Updated on 2022-08-16 GMT+08:00

DBA_TAB_COLUMNS

DBA_TAB_COLUMNS displays the columns of tables. Each column of a table in the database has a row in DBA_TAB_COLUMNS. It is accessible only to users with system administrator rights.

Table 1 DBA_TAB_COLUMNS columns

Name

Type

Description

owner

character varying(64)

Table owner

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

Sequence number of the column when the table is created

data_length

integer

Length of the column in the unit of bytes

comments

text

Comments

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, however its value is 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) which is valid only for varchar, nvarchar2, bpchar, and char types.