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main field = @idFetch cur_rows into @id, @maxEndClose Cur_rowsSET ROWCOUNT 0Method TwoThere are two meanings of duplicate records, one is a completely duplicate record, that is, all fields are duplicated records, and second, some key fieldsDuplicate records, such as the Name field, and the other fields may not be repeated or repeated can be ignored.1, for the first kind of repetition, easier to solve, usingSELECT DISTINCT * from TableNameYou can get a result set with no duplicate records.If the
and truncate carefully, especially when there is no backup. Otherwise, it's too late to cry.6. On the use, want to delete some data rows with delete, note with the WHERE clause. The rollback segment should be large enough. If you want to delete a table, delete all of the data by dropping it to keep the table. If it is unrelated to the transaction, use truncate. If it is related to a transaction, or if you want to trigger trigger, or delete the fragment inside the table, you can use truncate to
Label:How is duplicate data removed from the Oracle database? When working with data tables, there are often duplicate data, so how do you delete them? Let's talk about removing data duplication from Oracle databases. There are two ways we are going to talk today.First, according to rowID come and go heavy.We all know that in Oracle database tables, each record has a unique rowid to identify, which allows us to go to the heavy query conditionWe have a test table, first of all, if we're going to
1), you can delete them as follows[SQL]View PlainCopy Select Distinct * to #Tmp from tableName Drop Table TableName SELECT * into tableName from #Tmp Drop Table #Tmp This duplication occurs because the table is poorly designed and the unique index columns are added to resolve.2, this kind of repetition problem usually requires to keep the first record in the duplicate record, the operation method is as followsSuppose there is a duplicate field name,address, which r
Label:In a database table, duplicate values may be included. That's not a problem, but sometimes you might want to just list different values (distinct). Keyword DISTINCT is used to return only different values. Table A: 1. Acting on a single rowSelect distinct from A The following results are performed: Acting on multi-column Example 2.1Select distinct from A The following results are performed: In fact, it is the same way that access and SQL Server support it, depending on the name and ID t
Tags: unique values Group Stat author A10 sage how multiple artReference: Http://blog.sina.com.cn/s/blog_6c9d65a10101bkgk.htmlHttp://www.jb51.net/article/39302.htm 1, use distinct to weight (suitable for querying the total number of the whole table)There are multiple schools + teachers to contribute, need to count the total number of authorsSelect COUNT (author) as Total from files each author has a lot of contributions, there are duplicate records here. Select distinct author from files; It is
Label:CREATE TABLE #tp(Headerno VARCHAR (10),Machineno VARCHAR (10),Descrption NVARCHAR (20),Artno VARCHAR (20),Qty INT,Repartno varchar (20),Repqty INT) INSERT INTO #tp SELECT ' HD01 ', ' 0101520 ', N ' battery problem ', ' 102020 ', 2, ' 102020 ', 2INSERT INTO #tp SELECT ' HD01 ', ' 0101520 ', N ' battery problem ', ' 101010 ', 2, ' 202020 ', 2INSERT INTO #tp SELECT ' HD01 ', ' 0101520 ', N ' battery problem ', ' 126888 ', 2, ' 102020 ', 2INSERT INTO #tp SELECT ' HD02 ', ' 01012221 ', N ' d mo
--Under the sql2005, sql2000 can notCREATE TABLE TB (ID int,name varchar (4))Insert TB Select 1, ' AA 'UNION ALL Select 1, ' AA 'UNION ALL Select 2, ' BB 'UNION ALL select 3, ' BB 'UNION ALL Select 4, ' CC 'UNION ALL Select 1, ' AA 'UNION ALL Select 4, ' CC 'Delete a From(select Id,name,rn=row_number () over (partition by id,name order by ID) from TB) a where rn>1SELECT * FROM TBOriginal: http://blog.csdn.net/hzvcan/article/details/4862927SQL Server Data ded
Tags: mongodbRecently wrote a crawler tool, the data stored in the Web site MongoDB, because the data are duplicated, so I set up the database when the index, the following is my step, the set name is Drugitem,Here is the collection:I want to create a unique index for the name field because I want to ensure that name is not duplicated:In this way I run the program to find that the data is much less than the original set unique index, I carefully review the Discovery program in the Name field is
