When you execute an SQL query and UPDATE multiple rows of records, we usually use the following SQL statement to UPDATE the field value: 1 UPDATE mytable SET myfield = 'value' WHERE oth
SQL does not repeatedly search for data and concatenates a column of multiple rows into one row. SQL multiple rows
See the following table:
Table Name: Test
ID
RowID
Col1
Col2
1
1
A
A
2
when '2' Then 1.10 when '3' Then 1.15 Else 1.08End; quit;8: Change the columns in the tableTo add, drop (delete), or modify columns in a table, use the ALTER table St Atement. /* add column */ proc SQL; alter table work .payrollmaster4 add Bonus num format= comma10. 2 , level char (3 /* Delete Column */Proc SQL; Alter Table Work . Payrollmaster4 Drop Bonus,lev
a.slid=b.fi_inst)Set Blzt=ft_lstate;(3) Merge Update method (faster when associating fields with non-primary keys)Grammar:MERGE into table_name alias 1USING (Table|view|sub_query) alias 2On (Join condition)When matched thenUPDATESET Col1=col_val1,Col2=col_val2When isn't matched thenINSERT (column_list) VALUES (column_values);Scenario: Select data in Alias2, each with the ALIAS1 on (join condition) comparison, if matched,
) Merge Update method (faster when associating fields with non-primary keys)Grammar: MERGE intoTABLE_NAME Alias1USING (Table|View|Sub_query) Alias2
on(Joincondition) whenMatched Then
UPDATE
SETCol1=Col_val1, col2=Col_val2 when notMatched Then
INSERT(column_list)VALUES(column_values); Scenario: Select data in Alias2, each with the ALIAS1 on (join condition) comparison, if matched,
The program that raised the edit record tonight has tried several times and the results are incorrect. Let's take a look and find that the program stops running after a certain statement. This time I have experience. I wrote a statement on error goto in the process. In the Error Processing Section, stop it and then press the following text in the prompt window to get the following results:
? Error
The key column information is insufficient or incorrect. Up
To update multiple rows:
There are many steps, but the efficiency is relatively high:1. Create Table temporary table value (select a. ID, A. Name, B. Name,... from Table1 A, Table2 B where a. ID = B. ID)2. delete records in Table 1. Do not drop3. insert into Table1 select the field you need from the temporary table.
Select * From tb_ai03
Create Table tb_ai
Label:---restore content starts---[This afternoon to accept an emergency small task, is a set of record statistics, the chess game player's two records in a row of the display, into the database after the first thought is the row to the column, but at the beginning felt wrong, and later wrote half really wrong, later on the Internet query for half a day more than a row of rows and more columns, Found to write algorithms and write functions, see the re
Tags: english sep chinese img Parallel src segmentation Math Group BYDatabase structure And I want to make the same person's different grades into this person. displayed on different columns of this line, this time divided into 2 shows: The first shows----"Multiple rows to one column" (the merged data is on the same column): SQL is as follows: The second show
Usage scenarios:For example, you need to query all student numbers with scores greater than 95, separated by commas into a string, from the Student score table.To prepare the test data:CREATE TABLE score (ID int,score int)INSERT into score values (1,90)INSERT into score values (2,96)INSERT into score values (3,99)It is now necessary to query the result string "2,,3" with a single statement.The SQL Server statements are as follows:Select substring ((SE
Example of a trigger codes:
Code of the insert, delete, and update trigger:
Code highlighting produced by Actipro CodeHighlighter (freeware)http://www.CodeHighlighter.com/-->-- DBO. trgroups. SQL
If exists (
Select * From sysobjects where
Name = 'trgroups' and type = 'tr ')
Begin
Drop trigger trgroups
If not exists (
Select * From sysobjects where
Name = 'trgroups' and type = 'tr ')
Print 'drop trgroups s
(8000)
Select @sql =isnull (@sql + ' union All ', ') + ' select name, [Course]= '
+quotename (name, ' "') + ', [score] = ' +quotename (name) + ' fro M TB ' from
syscolumns
WHERE name!= ' name ' and id=object_id (' TB ')--table name TB, not including other columns named name ORDER by
Colid
exec ( @sql + ' ORDER by name ')
go 3. Using
Label:1. Get the last bar to insert dataLAST_INSERT_ID ();2. Gets the number of update impact rows.Row_count ();mysql> UPDATE T
, SET address = ' beijing111 '
, WHERE id = 1
, and NAME = ' Yubowei ';
query OK, 1 row affected (0.30
sec)
Rows matched:1 changed:1 warnings:0
mysql> C14/>mysql> SELECT Row_count (); +-------------+ | Row
Sometimes in some systems, we need to use SQL statements to display data in one-to-multiple Relational Tables in the form of a row of each record. This article uses functions and cursors to implement this function.
The example table is described as follows:
A user table and document table
Now you want to implement the following functions to query the synthesis of each user and the corresponding document na
To Merge multiple rows into one project, you must merge multiple rows into one project.
The table structure is as follows:
Name null type
--------------------------------------
N_sec_code not null char (6)
C_researcher_code not null varchar2 (20)
This table stores the ing data between "stock" and "researcher". Gener
Document directory
Example
Stuff:
For xml path
References
Example
Yesterday I encountered an SQL Server problem: I need to write a stored procedure to process data in several tables. The problem is that I want to splice multiple rows in one column of a table into one row, for example, a table has two columns of data:
Category
Name
A
To Merge multiple rows into one project, you must merge multiple rows into one project. The table structure is as follows: NAME Null Type ----------------------- ----- N_SEC_CODE not null char (6) C_RESEARCHER_CODE not null VARCHAR2 (20) This table stores the ing data between "stock" and "researcher, generally, for the
Problems that occur when you update a table that does not have a primary key set:Cause of the problem:Most of this is due to the absence of a primary key (PK) that causes several identical data to exist in the same tableWhen the DBMS is stored, only one piece of data is stored, because the DBMS is optimized to reduce data redundancy. So deleting or updating a duplicate data is reachingWorkaround:It is recommended to set the primary key to check for th
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