mysql update multiple columns

MySQL index usage instructions (single-column index and multi-column index), mysql multiple columns 1. Single Column Index In the performance optimization process, selecting the columns to create an index is one of the most important steps. You can consider using two types o

';Results :' East Boston '3. Add SeparatorsConcat_ws () function, representing concat with separator, which is a delimited string connection Separated by commas, if connected Mysql> Select Concat_ws (', ', ' 11 ', ' 22 ', ' 33 '); +-------------------------------+ | Concat_ws (', ', ' 11 ', ' 22 ', ' 33 ') | +-------------------------------+ | 11,22,33 | +-------------------------------+ 1 row in Set (0.00 sec) Unlike concat, the CONCAT_WS function d

Implementation of different values for mysql batch update and batch update of multiple records bitsCN.com Batch update The mysql update statement is simple. to

Mysql tables are sorted by multiple columns to obtain the first or next entry of a specified value. how can we make it simple? mysql, table name: tblsale, there are two fields, date and index, to determine a sales order (n orders in a day are identified by index). the records in the table are not necessarily discharged

Concatenate the values of multiple queried columns into a string bitsCN.com using SQL. Concatenate the values of multiple queried columns into a string using SQL. MySQL: [SQL] -- Concatenate a single column. first, locate a row, add a comma, and then splice the nex

Label:ref:http://blog.csdn.net/priestmoon/article/details/7677452Group_concat:group_concat(distinct name) group_concat(name separator ‘;‘) // 默认是,group_concat(name order by name desc)SELECT * from Shelvesopbusinessrel;SELECT s0.id,s0.listnum,s0.warehouseid,s0.businessquantity,s0.productquantity,s0.printdate,group_concat (Rel.businessnum)From Shelvesoplist S0Left Join Shelvesopbusinessrel relOn s0.id = Rel.shelvesoplistidGROUP by S0.listnumORDER by S0.id DESC;

'ENDWHERE ID in (All-in-a- Here, a MySQL statement has been completed to update multiple records.But to use in the business, you need to combine the service-side language, here in PHP, for example, constructs this MySQL statement: The code is as follows:$display _order = Array (1 = 4,2 = 1,3 = 2,4 = 3,5 = 9,6 = 5,7 =

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 End, title = case ID When 1 THEN ' New Title

? MySQL does not provide a straightforward way to implement batch updates, but it can be accomplished with a little bit of skill. code as follows: UPDATE mytable SET myfield = case ID When 1 Then ' value ' When 2 Then ' value ' When 3 Then ' value ' END WHERE ID in (All-in-a- This is a small trick to implement a batch update. As an example: cod

evaluation ', MAX (if (course= ' language ', familyevaluate,null)) As ' family evaluation ', MAX (if (course= ' language ', societyevaluate,null)) as ' social assessment ', max (if (course= ' English ', score,0)) as ' English ', Max (if ( Course= ' English ', bossevaluate,null) as ' principal evaluation ', MAX (if (course= ' English ', familyevaluate,null)) as ' family Assessment ', Max (if (course= ' English ', Societyevaluate,null) as ' social assessment ' from ds_wjytest2.student Group by na

Batch update The mysql update statement is simple. to update a field of a piece of data, write as follows: Copy codeThe Code is as follows:UPDATE mytable SET myfield = 'value' WHERE other_field = 'other _ value '; If the same field is updated to the same value, mysql is also

Perform updates on a single table nothing more to say than to update table_name set col1 = Xx,col2 = yy where col = zz, which is mainly the setting of the Where condition. Sometimes updating a table may involve more than one datasheet, for example: The code is as follows Copy Code Update Table_1 Set score = score + 5 where UID in (select UID from table_2 where sid = 10);In fact,

Mysql update modifies multiple data entries and mysql updatesGenerally, the following SQL statement is used to update the field value:Copy codeThe Code is as follows:UPDATE mytable SET myfield = 'value' WHERE other_field = 'other _ value ';However, what if you want to

And MySQL in contrast to see: http://blog.csdn.net/rainyspring4540/article/details/50231435 This is the oracle10g environment. The database structure is as follows: If I want to show the same name on the same line, there are 2 basic shows: First presentation (displayed on different columns of the same row) Its SQL is as follows: Select Name, max (decode (type, ' math ', score,0) as math, max (de

Batch update names separated by commas (,) (multiple IDs separated by commas (,) in a department are converted into names separated by commas (,) (mysql) and comma (,) mysqlUpdate dept B, (select group_concat (t. deptId), group_concat (d. deptName separator '/') as dName, t. id, t. deptName from (select substring_index (. deptId, ',', B. help_topic_id + 1), ',',-

and control columns are cyclically displayed in the same field, the principle is to read the first loop by using Limit, and then add the number of records read in the first loop to the number of columns displayed in each row. The following code is directly attached: Code for the first loop: ”/> Loop code later: ”/> Of course, there is a more direct method, that is, the first loop of