Query column information in mysql

Each column that the current user can access in the current database occupies one row in this view. The INFORMATION_SCHEMA.COLUMNS view is based on sysobjects, spt_datatype_info, systypes, syscolumns, syscomments, sysconfigures, and syscharsets.

Each column that the current user can access in the current database occupies one row in this view. The INFORMATION_SCHEMA.COLUMNS view is based on sysobjects, spt_data type_info, policypes, syscolumns, syscomments, sysconfigures, and syscharsets.

Each column that the current user can access in the current database occupies one row in this view. The INFORMATION_SCHEMA.COLUMNS view is based on sysobjects, spt_data type_info, policypes, syscolumns, syscomments, sysconfigures, and syscharsets system tables.

To retrieve information from these views, specify the fully qualified INFORMATION_SCHEMA view_name name.

Column name	Data Type	Description
TABLE_CATALOG	Nvarchar (128)	Table qualifier.
TABLE_SCHEMA	Nvarchar (128)	Table owner.
TABLE_NAME	Nvarchar (128)	Table name.
COLUMN_NAME	Nvarchar (128)	Column name.
ORDINAL_POSITION	Smallint	Column ID.
COLUMN_DEFAULT	Nvarchar (4000)	Column default value.
IS_NULLABLE	Varchar (3)	Column is null. If the column allows NULL, YES is returned for this column. Otherwise, NO is returned.
DATA_TYPE	Nvarchar (128)	The data type provided by the system.
CHARACTER_MAXIMUM_LENGTH	Smallint	The maximum length in characters. It is suitable for binary data, character data, or text and image data. Otherwise, NULL is returned. For more information, see data types.
CHARACTER_OCTET_LENGTH	Smallint	The maximum length in bytes. It is suitable for binary data, character data, or text and image data. Otherwise, NULL is returned.
NUMERIC_PRECISION	Tinyint	Precision of approximate numeric data, precise numeric data, integer data, or currency data. Otherwise, NULL is returned.
NUMERIC_PRECISION_RADIX	Smallint	The precision base of approximate numeric data, precise numeric data, integer data, or currency data. Otherwise, NULL is returned.
NUMERIC_SCALE	Tinyint	Number of decimal places in approximate numeric data, precise numeric data, integer data, or currency data. Otherwise, NULL is returned.
DATETIME_PRECISION	Smallint	Child type code for datetime and SQL-92interval data types. For other data types, return NULL.
CHARACTER_SET_CATALOG	Varchar (6)	If the column is of the character data or text data type, the master is returned, indicating the database where the character set is located. Otherwise, NULL is returned.
CHARACTER_SET_SCHEMA	Varchar (3)	If the column is of the character data or text data type, DBO is returned, indicating the name of the character set owner. Otherwise, NULL is returned.
CHARACTER_SET_NAME	Nvarchar (128)	If the column is of the character or text data type, a unique name is returned for the character set. Otherwise, NULL is returned.
COLLATION_CATALOG	Varchar (6)	If the column is of the character or text data type, the master is returned, indicating the database in which the sorting order is defined. Otherwise, this column is NULL.
COLLATION_SCHEMA	Varchar (3)	Return DBO, indicating the owner of the sort order for the character data or text data type. Otherwise, NULL is returned.
COLLATION_NAME	Nvarchar (128)	If the column is of the character or text data type, a unique name is returned for the sorting order. Otherwise, NULL is returned.
DOMAIN_CATALOG	Nvarchar (128)	If a column is a user-defined data type, the column is a database name, and this user-defined data type is created in the database name. Otherwise, NULL is returned.
DOMAIN_SCHEMA	Nvarchar (128)	If a column is a user-defined data type, the column is the creator of the User-Defined data type. Otherwise, NULL is returned.
DOMAIN_NAME	Nvarchar (128)	If a column is a user-defined data type, this column is the name of the user-defined data type. Otherwise, NULL is returned.