smf records

how much in thousands of records, there are some same records, how can you use SQL statements, delete duplicates1, look for redundant records in the table, duplicate records are based on a single field (Peopleid) to determineSELECT * from peoplewhere Peopleid in (select Peopleid from People GROUP by Peopl

Tags: delete name cat SQL database format string count expression BlurI. Adding table records (equivalent to inserting table records) 1. Format: Insert [INTO] table_name (field name ...) Values (Value ....); Add a record Insert [INTO] table_name (field name ...) VALUES (value 1 ...), (the value of 2 ...), and so on. .......; Add more than one record 2, note: How many field names to write the number of cor

Label: four querying records The most common use of records in a data table in a MySQL database is a recorded query, and the records in the Operation data table are mostly recorded queries. Find The syntax structure of the record is: SELECT select_expr [, select_expr ...] [ From Table_refereneces [WHERE Where_condition] [GROUP by {col_name | position} [ASC |

The ORACLE tutorial is: quickly delete duplicate records in oracle. When I was doing a project, a colleague accidentally duplicate all the data in a table while importing data. That is to say, all the records in this table have a record. This table has tens of millions of data records and is a production system. That is to say, You cannot delete all

MySQL query repeated records in the table (1) 1. Search for redundant duplicate records in the Table. Repeat records determine the select * from peoplewhere peopleId in (select peopleId from people group by peopleId having count (peopleId)> 1) 2. Delete unnecessary duplicate records in the Table. duplicate

Question: How to delete a record with the same field and leave only one record. For example, the table test contains the ID and name fields. If there are records with the same name, only one record is left, and the remaining records are deleted. The content of the name is not fixed, and the number of identical records is not fixed. Use SQL statements to delete du

Delete all If you are deleting all the data for a table and do not need to roll back, use TRUNCATE to OK. About Trancate See here http://blog.csdn.net/gnolhh168/archive/2011/05/24/6442561.aspx Sql> TRUNCATE TABLE table_name; Conditional Deletion If there is a condition for deleting the data, such as delete from tablename where col1 = ' Lucy '; At this time, in addition to Gazzo, you can delete the Add no logging option, do not write log speed up the deletion Quote SB. "The tens of millions of-

There is A field ldquo; name rdquo; in Table A, and the value of ldquo; name rdquo; between different records may be the same, now you need to query the records in the table, and the ldquo; name rdquo; value has repeated items; SelectName, Count (*) fromAGroupByNameHavingCount (*) gt; 1. If the gender is also the same, for example, the field "name" exists in table ", The "name" value may be the same

This tutorial provides two SQL statement codes for deleting duplicate records. One is to use wherein to query duplicate records and then delete them. The other is to use innerjoin to delete duplicate records on the instance. This tutorial provides two SQL statement codes for deleting duplicate records. You can use whe

Build a Table statementCREATE TABLE Persons(PersonID int,LastName varchar (255),FirstName varchar (255),Address varchar (255),City varchar (255));INSERT into Persons values (1, ' A ', ' AA ', ' aaa ', ' aaaa ');INSERT into Persons values (1, ' A ', ' AA ', ' aaa ', ' aaaa ');INSERT into Persons values (1, ' A ', ' AA ', ' aaa ', ' aaaa ');INSERT into Persons values (1, ' A ', ' AA ', ' aaa ', ' aaaa ');INSERT into Persons values (2, ' a ', ' AA ', ' aaa ', ' aaaa ');INSERT into Persons values (2

In the recent project, you need to copy several dump files (text format, 1 ~ 2 GB) records are imported into the MySQL database. Due to the large data volume (millions or tens of millions of records), there are insert records and update records, the insert/update speed is slow. At the beginning, a single SQL statement

Oracle databases contain many duplicate items because they do not have any constraints. The question now is how to delete these repeated items. Repeat records only keep one of them. The following table creation statement Create table message_student3 ( Stu_id integer not null, -- the table has no uniqueness constraint. Stu_number varchar (30 ), Stu_name VARCHAR (10) not null, Stu_age NUMBER (2) NOT NULL ); Insert into message_student3 VALUES (1, '2013

Select rowcnt from sysobjects s inner join sysindexes IOn S. [ID] = I. [ID]WhereI. [name] = table name and S. xtype = 'U'Previously, I also associated sysobjects. It is also possible to do this without association. It actually exists in the sysindexes table.Select rows from sysindexes where id = object_id (table name) and indid in (0, 1) There are two types of indexes: tered and non-clustered. The index pages are arranged in B-tree mode. The clustered index will sort the columns set as indexes

One of the historical records of it: Gary kildell, father of DOS |Another 2: Apple founder Steve Wozniak |It history 3: angry Jerry Sanders |Historical it records: Founder of MITS and father of Personal Computer Edward Roberts |Story 5: Father of the mouse and master of human-computer interaction Doug Engelbart | It historical records serialized 6: Jean amdal, t

In most applications, it is common to return a large number of qualified records. The most typical method is to search. In the search application, the user gives the search criteria and the server finds the matching records. However, a search usually returns a large amount of data records. If you are on a webpage, the page is usually implemented by pagination. Th

The following article mainly describes the actual comparison between the Oracle database and DB2 and MySQL with the first 10 records. The following article mainly uses Oralce as an example to explain their differences, the following is a detailed description of the article. I hope you will get some benefits. 1. Best Choice: use analysis functions row_number()over(partitionbycol1orderbycol2) For example, if you want to retrieve-

We often encounter the need to delete repeated records in a data table. Below I will summarize several methods that can delete Repeated Records and help to improve efficiency. For more information, see. We often encounter the need to delete repeated records in a data table. Below I will summarize several methods that can delete Repeated

This section focuses on the ExtJS4.2 grid to automatically check the specified records, automatically check all records, reverse selection, that is, the table grid after loading data automatically select the qualifying record line, sample picture:650) this.width=650; "alt=" ExtJS4.2 grid knowledge Point Six: Automatically select the specified record, automatically check all

Data | Database One, description Most end users require that their web scenario be able to provide some kind of reporting capability. With HTML and ASP, you can easily provide the ability to list records in a table and browse through them individually. But users often require the ability to select a category of records through a Drop-down list box (or other option), or they want to be able to use some sort

will carry out a physical sub-table, otherwise every day millions records, a year down is hundreds of millions of. So, the structure of our table is this:CREATE TABLE[dbo]. [His20140822] ([No] [bigint]IDENTITY(1,1) not NULL, [Dtime] [datetime] not NULL, [Mgrobjid] [varchar]( $) not NULL, [Id] [varchar]( -) not NULL,[Value] [varchar]( -) not NULL,CONSTRAINT[pk_his20140822]PRIMARY KEYCLUSTERED ([No]ASC) with(Pad_index = off, Statistics_norecompute = of