ALL_TAB_COLUMNS

ALL_TAB_COLUMNS displays description information about columns of the tables accessible to the current user.

Table 1 ALL_TAB_COLUMNS columns

Name

Type

Description

owner

character varying(64)

Owner of the table

table_name

character varying(64)

Table name

column_name

character varying(64)

Column name

data_type

character varying(128)

Data type of the column

column_id

integer

Column ID generated when the object is created or column is added

data_length

integer

Length of the column in the unit of bytes

avg_col_len

numeric

Average length of a column in the unit of bytes

nullable

bpchar

Whether the column can be empty. For the primary key constraint and non-null constraint, the value is n.

data_precision

integer

Indicates the precision of the data type. This parameter is valid for the numeric data type and NULL for other types.

data_scale

integer

Number of decimal places. This parameter is valid for the numeric data type. For other data types, the value of this parameter is 0.

char_length

numeric

Column length in the unit of bytes. This parameter is valid only for the varchar, nvarchar2, bpchar, and char types.