how to update multiple rows in sql

statement.In general, it is a relatively efficient way to use "small table driver Big table" when connecting between tables, that is, when loops join, loop the small table, drive the large table by loop, and then produce the query result set.The performance surface, which is caused by the order of the driving order between the tables, has a very significant improvement in performance after forcing a drive sequence.But further thinking, why is SQL Ser

Exporting data in SQL Server tables to multiple Excel files in batches by conditions is what we will introduce in this article. In an SQL Server database operation, you need to export a table with hundreds of thousands of rows of data into an xls file by category. Each category has one xls file. Export and save the dat

Import DBDbutil = DB (' 127.0.0.1 ', 3306, ' root ', ', ', ' test ')rs = Dbutil.query ("Select Id,age from Table_b")For row in RS:(idv,age) =rowPrint (Idv,age)update_sql= "Update table_a set age= '%s ' where id= '%s ';"% ( AGE,IDV)Print Update_sqlDbutil.update (Update_sql)print ' over ' In fact, a single SQL statement can be done Look at the code, it is simple, so the internet search the MySQL c

1. Create a test tableCreate table t_user (ID int identity primary key,UserID varchar (50) not null,UserName varchar (50) null,DeptID int not null,Phone varchar (50) null,Fax varchar (50) null) Create table t_dept (ID int identity primary key,DeptName varchar (50) null,Phone varchar (50) null,Fax varchar (50) null) INSERT t_userSelect n '001', N 'zhang san', 1, N '000000', N '000000'UNIONAll select n '002 ', N 'Li si', 2, N '000000', N '000000'UNIONAll select n '003 ', N 'wang wu', 2, N '000000'

Tags: amp ext tab parameter to could not length MySQL ValSuppose the parameter SQL already contains more than one SQL statement. such as SQL = "INSERT INTO table1 (...) Values (...); Update table2 set a=1; ";const BOOL Cdboperator::multiquery (const std::string SQL, std::str

OUTER join keyword.For example, in the database "Jeweler Marketing System", the "Consumer information" and "Jeweler information" tables are fully connected to the consumers and jewelers in the same city.SELECT consumer name, consumer address, consumer city as city, jeweler name, jeweler's addressFrom customer information A full OUTER JOIN jeweler information BOn A. The city where the consumer is located =b the jeweler's cityafter execution, the query's results contain six

Note: The update operation, first gets the object, after the modification operation, directly calls the SubmitChanges () method to commit. Note that this is in the same DataContext, for the different Datacontex see the following explanation.1. Simple FormCustomer cust = "ALFKI""Vice President" ;d B. SubmitChanges ();Statement Description: Use SubmitChanges to persist the updates made to the retrieved one customer object back to the database.2.

Tags: process _id update create STS Delete field name stored procedureTransferred from: http://www.maomao365.com/?p=5277Summary:Here's how to add a new field to a table in the "on-line system". System deployment scripts, adding columns to the method:In system script publishing, how to modify and add a stored procedure custom function view, we usually use the following steps to write such a script1 Determine if the object (stored procedure custom

specified in the left outer clause, not just the rows matched by the join column. If a row in the left table does not match a row in the right table, all the selection list columns in the right table in the row of the associated result set are null ).(2) SQL statementsSelect * From Table1 left join Table2 on table1.id = table2.id------------- Result -------------ID name ID score----------------------------

(@I_WHILE_XUEHAO >=6080 and @I_WHILE_XUEHAO Data for the "Composite score Table": 3.1.1. Create a view associated with 3 tables: Use [Sql-li] go CREATE VIEW shitu_ffenshu_xinxi (name, student number, average score, total score, class, birth date ) as SELECT top X. Name, F. School Number, Z. Average score, Z. Total Score, X. class, X. Date of birth from[dbo]. Xinxin_tab as X INNER JOIN [DBO]. Fenshu_tab as F on X. School number =f.

Label:PL/SQL Developer manages multiple sets of databases and connects multiple sets of databases as a unified interface platform. 1.. 1, class SQL Plus Windows: File->new->command window, this is similar to Oracle's client tool SQL Plus, but it is much more useful. 2, set

Tags: manipulating style max snippet multiple statement results one SouthOriginal: SQL Server updatable subscription Queue Reader Agent error: An attempted insert or update has failedToday it is found that the Queue Reader Agent keeps trying to start but always goes wrong:The contents are as follows:This may be caused by another problem that has just been dealt w

) as number of sums, summary from Agroup by category order BY category Desc Example 3 will prompt for an error after execution, such as. This is a point to note that the field specified in select is either to be included in the group by statement, as a basis for grouping, or to be included in an aggregate function. 6. Group by all Example 4 Select category, Summary, sum (quantity) as number of and from Agroup by all category, summary In Example 4, you can specify a summary field because the "su

One of the new functions provided by Drupal 7 is the ability to use the Query Builder and Query Objects Query Builder to construct Query Objects without the need to write original SQL statements in the code, one is to improve code readability, and the other is to be compatible with all databases.Insert a single record The code is as follows: Copy code Db_insert ("table"

If the MS-SQL combines two or query results into a single result set that contains all rows of all queries in the Union query, a common method 1. Use the Union or union all statement 1. Difference between Union and Union all statements Union combines multiple tables (or result sets) and returns them as a single result set; Union all contains all

One Finecms code triggers Multiple SQL injections Location: /Dayrui/core/D_Member_Home.php 81 rows: $order = isset($_GET['order']) strpos($_GET['order'], "undefined") !== 0 ? $this->input->get('order', TRUE) : 'updatetime desc'; The next 109 rows: $ This-> link-> order_by ($ order ); First, the order is obtained from

Every time you talk about locks and blocks in SQL Server (Locking Blocking): Why do we need to update locks in SQL Server? Before we explain the reasons for specific needs, first I want to introduce you to the next time when the update lock (lock) is obtained, according to its compatibility lock itself is how to deal

Label:The SQL Server UPDATE statement is used to update the data, which gives you a detailed description of the syntax of the SQL Server Update statement, and hopefully allows you to learn more about SQL Server

pre-generated, and if you add dynamic, you need to scan each property's changes each time you update, and then generate an update, which has a slightly more efficient effect. If you don't have a special requirement, it's a good default. If you update multiple records at one time, hibernate will not be able to u

, read 0 times, LOB logic read 0 times, lob physical read 0 times, lob read 0 times.Time: 17026 From the above can be seen, the merge is more than the hash of the operation, that is, the operation of the worktable, more time-consuming should be consumed here. The CPU time is as follows: (239657 rows affected) SQL Server Execution Time:CPU time = 12763 milliseconds, elapsed time = 24520 milliseconds. (23965