ArcSDESQLExecute

Summary

The ArcSDESQLExecute class provides a means of executing SQL statements via an ArcSDE connection.

Discussion

CautionCaution:
  • ArcSDE and GDB system tables should not be altered using anything other than ArcGIS software. Corruption can occur if these system tables are edited directly using SQL.
  • Edits on versioned data performed using SQL should only be done through multiversioned views.
  • For geodatabases implemented in a relational database management system (DBMS) using DBMS data types and table formats, the DBMS's own SQL may be used to work with the information stored in the database.
  • Accessing the information in a geodatabase via SQL allows external applications to access the tabular data managed by the geodatabase. These external applications may be nonspatial database applications or custom spatial applications developed in an environment other than ArcObjects. Be aware, though, that SQL access to the geodatabase bypasses geodatabase functionality, such as topology, networks, terrains, or other class or workspace extensions.
  • It may be possible to use DBMS features such as triggers and stored procedures to maintain the relationships between tables needed for certain geodatabase functionality. However, executing SQL commands against the database without taking this extra functionality into account—for example, issuing INSERT statements to add records to a business table—will circumvent geodatabase functionality and possibly corrupt the relationships between data in your geodatabase.
  • Before attempting to access or modify any ArcSDE or GDB objects, read all ArcSDE and geodatabase documentation about using SQL against ArcSDE or GDB objects in the DBMS.

Syntax

ArcSDESQLExecute ({server}, {instance}, {database}, {user}, {password})
ParameterExplanationData Type
server

Name of the server on which the database is installed.

String
instance

The port number

String
database

Name of the database.

String
user

The user name.

String
password

The password for the user name.

String

Properties

PropertyExplanationData Type
transactionAutoCommit
(Read and Write)

The autocommit interval. This can be used to force intermediate commits after a specified number of features have been modified.

Integer

Method Overview

MethodExplanation
commitTransaction ()

No DML statements will be committed until the CommitTransaction method is called.

NoteNote:

A commit may also occur when the connection to ArcSDE it terminated (check specific DBMS documentation to see how each DBMS deals with a disconnect while in a transaction).

execute (sql_statement)

Sends the SQL statement to the database via an ArcSDE connection. If execute is run outside of a transaction, a commit will automatically take place once the SQL DML (INSERT, UPDATE, DELETE . . .) statement has been executed.

rollbackTransaction ()

Rollback any DML operations to the previous commit.

startTransaction ()

To control when your changes are committed to the database, call the startTransaction method before calling execute. This starts a transaction and no DML statements will be committed until the commitTransaction method is called.

Methods

commitTransaction ()
execute (sql_statement)
ParameterExplanationData Type
sql_statement

The SQL statement.

String
rollbackTransaction ()
startTransaction ()

Code Sample

Execute a list of SQL statements
import arcpy
from arcpy import env
import sys

try:
    # Make data path relative
    #
    env.workspace = sys.path[0]
    
    # Two ways to create the object, which also creates the connection to ArcSDE.
    #   Using the first method, pass a set of strings containing the connection properties:
    #   <serverName>,<portNumber>,<version>,<userName>,<password>
    #   sdeConn = arcpy.ArcSDESQLExecute("gpserver3","5151","#","toolbox","toolbox")
    #   Using the second method pass the path to a valid ArcSDE connection file
    #
    sdeConn = arcpy.ArcSDESQLExecute("data\Connection to GPSERVER3.sde")
    
    # Get the SQL statements, separated by ; from a text string.
    #
    SQLStatement = arcpy.GetParameterAsText(0)
    SQLStatementList = SQLStatement.split(";")
    
    print "+++++++++++++++++++++++++++++++++++++++++++++\n"

    # For each SQL statement passed in, execute it.
    #
    for sql in SQLStatementList:
        print "Execute SQL Statement: " + sql
        try:
            # Pass the SQL statement to the database.
            #
            sdeReturn = sdeConn.execute(sql)
        except Exception, ErrorDesc:
            print ErrorDesc
            sdeReturn = False
        
        # If the return value is a list (a list of lists), display each list as a row from the 
        #   table being queried.
        if isinstance(sdeReturn, list):
            print "Number of rows returned by query: " + len(sdeReturn), "rows"
            for row in sdeReturn:
                print row
            print "+++++++++++++++++++++++++++++++++++++++++++++\n"
        else:
            # If the return value was not a list, the statement was most likely a DDL statment. 
            #   Check its status.
            if sdeReturn == True:
                print "SQL statement: " + sql + " ran sucessfully."
                print "+++++++++++++++++++++++++++++++++++++++++++++\n"
            else:
                print "SQL statement: " + sql + " FAILED."
                print "+++++++++++++++++++++++++++++++++++++++++++++\n"
                
except Exception, ErrorDesc:
    print Exception, ErrorDesc
except:
    print "Problem executing SQL."

