mysql table structure query

MySQL Query performance optimizationThe optimization of MySQL query performance involves many aspects, including library table structure, establishing reasonable index and reasonable query. The library table structure includes how to design

In order to better optimize MySQL in high concurrency, it is necessary to understand the locking table mechanism when MySQL query is updated.I. OverviewMySQL has three levels of Lock: page level, table level, row level.MyISAM and MemoryStorageThe

High Performance MySQL Reading Notes-query performance optimization, high performance mysql For high-performance database operations, it is not enough to design the optimal database table structure and build the best index. You also need to design

MySQL data import and export:Import:Save the contents of the system file to the table in the databaseBasic format for importing data:mysql> load Data infile "file name" into table name fields terminated by ' delimiter ' lines terminated by ' \ n

The main contents of this chapter: First, foreign key Second, table connection Third, sub-query Iv. Index first, foreign key: 1. What is a foreign key 2. Foreign KEY syntax 3, FOREIGN key conditions 4.

MySQL常用指令，java，php程序员，数据库工程师必备。程序员小冰常用资料整理MySQL common commands (for reference)The most common display commands are:1. Display the list of databases.show databases;2. Display the data table in the library:Use MySQL;Show tables;3, display the

For high-performance database operation, it is not enough to design the optimal library table structure, and to establish the best index, but also need reasonable design query. If the query is poorly written, high performance cannot be achieved even

1. View Data Table Structure 1) view the basic table structure statement DESCRIBE syntax: DESCRIBE table name; example: mysqlDESCRIBEproduct; + ---------------- + ------------ + ------ + ----- + --------- + ---------------- + | Field 1. view the

mysql--Multi-Table queryConnection query:Cross Connect:Result: Back basics The number of data rows in the first table, multiplied by the compound query criteria in the second table.Syntax format: Select query content from table 1 cross join table

ALTER TABLE Syntax ALTER [IGNORE] TABLE tbl_name alter_spec [, Alter_spec ...] Alter_specification:ADD [COLUMN] create_definition [i | After column_name]or ADD [COLUMN] (create_definition, create_definition,...)or ADD INDEX [index_name] (Index_col_