respectively, as

问题 I am trying to create a normalization value for a variable I am working with based on individual conference means and SDs. I found the conference means using the function: confavg=aggregate(base$AVG, by=list(base$confName), FUN=mean) And so after getting the means for the 31 conferences, I want to go back and for each individual player put these means in so I can easily calculate a normalization factor based on the conference mean. I have tried to create large ifelse or if statements where