MySQL

Export files using PhpexcelFirst look at the above article, write method, just the middle of the database operation, followed by the Excel browser output.Database code (Database configuration file self-completed)conn=mysql_connect ($ config[' host ',

MySQL default encoding is Latin.My MySQL version is 5.6. There is no My.ini under the installation path, but there is my-default.ini. In fact, MySQL does not have a configuration file can also be started, but in order to set the encoding, you need

1. Description of false narrativeCom.mysql.jdbc.exception:jdbc4. Mysqlsyntaxerrorexception:unknown column ' Man ' in ' Field list '2. Cause of Errorfields in database tables: Sno sname Sage SsexWhen inserting data: Sno sname Sage ManOriginally

SQL optimization1 MySQL optimization directionIO total elapsed Time index setting2 SQL and Index optimizationHow to analyzeTable type Possible_keys Key_len ref rowsExplain returns the meaning of each columnUsing Filesort3 count () and Max ()File IO,

1. Add so few lines in/etc/my.cnfig [Mysql]default-character-set=utf8 [Mysqld]character-set-server=utf8 [Client]default-character-set=utf8 In general, add the above three can be, we can use such a command to view mysql> show variables like  '

First initialize a tableDROP TABLE IF EXISTS' lq_wx_sign ';CREATE TABLE' lq_wx_sign ' (' ID ')int(2) unsigned not NULLAuto_increment COMMENT'primary Key ID', ' name 'varchar( -) not NULLCOMMENT'User name', ' open_id 'varchar( -) not NULL DEFAULT

MYSQL Stored Procedure Learning notesMySQL 5.0 has finally started to support stored procedures, which can greatly improve the processing speed of the database, but also improve the flexibility of database programming. Advantages of stored

For some time without writing and forgetting./*Cancel foreign KEY constraint*/SETForeign_key_checks=0;/*create C1 table primary key ID field name*/DROP TABLE IF EXISTS' C1 ';CREATE TABLE' C1 ' (' ID ')int( One) not NULLauto_increment, ' name

A new MySQL database table was created yesterday, and when inserting Chinese characters into Java, it was found that the insertion result in the database was garbled. The actual character set does not meet the problem.There are a number of solutions

Recently in the last interface Test training course, need to use MySQL, downloaded from the official website x64 Compression package version, after the decompression according to Baidu experience in the instructions, step-by-step use, started normal,

Integer type:tinyint, smallint, mediumint, int, bigint respectively use 8, 16, 24, 32, 64-bit storage space, in the case of ensuring that the storage value is sufficient, select the smallest data typeReal type (when a fractional part is

MySQL error code1005: Failed to create table1006: Failed to create database1007: Database already exists, database creation failed1008: Database does not exist, delete database failed1009: Unable to delete database file causes database failure to be

SELECT Group_concat (Ut.id_card ORDER by Ut.id_card DESC SEPARATOR ', ') from ' Edu_user_train ' ut where ut.id in (614,615 ) Output: 500231199108181861,371324198450304515 usage Scenario: Returns a pure numeric mate in query example: SELECT u.name

MySQL database.Sometimes we need to sort the data of the query and display the ordinal, then we can use the following SQL statement to add an ordinal field to the data of the query result, the ordinal field will not be added to the original table,

It is not recommended to install Mysql-python with PIP because this version of mysql-python1.2.5 is automatically selected, but this version does not support Windows 32-bit systems.1. First install VS2008, because to rely on VC9.0 compile

If the ID is a primary key or has an index, you can find it directly:Method One:Query the SQL statement for the previous record (if you have additional query criteria, remember to add other_conditions to avoid unnecessary errors):Select * from

Many articles on the web say that if you encounterMySQL 1364 Error Tip: #1364-field "" doesn ' t have a default valueDescription you have configured "Strict_trans_tables"However, you may find that modifying the MY.CNF (under Windows for My.ini)

Linux Mysql Source package installation Install the Make editorMake compiler: http://www.gnu.org/software/make/./configureMakeMake install Installing Bisonbison:http://www.gnu.org/software/bison/ Installing

Mysql1. Materialized views are not supported.2. Bitmap indexing is not supported.3, parallel query is not supported.4. Hash associations are not supported, and all MySQL associations are nested loop associations. However, it can be achieved by

Service mysqld stop//stop MySQL ServicesCp-rf/var/lib/mysql/home/data//Copy the default MySQL database directoryChown-r mysql:mysql/home/data//Give new directory authorizationModify the my.cnf, to make sure that you have no problem, you can comment