Conditional update using a transaction
# WARNING - DO NOT USE ON VERSIONED TABLES OR FEATURE CLASSES. 
#   DO NOT USE ON ANY ArcSDE or GDB SYSTEM TABLES.
#   DOING SO MAY RESULT IN DATA CORRUPTION.

import arcpy
from arcpy import env
import sys

try:
    # Make data path relative (not relevant unless data is moved here and paths modified)
    #
    env.workspace = sys.path[0]

    #Column name:value that should be in the record.
    #
    SQLvalues = {"STREET_NAM":"'EUREKA'"}

    #Value that is incorrect if found in the above column.
    #
    badVal = "'EREKA'"

    #List of tables to look in for the bad value.
    #
    tableList = ["streetaddresses_blkA","streetaddresses_blkB", "streetaddresses_blkC"]
    
    # Two ways to create the object, which also creates the connection to ArcSDE.
    #   Using the first method, pass a set of strings containing the connection properties:
    #   <serverName>,<portNumber>,<version>,<userName>,<password>
    #
    sdeConn = arcpy.ArcSDESQLExecute("gpserver3","5151","#","toolbox","toolbox")

    # Using the second method pass the path to a valid ArcSDE connection file
    #   sdeConn = arcpy.ArcSDESQLExecute("data\Connection to GPSERVER3.sde")

    for tbl in tableList:
        print "++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++"
        for col, val in SQLvalues.items():
            print "++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++"
            #Check for the incorrect value in the column for the specific rows. If the table contains the 
            #incorrect value, correct it using the update SQL statement.
            #
            print "Analyzing table " + tbl + " for bad data: Column:" + col + " Value: " + badVal
            try:
                sql = "select OBJECTID," + col + " from " + tbl + " where " + col + " = " + badVal
                print "Attempt to execute SQL Statement: " + sql
                sdeReturn = sdeConn.execute(sql)
            except Exception, ErrorDesc:
                print ErrorDesc
                sdeReturn = False
            if isinstance(sdeReturn, list):
                if len(sdeReturn) > 0:
                    print "Identified " + str(len(sdeReturn)) + " rows with incorrect data. Starting transaction for update."
                    # Start the transaction
                    #
                    sdeConn.startTransaction()
                    print "Transaction started....."
                    # Perform the update
                    #
                    try:
                        sql = "update " + tbl + " set " + col + "=" + str(val) + " where " + col + " = " + badVal
                        print "Changing bad value: " + badVal + " to the good value: " + val + " using update statement:\n " + sql
                        sdeReturn = sdeConn.execute(sql)
                    except Exception, ErrorDesc:
                        print ErrorDesc
                        sdeReturn = False

                    # If the update completed sucessfully, commit the changes.  If not, rollback.
                    #
                    if sdeReturn == True:
                        print "Update statement: \n" + sql + " ran successfully."
                        # Commit the changes
                        #
                        sdeConn.commitTransaction()
                        print "Commited Transaction"

                        # List the changes.
                        #
                        try:
                            print "Displaying updated rows for visual inspection."
                            sql = "select OBJECTID," + col + " from " + tbl + " where " + col + " = " + val
                            print "Executing SQL Statement: \n" + sql
                            sdeReturn = sdeConn.execute(sql)
                        except Exception, ErrorDesc:
                            print ErrorDesc
                            sdeReturn = False
                        if isinstance(sdeReturn, list):
                            print len(sdeReturn), "rows"
                            for row in sdeReturn:
                                print row
                            print "+++++++++++++++++++++++++++++++++++++++++++++\n"
                        else:
                            if sdeReturn == True:
                                print "SQL statement: \n" + sql + "\nran successfully."
                                print "+++++++++++++++++++++++++++++++++++++++++++++\n"
                            else:
                                print "SQL statement: \n" + sql + "\nFAILED."
                                print "+++++++++++++++++++++++++++++++++++++++++++++\n"

                        print "+++++++++++++++++++++++++++++++++++++++++++++\n"
                    else:
                        print "SQL statement: \n" + sql + "\nFAILED.  Rolling back all changes."
                        # Rollback changes
                        #
                        sdeConn.rollbackTransaction()
                        print "Rolled back any changes."
                        print "+++++++++++++++++++++++++++++++++++++++++++++\n"
            else:
                print "No records required updating."
            
    # Disconnect and exit
    del sdeConn
    print "++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++"

except Exception, ErrorDesc:
    print Exception, ErrorDesc
except:
    print "Problem executing SQL."

Related Topics


10/28/2011