MySQL and PostgreSQL database learning notes

MySQL cannot support the data version from the most basic data engine to the process structure. Causes its function to block "concurrency", does not support the most basic transaction, InnoDB does not reach the basic transaction requirements, any write data, causes the entire table to lock. At best, a toy, or a key->value data store, is no different than a database (RDBMS) MySQL cannot support any OLTP or OLAP. Can only be used as the basic data store for CRUD, published to Static. Currently, all MySQL applications can only reach this level. Oracle, the industry benchmark in all aspects of the database, has been imitated and never surpassed. But the price is expensive.

A, MySQL data type

Character: Varchar,char,text

Numbers: Smallint,int,bigint

Date: Date,datetime,timestamp

B, paging query

Limit queries the middle data in the database; offset offsets

http://www.csdn.net/article/1970-01-01/308040

Pg does not have a variety of MySQL pits

Date functions in MySQL

Select 1 Day);

Date function in PG

Select     ' 2016-04-12 ' - integer ' 1 ';

MySQL and PostgreSQL database learning notes