mysql pivot table

, ' user6 ', ' 123 ', ' [emailprotected] '); INSERT into ' user ' (' id ', ' username ', ' pwd ', ' email ') VALUES (7, ' user7 ', ' 123 ', ' [emailprotected] '); INSERT into ' user ' (' username ', ' pwd ', ' email ') VALUES (' User8 ', ' 123 ', ' [emailprotected] '); So the ID incredibly is 0 this is a bit strange, if not solve, each time inserting new data, to add last_id .... (PHP code to change) Pros: Extensibility is good, and PHP code almost doesn't have to be changed, but it's somet

When creating a temporary table, you can use the temporary keyword. For example: 　　create temporary table tmp_table(name varchar(10) not null,passwd char(6) not null) The temporary table is only visible to the current connection. When the connection is closed, it is automatically dropped. This means that you can use the same temporary

previously used, unless manually modified orInnodb_file_per_table=1 to use exclusive tablespaceInnodb_file_per_table=0 to use shared table spacesModify the data storage location for exclusive empty table spacesInnodb_data_home_dir = "C:\mysql\data\"Innodb_log_group_home_dir = "C:\mysql\data\"Innodb_data_file_path=ibda

1=2 6. You can copy table 1 to table 2 SELECT * into table 2 from table 1 7, show create table old tables; This lists the creation commands for the old table. We just need to copy the command, change the name of the

In the temporary mysql table, xxx is full. You only need to modify the tmp_table_size and max_heap_table_size parameters in my. ini. Tmp_table_size if the temporary table in the memory exceeds this value, MySQL automatically converts it to the MyISAM table on the hard disk.

Create a tableData type int (shaping, Integer) not Null,char (character) tinyint (smallest shaping) varchar (variable-length character type)CREATE TABLE Xiaohu (ID Int (4) is not NULL,Name Char (a) is not NULL,Age tinyint (2) is not null default ' 0 ', (Can not be empty, but can give 0)Dept varchar (+) default null (can be NULL)Such asMysql> CREATE TABLE Student (-ID Int (4) NOT NULL,, name char (a) is not

This article will show you what the derived table (Derived tables) is in MySQL. and MySQL optimized for it.BackgroundLike the next table:Mysql> descCity ;+------------+-------------+------+-----+---------+-------+|Field|Type| Null | Key | Default |Extra|+------------+-------------+------+-----+---------+-------+|Country| varchar( +)|YES| | NULL | ||P

Method One: Use SQL statement to modify MySQL database table prefix name The first thing we think of is to use SQL query statements to modify, this method is also very convenient, just enter the phpMyAdmin, in the Run SQL query box to enter the following name on it. ALTER table The original table name RENAME to new

A beginner's database, a record of what you've learned. I used the MySQL database to manage with MySQL Workbench. Here's a quick introduction to using MySQL Workbench to build a database, create a new table, and add data to a table.Click on the "Plus" icon to create a new connection,For example, first enter the databas

the Pt-table-checksum verification function, which can be repaired on one side or based on the pt-table-checksum calculation results. Checksum (master server run) Pt-table-checksum--nocheck-binlog-format--nocheck-plan--nocheck-replication-filters--replicate=pt.checksums-- Set-vars innodb_lock_wait_timeout=120--databases newtable-u ' checksums '-

When we build a table, some fields are always used. That is, each table will have these fields.I have a little time with MySQL, today (2016-02-27 21:53:38) when using Mysql-front to build a table, I feel a little bit uncomfortable.is the field in some tables, and basically e

Tags: LTE modify change div Add char class weight font Alter TableTest rename test1;--Modify Table name Alter TableTestAdd columnNamevarchar(Ten);--Adding table Columns Alter TableTestDrop columnName--Delete a table column Alter TableTest Modify AddressChar(Ten)--modifying table column types ||Alter TableTest Chan

name becomes No. Columns with non-null constraints must be passed when the value is passed in. Unique constraint: 　　Make sure that the values in the field are unique:unique key As with not NULL, it can be built at the time of the table: 　　 To delete a unique constraint: 　　 Add a UNIQUE constraint: Now add a column ' name ' to the TB, let's add a union unique after: 　　 At this point, the federated unique key name is ID, so delete just need to write:

MySQL instance using ALTER TABLE command to modify the table structure The MySQL ALTER TABLE statement can modify the basic structure of the table, such as adding fields, deleting fields, adding primary keys, adding indexes, modi

9.9 Table Operation9.9.1 building a library with the default character setIn the default format, specify the character set to build the library[emailprotected] 07:0205->create database wwn;Query OK, 1 row affected (0.00 sec)[emailprotected] 07:0339->SHOW CREATE DATABASE wwn\G;*************************** 1. row *************************** Database: wwnCreate Database: CREATE DATABASE `wwn` /*!40100 DEFAULT CHARACTER SET latin1 */row in set (0.00 sec)

joint index of the two, the insertion will be slow, the index file will become larger ). This is basically the case. To avoid the misunderstanding that all tables must have a unique incrementing key. I want some help. Clustered index:MySQL InnoDB will certainly create a clustered index to store the actual data rows and related key values in one partition. This also determines that a table can have only one clustered index, that is,

=1421668046873, value=\xE6\xB1 \x9f\xe8\x8b\x8f\xe5\x8d\x97\xe4\xba\xac 2_\xe9\xbb\x84\xe6\x98\x93\xe6\x9f\x90 Column=stuInfo:school, timestamp= 1421668046873, Value=\xe5\x8d\x97\xe4\xba\xac\xe5\xa4\xa7\xe5\xad\xa6 3_\xe6\x9d\x8e\xe5\x9b\x9b column= Stuinfo:address, timestamp=1421668051471, value=\xe6\xb1\x9f\xe8\x8b\x8f\xe8\x8b\x8f\xe5\xb7\x9e 3_\xE6\x9D\x8E\ xe5\x9b\x9b Column=stuinfo:school, Timestamp=1421668051471, Value=\xe8\x8b\x8f\xe5\xb7\x9e\xe5\xa4\xa7\xe5\xad\xa6 4_\xe7\x8e\x8b\xe6\xb5

MySQL master-master replication, modifying table structure bitsCN.com online MySQL master-master replication, modifying the table structure online I always thought that the dual-master architecture could solve the mysql table on

Mysql supports cross-table delete multi-table record bitsCN.com a few days ago, I wrote a summary of Mysql cross-table update. today we will look at cross-table deletion. After Mysql4.0, mysql