how to update multiple rows in sql

the data is updated, and the WHERE clause ensures that only 3 rows of data are executed. If you update multiple values, you need to modify them only slightly: The code is as follows UPDATE Categories SET Display_order = case ID When 1 THEN 3 When 2 THEN 4 When 3 THEN 5

1 THEN 'value'WHEN 2 THEN 'value'WHEN 3 THEN 'value'ENDWHERE id IN (1, 2, 3) Here we use the case when tip to implement batch update.For example: Copy codeThe Code is as follows:UPDATE categoriesSET display_order = CASE idWHEN 1 THEN 3WHEN 2 THEN 4WHEN 3 THEN 5ENDWHERE id IN (1, 2, 3) This SQL statement indicates that the display_order field is updated. If id = 1, the value of display_order is 3. If id = 2, the value of display_order is 4, if id = 3,

This article illustrates the way Android implements SQLite Add, update, and delete rows. Share to everyone for your reference, specific as follows: The Sqlitedatabase class exposes specific methods, such as inserts, deletes, and updates, which wrap the SQL statements required to perform these actions. However, the Execsql method allows you to execute any valid

How to efficiently split a field into multiple rows I originally split a field in the table into multiple rows, such as aaa and bbb into aaabbb. Now the test is as follows: [SQL] witht1as (select3c1, eee, fff, gggc2fromdualUNIONALLselect2c1, ccc, dddc2fromdualUNIONALLSELECT1

The following is a test example.1. Create two temporary tables and input test data:Copy codeThe Code is as follows:Create table # temptest1(Id int,Name1 varchar (50 ),Age int)Create table # temptest2(Id int,Name1 varchar (50 ),Age int) The following table data is queried: # Temptest1 # temptest2 2. Now we need to update the age in # temptest2 to the corresponding age in # temptest1. In fact, the age of ID 1 in [Table 1] is changed to 19, and the ag

The following is a test example. 1. First create two temporary tables and input test data: Copy Code code as follows: CREATE TABLE #temptest1 ( ID int, name1 varchar (50), Age int ) CREATE TABLE #temptest2 ( ID int, name1 varchar (50), Age int ) The table data at this point in the query is: #temptest1 #temptest2 2. It is now time to update the age in the #temptest2 to the corresponding #temptest1.

error occurs: "The modified or deleted row value cannot be changed to a unique row, or multiple rows (X rows) have been changed. It turns out that I forgot to add the primary key when creating the table, but now I cannot delete it. I can enter something in it, but I cannot enter it, and an error is returned. No way ~ Baidu ~ Various solutions finally found the

Normally, we use SQL to execute INSERTINTO 'tabale '('name') VALUE (name). If php needs to execute such SQL statements cyclically, therefore, execute an SQL statement below to insert multiple rows of records. INSERTINTO 'tabale '('name') VALUE (name), (name) How many pieces

by Field 1, Field 2, Field 3 having COUNT (*) > 1) Where: Field 1, Field 2, Field 3 refers to the three fields that need to establish a unique constraint, selfid refers to one of the self-increment fields in tables table. 2. Delete duplicate records and keep only the Selfid minimum records, that is, the first inserted records:[SQL]View Plaincopy DELETE from dbo. Tablesign WHERE Selfid in (SELECT Selfid from dbo. ) T

Mysql uses group_concat () to merge multiple rows of data into one row, and mysqlgroup_concat Assume that two tables a, B, and B are associated with table a through the field id, and table a and table B are one-to-many relationships. Assume that table B has a field name. Now you need to query the records in Table a and obtain the name information stored in Table B according to the regular query, the number

Why can't foreach retrieve only one row when using the mysqli class, while loop fetch multiple rows of data? I am a newbie. if you have any questions, please use the mysqli class. the data table test contains five rows of data. The foreach function can only retrieve the first row. None of the other rows can be retrieve

();Return DT;} Private void collectdatafromgrid (){Datatable dt = This. currentdata;If (Dt. Rows. Count> 0){Dropdownlist ddlst = This. Maid [Maid]. cells [0]. findcontrol ("dropdownlist1") as dropdownlist;DT. Rows [DT. Rows. Count-1] ["ID"] = ddlst. selectedvalue;DT. rows [DT. ro