SQL Statements
DESCRIBE statement
Overview
Describe
statement show columns within a table and tables within a database.
The
Describe
statement is recommended to use before creating a new table to avoid duplicate tables.Syntax
Describe Database
Below is the basic syntax for describing tables within a database:
DESCRIBE DATABASE;
Describe Table
Below is the basic syntax for describing columns within a table:
DESCRIBE TABLE table_name;
table_name
is the name of the table that you want to show.
Examples
To get a better understanding of a DESCRIBE
statement, take a look at some examples below:
Case #1: Describe Table
- In this example, we will figure out the columns of a part table. Run the query below:
DESCRIBE TABLE part;
- As a result, you will get a list of column names, column types, and nullable options from the part table.
+----------------+------------+-------------+-------+----------+
| database_name | table_name | name | type | nullable |
+----------------+------------+-------------+-------+----------+
| public | part | p_partkey | INT | f |
| public | part | p_name | TEXT | f |
| public | part | p_mfgr | TEXT | f |
| public | part | p_category | TEXT | f |
| public | part | p_brand | TEXT | f |
| public | part | p_color | TEXT | f |
| public | part | p_type | TEXT | f |
| public | part | p_size | INT | f |
| public | part | p_container | TEXT | f |
+----------------+------------+-------------+-------+----------+
The example above shows that the tables reside in the
public
schema, the default schema in Oxla. You can also have a table from other schemas - click here for more info.Case #2: Describe Database
- Execute the following query to describe the database:
DESCRIBE DATABASE;
- You will retrieve a list of the existing tables in the database as shown below:
+-----------------------------+
| name |
+-----------------------------+
| supplier_scale_1_no_index |
| features |
| orders |
| features2 |
| featurestable |
| featurestable1 |
| featurestable10 |
+-----------------------------+