Parsing Mysql's INFORMATION_SCHEMA database _mysql

The INFORMATION_SCHEMA database was created after version 5.0 of MySQL, a virtual database that does not physically exist.
The INFORMATION_SCHEMA database is similar to the "Data Dictionary", which provides access to database metadata in the form of data. such as database name or table name, column type, access rights (more granular access).

Among the important tables are:
schemata table
---schemata table provides information about all the databases in the current MySQL instance. Is the result of show databases this table.
Tables Table
---Tables provide information about the tables in the database (including views). Describes in detail which schema, table type, table engine, creation time, and so on. Is the result of the show tables from SchemaName.
Columns Table
---Columns table provides the column information in the table. Detailed description of all columns of a table and information about each column. Is the result of show columns from schemaname.tablename this table.
Statistics Table
---Statistics table provides information about table indexes. Is the result of the show's index from schemaname.tablename this table.
User_privileges table
---user_privileges (user Rights) table gives information about the full permissions. This information originates from the Mysql.user authorization table. Non-standard table.
Schema_privileges table
---schema_privileges (schema permissions) table gives information about schema (database) permissions. This information is from the MYSQL.DB authorization table. Non-standard table.
table_privileges Table
---table_privileges (table permissions) table gives information about table permissions. This information originates from the MYSQL.TABLES_PRIV authorization table. Non-standard table.
column_privileges Table
The---column_privileges (column permissions) table gives information about column permissions. This information originates from the MYSQL.COLUMNS_PRIV authorization table. Non-standard table.
character_sets Table
The---character_sets (character set) table provides information about the available character sets for MySQL instances. is the table CHARACTER set result set.
collations table
---collations table provides control information about each character set.
Collation_character_set_applicability table
---collation_character_set_applicability table indicates the character set that can be used for proofreading. These columns are equivalent to the first two display fields of show collation.
table_constraints Table
---table_constraints table describes the table in which constraints exist. And the constraint type of the table.
key_column_usage Table
---key_column_usage table describes the key columns with constraints.
Routines Table
---Routines table provides information about storing subroutines (stored programs and functions). At this point, the routines table does not contain a custom function (UDF). A column named "Mysql.proc name" indicates the corresponding INFORMATION_SCHEMA. The Mysql.proc table column of the routines table.
Views table
---View table gives information about views in the database. You will not be able to view the view information if you need to have show views permissions.
triggers table
The---Triggers table provides information about the triggering program. You must have super permission to view the table.
In addition, new table additions will be available in future releases.

"Note"INFORMATION_SCHEMA is a database of database metadata. It stores MySQL's database basic information. and change at any time. Used as an important information provider when viewing information and system decisions.