MySQL

Insert a data table in mysql. If the data contains '\', it may cause a syntax error. You don't need to explain this. You know, you need to write an escape function. At the beginning, you want to directly use the string replace, however, this method

When querying a database, we sometimes need to add the sequence, 1, 2, 3 ,...... N For example, after sorting a table field, we need to add a sequence to the Data. At this time, the sequence number is often not the auto-incrementing primary key id

  Fedora8 mysql startup error:   ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/lib/mysql. sock' (2)   1. Check/etc/rc. d/init. d/mysqld status to see if m y s q l has been started. Check whether the permission is

  Recently I encountered such a problem. The data retrieved from the database is clearly "", but the program always displays "2011-11-10" during running ". Later, after debugging, we found that JDBC connection and resultset are both East 8 (system

  After learning the lexical analysis and syntax analysis, I started my formal learning tour of Mysql source code. How many modules can we start ?! Fortunately, I found a module division from the internet. I will try to track the source code step by

MYSQL5.x works in 'strict mode' by default in windows. When the table creation statement contains the following:Description text default 'www .naozao.com 'statement, it will give you an error or warning informationBLOB/TEXT column 'description'

On percona performance conference 2009, several Yahoo engineers brought a "Efficient Pagination Using MySQL" report, which has many highlights. This article is a further extension based on the original article. First, let's take a look at the basic

1. IndexingIn addition to the ordered search mentioned above, the database can greatly improve the query efficiency by using various fast locating technologies. In particular, when the data volume is very large and the query involves multiple tables,

I encountered several cases where MySQL did not use the expected index. After reading some documents, I found that the impact of MySQL type conversion on index selection is not small. For example, there is a MySQL table: Create table 'indextest

Replace into is very similar to insert into. The only difference is that when replace into is used, the system first checks whether there is a record that is the same as the statement to replace into Based on the table's primary key, if yes, delete

The characteristic ACID of a transaction, that is, atomicity, consistency, isolation, and durability. Atomicity ensures that a transaction is a minimum unit and cannot be split internally. Consistency ensures that each operation thread in the

When operating the mysql database under CentOs, a series of problems are encountered: Java code 1. ERROR 1044 (42000) during local connection: Access denied for user ''@ 'localhost' to database 'mysql' 2. remote connection 1130-host... is not

When creating a new TABLE that year, you can add an ENGINE or TYPE option to the create table statement to tell MySQL what TYPE of TABLE you want to CREATE: create table t (I INT) ENGINE = INNODB; create table t (I INT) TYPE = MEMORY; to convert a

Some people asked about the MySQL uuid function. A brief introduction. UsageThe value is different for each execution. Generation rule 1st 2 3 is time-related. Www.2cto.comTime_low, time_mid, and time_high_and_version are converted into hexadecimal

MySQL 5.5 proxy user disguised USER analysis since MySQL 5.5 released the first version, a new record is added to the GRANT permission list: PROXY. Do not think this is the previous MySQL Proxy. In fact, this is used as a vest for users. Let's take

1. in a subquery condition, you can use the results of another query as part of the condition. For example, you can determine whether the column value is equal to the value in a query result set, A query that is part of a query condition is called a

The built-in functions in MySQL are used in the select statement and the update delete function in the where order by hacing clause. The field name can be used as a field. The value of the variable is the record of each row corresponding to the

Amazon RSD viewing slow_log amazon RSD does not provide SSH direct access to the db server. However, Amazon RDS Command Line Toolkit is provided, but it is not so convenient to adjust some system parameters of mysql. Here we mainly record the

MySQL common SQL optimization statements insert data in large batches. 1. For tables of the Myisam type, you can import a large amount of data quickly using the following methods. Alter table tblname disable keys; loading the dataALTER TABLE tblname

When installing mysql, the last step is always the last step after the configuration is submitted. The installation fails and the Process Manager shows that the program has no response, mysql Service Startup error 1067. I searched the online answer