Business Requirements:A table has the Id,n1,n2,n3 field, which is a new empty table,Table B has id,n1,n2,n3,n4,n5 fields, such as old tables containing data,Now the record of the N1,N2,N3 combination in B table is re-imported into a table, and a table primary key is also entered valueScenario: The records of B table after the query to go to the weight, while the results of the records are numbered, the sequence number as a table to insert the ID value, SQL statement as follows:INSERT INTO A表(id,
This article describes how to use the yahoo Exchange Rate Interface to implement real-time exchange rate conversion. For more information, see the following code: Function getExchangeRate ($ from_Currency, $ to_Currency) {$ amount = urlencode ($ amount); $ from_Currency = urlencode ($ from_Currency); $ to_Currency = urlencode ($ scheme ); $ url = "download.finance.yahoo.com/d/quotes.html? S = ". $ from_C
Recall (recall rate); Precision (accuracy rate); F1-meature (Comprehensive evaluation index); These parameters are often used in information retrieval (such as search engines), natural language processing, and detection classifications.Precision: The percentage of information that is detected that is correct or relevant ( that is, what you want)(Number of positive samples predicted as a proportion of the to
What is the use rate of PF? Pf:page file, pagefile (virtual memory) PF Usage: value of the amount of space that virtual memory has already used What is the reason for the high utilization rate of PF Although PF is called virtual memory, it will still occupy a lot of space when it is too large, and it will have a great impact on the speed of the computer when the PF usage is too high. The reasons fo
Original article published on 20:49:49 In the previous article, I briefly introduced someTestMost of the tools related to coverage are not used by the author, So I simply searched the relevant information from the Internet and sorted it out. For details about the previous article, see test coverage rate 4-Test Coverage Rate tool summary. This article mainly discusses howImprove test coverage. In fact, the m
JAVA exercise-calculate the circumference rate π and circumference rate π for given precision Returns an approximate value of the circumference rate π with a given precision. Given formula: π/4 = 1-1/3 + 1/5-1/7 + 1/9 -... 1 public static void main (String [] args) {2 System. out. println ("Enter the precision of π (the number of digits after the decimal point
Python method for calculating pi of circumference rate, python pi of circumference Rate The example in this article describes how to calculate the circumference pi of python. Share it with you for your reference. The details are as follows: from sys import stdout scale = 10000 maxarr = 2800 arrinit = 2000 carry = 0 arr = [arrinit] * (maxarr + 1) for i in xrange(maxarr, 1, -14): total = 0 for j in xrange
1. Under the Standby page, click "Application". 2. Click on "s Health". 3. Click "Next". 4. After reading the terms and conditions, select "I agree", and then click "Next". 5. Choose whether to log in to the Samsung account or skip it according to your needs. (Take "Skip" for example) 6. Enter your basic information (name, sex, birthday), click "Next". 7. Enter your height and weight and click "Next". 8. Set up your active
constructed. If it is, it is a common URL and saved in the file.Solution 2: if a certain error rate is allowed, you can use the bloom filter. The 4G memory can be approximately 34 billion bits. Map the URLs in one file to the 34 billion bits using the bloom filter, read the URLs of another file one by one, and check whether the URLs are consistent with the bloom filter. If yes, the URL should be a common URL (note that there will be a certain error
Let me introduce you to an example, which is the RMB exchange dollars, you can refer to friends. As shown in Iphone6 plus we open the "stock Market" APP, click on the list button in the lower right corner to add items, enter "Cny=x" in the search box, and then click "Add" so we will see that the RMB exchange rate for US dollars appears in the stock list. This allows you to see the relevant parameters. Of course, if we want to add other, we need to
The current use of the most common display is just two, CRT and LCD display, because the working principle of different, on the screen refresh rate settings are also different, in general, CRT monitor set 80-85 Hz is advisable, set too low will have damage to eyesight, set too high may speed up the aging of the display. for an LCD monitor, set to the default 60 Hz is advisable. How to adjust the screen refresh
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