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.
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. |