mysql update multiple columns

Mysql "on duplicate key update" SyntaxIf the on duplicate key update is specified at the end of the INSERT statement and the DUPLICATE value appears in a UNIQUE index or primary key after the row is inserted, UPDATE is executed ON the row with the DUPLICATE value; if the unique value column is not duplicate, a new row

From http://blog.csdn.net/iwtbavcp/article/details/6455704 It's really a cold post that solves my big problem. MySQL update sdata truncation: Truncated incorrect double value :?? S Recently I used JSP and MySQL to create something and encountered a problem: When the update statement is used, data truncation: Trun

a subquery." In this case, it is easy to solve the problem, but sometimes you have to update the target with a query clause. Fortunately, we have a way. Solutions Since MySQL implements nested queries within the FROM clause through a temporary table, the nested query is loaded into another nested query, so that the FROM clause query and save are done in a temporary form, and then indirectly in the perim

. Fortunately, MySQL takes this into account, providing the syntax that, when an insert is made insert … on duplicate key update , if the insert data causes a unique index (including the primary key index) to conflict, that is, if the unique value is duplicated, the insert operation is not performed and the subsequent update operation is performed.For exampl

Note: This document has two MySQL instances, multiple instance methods and so on Linux operating system: centOS6.3 64bit (Installation of the system default development package)Database one:MySQL version: mysql-5.0.56port:3306System catalog:/usr/local/mysql3306Database two:MySQL version: mysql-5.1.72port:3307System ca

Low_priority, Low priorityUPDATE [low_priority] tbl_name SET col_name1=expr1,col_name2=expr2,... MySQL update with low_priority let update do not lock the table MySQL allows you to change the precedence of statement scheduling, which enables queries from multiple clients t

For example, if column a is defined as unique and the value is 1, the following statements have the same effect, that is, once the entry and exit records contain a = 1, directly update c = c + 1 without executing c = 3.Copy codeThe Code is as follows:Insert into table (a, B, c) values (1, 2, 3) on duplicate keyUpdate c = c + 1; 1 update table set c = c + 1 where a = 1; It is also worth mentioning that this

Let's take a look at the update syntax first. UPDATE The update feature is updating the data in the table. This syntax is similar to the second use of insert. You must provide a table name and a set expression, where you can add a where to limit the updated record range. The code is as follows Copy Code

Configure multiple mysql versions in centos Environment Scenario: You need to upgrade the original version of MySQL to a later version of mysql. Solution: to reduce the impact of mysql upgrades on the business, you can configure a later version of

Update: Tanku Updates Needless to say, the two are the same, mainly talking about the update of multiple tables Copy Code code as follows: Oracle> Oracle's multiple-table update requirements are more stringent, so sometimes it's not very good to write, we can t

Mysql UPDATE problem UPDATE nbsp; cg_disease_department nbsp; AS nbsp; a nbsp; SET nbsp;. department_id nbsp ;= nbsp; nbsp; SELECT nbsp; department_id nbsp; FROM mysql update problems UPDATE cg_disease_department AS a SET

Mysql update multi-Table instances Let's take a look at the following example: Instance 1: Update tab1 set tab1. item size = (select tab2. item size from tab2 where tab2. item color = tab1. item color) where tabl1. item color in (select tab2. item color from tab2) Continue with the following example: UPDATE CMS_Documen

Label:first, the data table structure CREATE TABLE ' Jx_attach ' ( ' attach_id ' int (one) not null auto_increment, ' feed_id ' int (one) DEFAULT NULL, ' att Ach_name ' varchar (255) NOT NULL, ' cycore_file_id ' varchar (255) DEFAULT null, ' attach_size ' bigint (a) NOT null D Efault ' 0 ', ' complete ' smallint (6) Not NULL DEFAULT ' 0 ', PRIMARY key (' attach_id '), key ' JX_TREND_ATTACH_FK ' (' feed_id ') USING BTREE ) engine=innodb auto_increment=394160 DEFAULT Charset=utf8

MySQL databaseHow to ImplementCross-Table updateAndData MergingWhat about it? This article uses an example to introduce how to achieve cross-Table update and data merging. The example is as follows: a lot of resource data must be appended to a table in the MYSQL database because of the large data volume, therefore, the table is divided into several parts based on

Insert or update in MySQL (similar to Oracle's merge statement), oraclemerge If the record does not exist in MySQL, insert the statement. If the record does not exist, update the statement. You can use the following statement: Update a field: Insert into tbl (columnA, col

INSERT ... On DUPLICATE KEY UPDATE statementMySQL has been supporting insert since version 4.1 ... On DUPLICATE KEY UPDATE syntax, it is necessary to execute 3 SQL statements (select,insert,update), reduced to 1 statements to complete.INSERT ... On DUPLICATE key Update, when an inserted record raises a primary key conf