DuckDB - Study Notes 7

 

 

import duckdb

duckdb.sql("SELECT 'duck' AS animal, 'quack!' AS greeting")

 

┌─────────┬──────────┐
│ animal  │ greeting │
│ varchar │ varchar  │
├─────────┼──────────┤
│ duck    │ quack!   │
└─────────┴──────────┘

 

 

 

conn = duckdb.connect()
conn.sql(
    """
    CREATE TABLE hello AS
    SELECT 'pato' AS animal, 'cuac!' AS greeting
    """
)
conn.sql("SELECT * FROM hello")

 

┌─────────┬──────────┐
│ animal  │ greeting │
│ varchar │ varchar  │
├─────────┼──────────┤
│ pato    │ cuac!    │
└─────────┴──────────┘

 

another_conn = duckdb.connect(database=":memory:")

 

default_conn = duckdb.connect(database=":default:")

 

custom_conn = duckdb.connect(
    config={
        "memory_limit": "10GB",
        "threads": 4
    }
)

 

conn = duckdb.connect(database="quack.duckdb")
conn.sql(
    """
    CREATE OR REPLACE TABLE hello AS
    SELECT 'ente' AS animal, 'quak!' AS greeting
    """
)
conn.close()

 

 

 

sql = "INSERT INTO hello VALUES ('Fulvigula', 'quack!')"
conn = duckdb.connect(database="quack.duckdb")
conn.sql(sql)
conn.close()

 

sql = "INSERT INTO hello VALUES ('Labradorius', 'quack!')"
with duckdb.connect(database="quack.duckdb") as conn:
    conn.sql(sql)

 

 

conn = duckdb.connect(database="quack.duckdb", read_only=True)
# query the database here...
conn.close()

 

 

duckdb.install_extension("spatial")
duckdb.load_extension("spatial")

 

duckdb.sql(
    """
    SELECT *
    FROM duckdb_extensions()
    WHERE loaded = true
    """
)

 

Let’s run the same query again on a new in-memory database to confirm that the spatial extension was only installed and loaded for the default database:

conn = duckdb.connect()
conn.sql(
    """
    SELECT *
    FROM duckdb_extensions()
    WHERE loaded = true
    """
)

This query shows that the new in-memory database does not have the spatial extension installed or loaded.

To install and load this extension in our new database, we would need to run the following:

conn.install_extension("spatial")
conn.load_extension("spatial")