mysql update multiple columns

This article describes how to sort and solve the problem by multiple fields in MySQL. it is very practical. if you need it, you can refer to it. To create a project, you need to filter out products in the product list so that they are listed at the end of the list, but all products are sorted by the update time. After studying the database structure of the sys

Tags: using SP html c htm sql MySQL PHP bsIn MySQL, use the RegExp keyword to match the query regular expression, which has the following basic form:Field name REGEXP ' Match method 'Pattern character meaning Use example ^ Match start SELECT ' books ' from ' Tb_name ' WHERE ' books ' REGEXP ' ^php ';$ match End SELECT ' books ' from ' Tb_name ' WHERE ' books ' REGEXP ' php$ ';. Match any one of the ch

Tags: picture emptying abi ISS mysql ALTER DATABASE configuration SQL statement outWork needs, use of notes. The article is very long, pour a cup of tea slowly look.There are many application scenarios of database, such as database synchronization , a master multi -Slave, multi- master and multi-slave , Multi-master one from , etc. the following records the configuration and testing of multiple master-one

qualificationReturns the row specified in the table on the left, regardless of whether there is a match in the right table.Right outer join: TBNAME1TBNAME2 on qualification returns the row specified in the table on the right, regardless of whether there is a match in the left table.Fully connected: TBNAME1 full join TBNAME2 on qualificationIn two tables, the corresponding row is returned as long as there is a match.Self-Connection: Connect yourself to yourself and implement it through as alias.

Mysql cross-Table update assumes that we have two tables. One Table stores Product information for the Product table, with the Product Price column Price. The other table is the ProductPrice table, update the Price field in the ProductPrice table to 80% of the Price field in the Price table. In Mysql, we have several w

Today make a judgment insert used in MySQL on DUPLICATE KEY UPDATE, now Mark below!You can choose on DUPLICATE KEY Update if you want to insert the data and update the data if you do not have the data in the database.The on DUPLICATE key update can perform an

at a time INSERT INTO table_name (column_list) Values (Value_list1), (Value_lsit2), ..., (VALUE_LSITN); More efficient INSERT statements for multiple rows of records Inserting query results into a table Insert can also insert the results of a SELECT statement query into a table Example: Insert into table_name1 (COLUMN_LSIT1) Select (Column_list2) from table_name2 where (condition); The number of fields in the Column1 and the data type of the field mu

When MySQL creates multiple instances, it actually points the data file, sock, and port to different files and ports. MySQL installation process see http://blog.csdn.net/tangpengtao/article/details/6650424 Create a 3307 data directory first [Root @ localhost mysql-5.5.15] # mkdir-P/usr/local/mysql3307[Root @ localhost

. However, it is not realistic if each SQL statement is a transaction. As a result, some businesses themselves require multiple SQL statements to form a transaction (such as the operation of multiple tables for remittances); and secondly, each SQL requires a commit, and if innodb_flush_log_at_trx_commit=1 in MySQL, it causes Redo log refreshes too frequently and

Digital phpupdate Insertion The combination of PHP and MySQL, for the operation of the number is completely correct, the database table is the property of varchar, the database is also set UTF8, but the problem should not be here, not only Chinese characters do not, the English alphabet is not, as long as 6 columns in a row of non-digital words, the update w

system notifies A that the ticket is successfully snatched. Then B also changes this record to his own, so the ticket for A becomes invalid at this time. Here we will consider using the lock mechanism. If A reads this record and adds A write lock to it, then others will no longer be able to read the lock and will not modify it multiple times. Lab resultsI tried locking for update and found some problems.1.

MySQL database update subquery For example: UPDATE test. tb_vobile aset a. name = '000000' WHEREa. id = (select max (id) id from test. tb_vobile) Error: [SQL] UPDATE test. tb_vobile aset. name = '000000' WHEREa. id = (select max (id) id from test. tb_vobile) [Err] 1093-You can't specify target table 'A' for

adapter = new OleDbDataAdapter (cmd ); DataSet ds = new DataSet (); Adapter. Fill (ds ); Con. Close ();} My Excel table only has one County table, but two tables are returned for query: Country and Country $ Print_Titles. When using the SQL statement: select * from ["+ sheetName +"] "; when reading table data, it can be normally read from Country, while Country $ Print_Titles throws an exception when trying to read the table data. Update the read d

and join the startup serviceAt present, the operation is not successful, the main problem is that despite the adjustment of my.cnf, but the point to the MySQL file is still inaccurate, resulting in id_logfile generation will be problematic. Theoretically it should be possible to read MY.CNF there is a cache update that requires a new update my.cnf under Copy to/

Today, I used MySQL's ON DUPLICATE KEY UPDATE to determine whether to insert data. Now Mark the following! If you want to insert or UPDATE data without data in the database, you can choose on duplicate key update. On duplicate key update can be used to UPDATE the old row whe

id=2", ("Mypython")) 1L >>> Cur.execute ("SELECT * from Users where id=2") 1L >>> cur.fetchone () (2L, U ' Mypython ', U ' 123456 ', As seen from the operation, the user name of the second article in the database has been modified to Mypython, with the UPDATE statement.However, to really implement updates in the database, you also run:>>> Conn.commit ()This is the end of the big deal.Python operation MySQL