mssql.md

MsSQL

SQLServer does not need to specify protocol.

MsSQL Connection

if the user password has special characters, they need to be sanitized. example: `from urllib import parse; password = parse.quote_plus(password)`

import connectorx as cx
conn = 'mssql://username:password@server:port/database?encrypt=true&trusted_connection=true'         # connection token
query = 'SELECT * FROM table'                                   # query string
cx.read_sql(conn, query)                                        # read data from MsSQL

Connection Parameters

• By adding trusted_connection=true to connection uri parameter, windows authentication will be enabled.
  • Example: mssql://host:port/db?trusted_connection=true
• By adding encrypt=true to connection uri parameter, SQLServer will use SSL encryption.
  • Example: mssql://host:port/db?encrypt=true&trusted_connection=true
• By adding trust_server_certificate=true to connection uri parameter, the SQLServer certificate will not be validated and it is accepted as-is.
  • Example: mssql://host:port/db?trust_server_certificate=true&encrypt=true
• By adding trust_server_certificate_ca=/path/to/ca-cert.crt to connection uri parameter, the SQLServer certificate will be validated against the given CA certificate in addition to the system-truststore.
  • Example: mssql://host:port/db?encrypt=true&trust_server_certificate_ca=/path/to/ca-cert.crt

SQLServer-Pandas Type Mapping

SQLServer Type	Pandas Type	Comment
TINYINT	int64, Int64(nullable)
SMALLINT	int64, Int64(nullable)
INT	int64, Int64(nullable)
BIGINT	int64, Int64(nullable)
FLOAT	float64
NUMERIC	float64
DECIMAL	float64	cannot support precision larger than 28
BIT	bool, boolean(nullable)
VARCHAR	object
CHAR	object
TEXT	object
NVARCHAR	object
NCHAR	object
NTEXT	object
VARBINARY	object
BINARY	object
IMAGE	object
DATETIME	datetime64[ns]
DATETIME2	datetime64[ns]
SMALLDATETIME	datetime64[ns]
DATE	datetime64[ns]
DATETIMEOFFSET	datetime64[ns]
TIME	object
UNIQUEIDENTIFIER	object

Performance (r5.4xlarge docker in another EC2 instance)

Modin does not support read_sql on Mssql

• Time chart, lower is better.

• Memory consumption chart, lower is better.

In conclusion, ConnectorX uses 3x less memory and 14x less time compared with Pandas.