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• STORED GENERATED  or VIRTUAL GENERATED  for generated columns. 

• DEFAULT_GENERATED  for columns that have an expression default value. 

• PRIVILEGES 

The privileges you have for the column. 

• COLUMN_COMMENT 

Any comment included in the column definition. 

• GENERATION_EXPRESSION 

For generated columns, displays the expression used to compute column values. Empty for nongenerated columns. For information about generated columns, see Section 13.1.20.8, “CREATE TABLE and Generated Columns” . 

• SRS_ID 

This value applies to spatial columns. It contains the column SRID  value that indicates the spatial reference system for values stored in the column. See Section 11.4.1, “Spatial Data Types” , and Section 11.4.5, “Spatial Reference System Support” . The value is NULL  for nonspatial columns and spatial columns with no SRID  attribute. 

## Notes 

•In SHOW COLUMNS , the Type  display includes values from several different COLUMNS  columns. 

• CHARACTER_OCTET_LENGTH  should be the same as CHARACTER_MAXIMUM_LENGTH , except for multibyte character sets. 

• CHARACTER_SET_NAME  can be derived from COLLATION_NAME . For example, if you say SHOW FULL COLUMNS FROM t , and you see in the COLLATION_NAME  column a value of utf8_swedish_ci , the character set is what is before the first underscore: utf8 . 

Column information is also available from the SHOW COLUMNS  statement. See Section 13.7.7.5, “SHOW COLUMNS Statement” . The following statements are nearly equivalent: 

SELECT COLUMN_NAME, DATA_TYPE, IS_NULLABLE, COLUMN_DEFAULT FROM INFORMATION_SCHEMA.COLUMNS WHERE table_name = ’ tbl_name ’ [AND table_schema = ’ db_name ’] [AND column_name LIKE ’ wild ’] 

SHOW COLUMNS FROM tbl_name [FROM db_name ] [LIKE ’ wild ’] 

## 26.3.9 The INFORMATION_SCHEMA COLUMNS_EXTENSIONS Table 

The COLUMNS_EXTENSIONS  table (available as of MySQL 8.0.21) provides information about column attributes defined for primary and secondary storage engines. 

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<img src='content_image/686806.jpg'>

## Note 

The COLUMNS_EXTENSIONS  table is reserved for future use. 

