MySQL

In linux enterprise 5, mysql 5.6 is installed with cmake after mysql 5.5. cmake is an essential tool for installing mysql 5.5. Install cmake as follows. Download the source code installation package from the cmake website [root @ localhost ~] # Wget

The solution to installation failure of MySQL5.6 management account in linux is nothing, just to record the time I spent this afternoon for no reason. To avoid wasting the same time next time, I should record the problems and solutions I encountered

This article introduces a very practical function replace in SQL. This function can replace the character you specified. The following describes how to use the update statement. Mysql replace string function can replace some strings of a field with

This article introduces two common problems in mysql usage: to change the mysql character set, we generally use phpmysqdmin or in my. you can refer to this article to solve Chinese Garbled text problems. MySQL Character Set: cp1252 West European

MySQL string case-sensitivity conversion requires the MySQL string case-sensitivity conversion function. MySQL string case-sensitivity conversion functions include lower (), uppper (), lcase (), and ucase ():   The Code is as follows:

To obtain the first record after grouping by group, we need to combine order by. Originally, we used group by to retrieve all groups, then, we can use order by to sort the data in the group by desc and retrieve the first shard. First, let's look at

The similarities between the three commands: truncate and delete without the where clause, and drop will delete the data in the table. The difference is that truncate will clear the table data table and set the id to start from 1, delete: only

The total value of an expression returned by the SUM function. This function is also very useful. Let's take a look at the detailed usage of this function. The syntax of the SUM function is: The Code is as follows: Copy code

In MySQL, Replace INTO plays a very powerful role. Many friends are useless, but its function is better than update insert. The reason is not as follows. The author of a plug-in day DST asked me about the difference between Replace INTO and insert

We often forget the mysql root password, so how can we find it? re-installation is too difficult to configure, next, let me introduce two methods to retrieve passwords in linux and mysql. Like * UNIX version: The following is an incorrect

Many of our friends prefer to use third-party tools to import and export data. In fact, our mysql comes with this tool, as long as it can be operated in command mode, of course, it can also be used in php. The method is the same as below. If you

How to handle forgetting the mysql password (linux, windows) This section describes how to handle the mysql password. It mainly describes how to retrieve the password in different operating systems, such as linux and windows. How to deal with

A typical page-level engine is BDB. A typical table-level engine is MyISAM, MEMORY, and ISAM, which was a long time ago. A typical line-level engine is INNODB. A typical page-level engine is BDB.A typical table-level engine is MyISAM, MEMORY, and

The order by statement is used to sort the result set based on the specified column. BY default, the order by statement sorts records in ascending ORDER. If you want to sort records in descending order, you can use the DESC keyword. Instance

SELECT statements are used to SELECT data from a table. Results are stored in a result table (called a result set ). SQL SELECT syntaxSELECT column name FROM Table Name and: SELECT * FROM table name Note: SQL statements are case-insensitive. SELECT

String truncation common functions in mysql tutorial Mysql string truncation function:Left () returns the leftmost len character of the str string,Right () returns the rightmost len characters of the str string,Substring () returns a substring from

Replace syntaxReplace [low_priority | delayed] [into] tbl_name [(col_name,...)] values ({expr | default },...), (...),... or: Replace [low_priority | delayed] [into] tbl_name set col_name = {expr | default},... or: Replace [low_priority | delayed]

Single Table Syntax: delete [low_priority] [quick] [ignore] from tbl_name[Where where_definition][Order by...][Limit row_count] Delete all rowsYou can delete all rows without deleting a table. This means that the table structure, attributes, and

In fact, it is to tell the mysql tutorial interpreter whether the command has ended and whether mysql can be executed.By default, delimiter is a semicolon ;. In the command line client, if a command line ends with a semicolon,After you press enter,

For large tables in the database, statistical queries are usually slow, and you need to consider whether the query will affect online applications, in this case, we can use an intermediate table to increase the query statistics speed. Next we will