_mssql
examples
Example scripts using _mssql
module.
Quickstart usage of various features
from pymssql import _mssql
conn = _mssql.connect(server='SQL01', user='user', password='password', \
database='mydatabase')
conn.execute_non_query('CREATE TABLE persons(id INT, name VARCHAR(100))')
conn.execute_non_query("INSERT INTO persons VALUES(1, 'John Doe')")
conn.execute_non_query("INSERT INTO persons VALUES(2, 'Jane Doe')")
# how to fetch rows from a table
conn.execute_query('SELECT * FROM persons WHERE salesrep=%s', 'John Doe')
for row in conn:
print "ID=%d, Name=%s" % (row['id'], row['name'])
Added in version 2.1.0: Iterating over query results by iterating over the connection object
just like it’s already possible with pymssql
connections is new in 2.1.0.
# examples of other query functions
numemployees = conn.execute_scalar("SELECT COUNT(*) FROM employees")
numemployees = conn.execute_scalar("SELECT COUNT(*) FROM employees WHERE name LIKE 'J%'") # note that '%' is not a special character here
employeedata = conn.execute_row("SELECT * FROM employees WHERE id=%d", 13)
# how to fetch rows from a stored procedure
conn.execute_query('sp_spaceused') # sp_spaceused without arguments returns 2 result sets
res1 = [ row for row in conn ] # 1st result
res2 = [ row for row in conn ] # 2nd result
# how to get an output parameter from a stored procedure
sqlcmd = """
DECLARE @res INT
EXEC usp_mystoredproc @res OUT
SELECT @res
"""
res = conn.execute_scalar(sqlcmd)
# how to get more output parameters from a stored procedure
sqlcmd = """
DECLARE @res1 INT, @res2 TEXT, @res3 DATETIME
EXEC usp_getEmpData %d, %s, @res1 OUT, @res2 OUT, @res3 OUT
SELECT @res1, @res2, @res3
"""
res = conn.execute_row(sqlcmd, (13, 'John Doe'))
# examples of queries with parameters
conn.execute_query('SELECT * FROM empl WHERE id=%d', 13)
conn.execute_query('SELECT * FROM empl WHERE name=%s', 'John Doe')
conn.execute_query('SELECT * FROM empl WHERE id IN %s', ((5, 6),))
conn.execute_query('SELECT * FROM empl WHERE name LIKE %s', 'J%')
conn.execute_query('SELECT * FROM empl WHERE name=%(name)s AND city=%(city)s', \
{ 'name': 'John Doe', 'city': 'Nowhere' } )
conn.execute_query('SELECT * FROM cust WHERE salesrep=%s AND id IN %s', \
('John Doe', (1, 2, 3)))
conn.execute_query('SELECT * FROM empl WHERE id IN %s', (tuple(xrange(4)),))
conn.execute_query('SELECT * FROM empl WHERE id IN %s', \
(tuple([3, 5, 7, 11]),))
conn.close()
Please note the usage of iterators and ability to access results by column
name. Also please note that parameters to connect method have different names
than in pymssql
module.
An example of exception handling
from pymssql import _mssql
conn = _mssql.connect(server='SQL01', user='user', password='password',
database='mydatabase')
try:
conn.execute_non_query('CREATE TABLE t1(id INT, name VARCHAR(50))')
except _mssql.MssqlDatabaseException as e:
if e.number == 2714 and e.severity == 16:
# table already existed, so quieten the error
else:
raise # re-raise real error
finally:
conn.close()
Custom message handlers
Added in version 2.1.1.
You can provide your own message handler callback function that will be invoked
by the stack with informative messages sent by the server. Set it on a per
_mssql
connection
basis by using the
_mssql.MSSQLConnection.set_msghandler()
method:
from pymssql import _mssql
def my_msg_handler(msgstate, severity, srvname, procname, line, msgtext):
"""
Our custom handler -- It simply prints a string to stdout assembled from
the pieces of information sent by the server.
"""
print("my_msg_handler: msgstate = %d, severity = %d, procname = '%s', "
"line = %d, msgtext = '%s'" % (msgstate, severity, procname,
line, msgtext))
cnx = _mssql.connect(server='SQL01', user='user', password='password')
try:
cnx.set_msghandler(my_msg_handler) # Install our custom handler
cnx.execute_non_query("USE mydatabase") # It gets called at this point
finally:
cnx.close()
Something similar to this would be printed to the standard output:
my_msg_handler: msgstate = x, severity = y, procname = '', line = 1, msgtext = 'Changed database context to 'mydatabase'.'
Todo
Add an example of invoking a Stored Procedure using _mssql
.