USER_TAB_COLUMNS

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

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 and 0 for other types.

char_length

numeric

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