MySQL

Modern applications Program Many languages are supported. Therefore, if MySQL is used in the database, utf8 encoding is generally recommended to store multilingual data. Another reason is that most development languages such as. NET and Java

MyISAM is the default storage engine in MySQL. Generally, not many people care about this. It is a tricky thing to decide what kind of storage engine to use, but let's take a look at it.ArticleOnly MyISAM and InnoDB are considered, because these two

Alter table structure in MySQL Project instance:Alter table testresult add xinlindoc longblob;Alter table testresult add xinlindocname varchar (50 );Other instances:Create Table T1 (a integer, B char (10); // The created table T1 starts. Alter

This PHP does not have a direct function to determine whether the database field is empty. However, we can use the mysql_fetch_array () function to return Value.For example.Method 1:$ SQL = "select * Form ABC"$ Result = mysql_query ($ SQL );$ ROW =

1. MySQL Common commands Create Database Name; Create a database Use databasename; select database Drop database name directly deletes the database, no reminder Show tables; displays tables Describe tablename; Detailed description of the table Add

Create definer = 'root' @ '%' function 'SP _ cn' (n_lowermoney decimal (200) returns varchar () charset utf8Begin Declare v_lowerstr varchar (200 ); Declare v_upperpart varchar (200 ); Declare v_upperstr varchar (200 ); Declare I _ I int;   Set

Let's talk nonsense.Body Today, someone needs to export an excel table from the database. This person is a non-technical engineer and needs: Export the voting data of contestants from the 19th to the 25th in excel format. OK. You can see this

Problem: java. SQL. SQLException: Data truncation: Data too long for column 'content' at row 1 Query Some online solutions for this problem: Solution 1: From: http://www.blogjava.net/zoninge/archive/2009/04/15/265663.htmlThank you, blogger!When

Document directory 7.2.2 estimate query performance 7.2.2 estimate query performance     In most cases, you can estimate the query performance by counting the number of disk searches. For small tables, you usually only need to search a disk once

When using mysql, you sometimes need to query records with unique fields. Although mysql provides the keyword distinct to filter out redundant duplicate records, only one record is retained, but it is often used to return the number of records that

1. clone a table You can use Create Table... like statement to clone the table structure; Use insert into... select Statement to clone part or all of the table data.  2. Temporary table Need a table created for temporary use only and automatically

MySQL always crashes First, you should try to find out whether the problem mysqld daemon is dead or whether your problem is related to your customer. You can use mysqladmin version to check how long your mysqld server has been running normally. If

1. Multi-Table connection type 1. Cartesian Product (cross join)In MySQL, you can think of cross join or omit CROSS as JOIN, or use ',' for example: SELECT * FROM table1 CROSS JOIN table2 SELECT * FROM table1 JOIN table2 SELECT * FROM

OPTIMIZE [LOCAL | NO_WRITE_TO_BINLOG] TABLEtbl_name[,tbl_name] ... If you have deleted a majority of the tables, or if you have made many changes to the tables that contain variable-length rows (tables that contain varchar, blob, or text columns,

In the recent project, you need to copy several dump files (text format, 1 ~ 2 GB) records are imported into the MySQL database. Due to the large data volume (millions or tens of millions of records), there are insert records and update records, the

After the windows 7 system is installed, mysql 5.134 cannot be installed when the ROR environment is configured. The problem occurs in the last step. The specific error is as follows: Unload and reload. Simply remove all mysql items, including the

Http://www.sun.com/bigadmin/content/submitted/mysql_smf_tip.jspLogin ing MySQL to Use With Service Management Facility (SMF)   William Pool (Puddle), October 2005. The Solaris 10 OS uses the Service Management Facility (SMF) to handleservices.

Dim driverName, chsDriverName = "Driver = {mysql odbc 3.51 driver}; server = localhost; database = discuz; uid = root; pwd = ;"Set conn = server. createobject ("adodb. connection ")Conn. open driverName Set conns = Server. CreateObject ("ADODB.

Extended Apache module development most of the tutorials on the Internet are centered on the Perl language memory. The "Writing Apache Modules with Perl and C" by foreigners can be regarded as a classic, but it has always been developed for older

. The three files can be searched by Baidu. 1. install php 1) Create a New PHP folder on the D Drive and decompress php-5.2.0-win32.zip to D: \ PHP. 2) Find the PHP. ini-dist file in the D: \ php folder and copy it for backup. Rename the copied file