columns

The columns view provides information about columns in tables. The related st_geometry_columns table provides information about table columns that store spatial data. For details, see Table 1. This view is read-only. All users have the read permission on this view.

**Table 1** information_schema.columns columns
Name	Type	Description
TABLE_CATALOG	varchar(512)	Name of the catalog (database) to which the table containing the column belongs. The value is the name of the current database. When lower_case_table_names is set to 0, the value of this column is case-sensitive. When lower_case_table_names is set to 1, the value of this column is case-insensitive.
TABLE_SCHEMA	varchar(64)	Name of the schema to which the table containing the column belongs. When lower_case_table_names is set to 0, the value of this column is case-sensitive. When lower_case_table_names is set to 1, the value of this column is case-insensitive.
TABLE_NAME	varchar(64)	Name of the table containing the column. When lower_case_table_names is set to 0, the value of this column is case-sensitive. When lower_case_table_names is set to 1, the value of this column is case-insensitive.
COLUMN_NAME	varchar(64)	Name of the column.
ORDINAL_POSITION	bigint unsigned	Position of the column within the table.
COLUMN_DEFAULT	longtext	Default value of the column.
IS_NULLABLE	varchar(3)	Nullability of the column.
DATA_TYPE	varchar(64)	Data type of the column.
CHARACTER_MAXIMUM_LENGTH	bigint unsigned	Maximum length of string columns, in characters.
CHARACTER_OCTET_LENGTH	bigint unsigned	Maximum length of string columns, in bytes.
NUMERIC_PRECISION	bigint unsigned	Precision of numeric columns.
NUMERIC_SCALE	bigint unsigned	Scale of numeric columns.
DATETIME_PRECISION	bigint unsigned	Precision of fractional seconds in temporal columns.
CHARACTER_SET_NAME	varchar(32)	Character set name for string columns.
COLLATION_NAME	varchar(32)	Collation rule name for string columns.
COLUMN_TYPE	longtext	Data type of the column. The value of column_type contains the type name and possibly other information, such as the precision or length.
COLUMN_KEY	varchar(3)	Specifies whether the column is indexed. pri: The column is a primary key or is one of the columns in a multiple-column primary key. uni: The column is the first column of a unique index. mul: The column is the first column of a non-unique index. Empty: The column is not indexed or is not pri, uni, or mul.
EXTRA	varchar(30)	Any other available information about the specified column. The value is not NULL in the following cases: auto_increment: columns with the AUTO_INCREMENT attribute. on update CURRENT_TIMESTAMP: columns with the on update CURRENT_TIMESTAMP attribute for time columns. STORED GENERATED: columns with the STORED GENERATED attribute for generated columns. VIRTUAL GENERATED: columns with the VIRTUAL GENERATED attribute for generated columns.
PRIVILEGES	varchar(80)	Permission the current user has on the column.
COLUMN_COMMENT	varchar(1024)	Any comment included in the column definition.
GENERATION_EXPRESSION	longtext	For a generated column, this column displays the expression used to compute the column value. For a non-generated column, this column is empty.