MySQL

In fact, there is a difference between the two. last_insert_id () can return the ID of the bigint value. However, mysql_insert_id returns Int. If you The ID of is unsigned Int or bigint. The returned result may be incorrect. Instead of

If the fields of the two tables are consistent and you want to insert all the data, you can use this method: Code: CopyCodeThe Code is as follows: insert into target table select * from source table; For example, to insert the articles table to

1. The Concat function is often used to convert int to varchar. For example, the Concat (8, '0') string '80' is obtained' 2. Convert varchar into an int string of the varchar type using cast (A as signed). Summary: type conversion is similar to

The larger the physical memory, the larger the setting. The default value is 2402, and the value is adjusted.Innodb_additional_mem_pool_size = 4 m; default value: 2 mInnodb_flush_log_at_trx_commit = 1(If it is set to 0, innodb_log_buffer_size is

MySQL allows you to specify multiple statements for execution in a single query string by specifying parameters for the link: CopyCode The Code is as follows: // set when linking Mysql_real_connect (..., client_multi_statements ); // Or // Specify

For example, if the existing string "[] aseabcd [12345] ddxabcdsx []" is to be intercepted, the content between "ABCD [" and "first"] "after" ABCD ["" 12345 ", of course, the content length is not fixed, it can be "123456" or other strings.When he

CopyCode The Code is as follows: delimiter $ CreateFunction 't_gir'. 'func _ rand_string '(f_num tinyint unsigned, f_type tinyint unsigned)Returns varchar (32)Begin-- Translate the number to letter.-- No 1 stands for string only.-- No 2 stands

MySQL connector/net5.0: Http://dev.mysql.com/get/Downloads/Connector-Net/mysql-connector-net-5.0.6.zip/from/pick After installation, Click properties, then find the target, click a directory to the upper level, and find binaries \. NET 2.0, and then

Example: CopyCodeThe Code is as follows: Generally, lazy is set to true instead of false, because if it is set to false, the corresponding sub-table will also be queried while querying the master table, added a lot

Cause: Microsoft released the TCP/IP update Patch (kb967723) on September 23, September 9. If the server enables automatic updates or the software for Automatic Updates is downloaded and updated, this problem occurs. Some may ask why the patch on

G, the solution is as follows: In the/var/lib/MySQL directory, delete ibdata1, ib_logfile1, and ib_logfile0, and restart MySQL to recreate the above files: Mysqladmin-uroot-P Shutdown Sudo mysqld_safe & Done! Below are otherArticle. For more

Mysql> select something from tbl_name Where to_days (now ()-to_days (date_col) Dayofweek (date)Returns the week index of date (1 = Sunday, 2 = Monday,... 7 = Saturday ). The index value complies with ODBC standards.Mysql> select dayofweek ('2017-

Relatively speaking, it is straightforward to load data into the database. However, there are also policies to improve the efficiency of data loading operations. The basic principles are as follows: Batch loading is faster than single-row loading,

The table lists various numeric types, their permitted ranges, and occupied memory space. Type Size Range (Signed) Range (unsigned) Purpose TINYINT 1 byte (-128,127) (0,255) Small integer SMALLINT

After obtaining the requirement, I found that the MYSQL databases of both websites cannot be remotely accessed (security first ). This reminds me of the CSV files used for batch data input. Therefore Try to import and export data using CSV. The

Mysql 5.1 supports triggers and UDF features. If libmemcache and Memcached Functions for MySQL are used together, memcache can be automatically updated. Record the installation and testing steps. Installation Steps Install memcached. This step is

MySQL Escape Character "\" Mfc_basic MySQL recognizes the following escape characters: \ 0 An ASCII 0 (NUL) character. \ N A newline character. \ T A positioning character. Separator \ R A carriage return. \ B A return character. \' A single

Directory 1. Character Set Selection 1 2. Primary Key 1 3. Foreign key 2 4. index 2 4.1 The following conditions are suitable for creating an index 2 4.2. Index 3 is not suitable in the following cases 4.3. Joint index 3 4.4. Index length 4 5.

/Usr/bin: mysql installation directory Create a backup Folder: Mkdir mysql_data_bak Create a script file: Touch autobackupmysql. sh Open a file Vi autobackupmysql. sh Add the following content to the script: Filename = 'date + % Y % m % d' /

MySQL string functionsFor operations on the string position, the first position is marked as 1. ASCII (str) Returns the ASCII code value of the leftmost character of the str string. If str is a Null String, 0 is returned. If 'str' is NULL, return