Connect with SQLAlchemy
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You can connect to your SingleStore deployments from SQLAlchemy using the SingleStore SQLAlchemy dialect (singlestoredb://
).
Remarks
-
Use the SingleStore dialect (
singlestoredb://
) in thecreate_
statement.engine() -
Use one of the supported Python libraries.
SingleStore recommends using the SingleStore Python Client. -
Use
127.
instead of0. 0. 1 localhost
in thecreate_
statement.engine()
Example
The following example connects to a SingleStore deployment using SQLAlchemy and returns all the rows in a table named strg.
This example uses the following connection parameters:
-
Dialect:
singlestoredb://
-
SingleStore database username:
s2user
-
Password of the SingleStore database user:
passkey
-
Hostname of the SingleStore deployment:
svchost
-
Port:
3306
-
Database name:
dbTest
-
Run the following command in the SingleStore command line:
CREATE TABLE strg (ID INT, Name VARCHAR(20));INSERT INTO strg VALUES (1, "sam_duke");INSERT INTO strg VALUES (2, "adam_west");INSERT INTO strg VALUES (3, "anna_moore");SELECT * FROM strg;+----+------------+ | ID | Name | +----+------------+ | 1 | sam_duke | | 2 | adam_west | | 3 | anna_moore | +----+------------+
-
Create a
.
file (say pyTest.py py), and add the following code to the file: from sqlalchemy import create_engine, textengine = create_engine('singlestoredb://s2user:passkey@svchost/dbTest')conn = engine.connect()result = conn.execute(text("SELECT * FROM strg"))for row in result:print(row) -
Run the following command:
python3 pyTest.py(3, 'anna_moore') (2, 'adam_west') (1, 'sam_duke')
The following examples perform CRUD operations using the same connection parameters.
Create Operation Example
Add the following code to a .
file (say ct.
from sqlalchemy import create_engine, textengine = create_engine('singlestoredb://s2user:passkey@svchost:3306/dbTest')conn = engine.connect()conn.execute(text("CREATE TABLE stock (ID INT, Code VARCHAR(4), Qty INT)"))conn.execute(text("INSERT INTO stock VALUES (1,'xvfg',23)"))conn.execute(text("INSERT INTO stock VALUES (2,'dtsi',12)"))conn.execute(text("INSERT INTO stock VALUES (3,'rtky',8)"))conn.close()
Run the following command:
python3 ct.py
Read Operation Example
Add the following code to a .
file (say rt.
from sqlalchemy import create_engine, textengine = create_engine('singlestoredb://s2user:passkey@svchost:3306/dbTest')conn = engine.connect()result = conn.execute(text("SELECT * FROM stock"))for row in result:print(row)conn.close()
Run the following command:
python3 rt.py
(1, 'xvfg', 23)
(2, 'dtsi', 12)
(3, 'rtky', 8)
Update Operation Example
Add the following code to a .
file (say ut.
from sqlalchemy import create_engine, textengine = create_engine('singlestoredb://s2user:passkey@svchost:3306/dbTest')conn = engine.connect()conn.execute(text("UPDATE stock SET Qty = 10 WHERE Code = 'rtky'"))result = conn.execute(text("SELECT * FROM stock"))for row in result:print(row)conn.close()
Run the following command:
python3 ut.py
(3, 'rtky', 10)
(1, 'xvfg', 23)
(2, 'dtsi', 12)
Delete Operation Example
Add the following code to a .
file (say dt.
from sqlalchemy import create_engine, textengine = create_engine('singlestoredb://s2user:passkey@svchost:3306/dbTest')conn = engine.connect()conn.execute(text("DELETE FROM stock WHERE code = 'rtky'"))result = conn.execute(text("SELECT * FROM stock"))for row in result:print(row)conn.close()
Run the following command:
python3 dt.py
(1, 'xvfg', 23)
(2, 'dtsi', 12)
Refer to SQLAlchemy SQL Expression Language Tutorial for more examples.
Troubleshooting
Error: ModuleNotFoundError: No module named 'MySQLdb'
Solution: Install a supported Python library, for example the SingleStore Python Client.
Error: Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld. sock'
Solution: To resolve this issue:
-
Specify
127.
as the host instead of0. 0. 1 localhost
. -
Modify the
socket
value in the/etc/mysql/my.
file to your SingleStore socket.cnf For example, [client] port = 3306 socket = /var/lib/memsql/<Singlestore_node_id>/data/memsql.sock
Replace
<Singlestore_
with the MemSQL ID of the aggregator node.node_ id> Run the sdb-admin list-nodes
command to list the SingleStore nodes.
References
Last modified: March 26, 2025