Cannot Insert into SQL using PySpark, but works in SQL - sql-server

Question

I have created a table below in SQL using the following:
CREATE TABLE [dbo].[Validation](
[RuleId] [int] IDENTITY(1,1) NOT NULL,
[AppId] [varchar](255) NOT NULL,
[Date] [date] NOT NULL,
[RuleName] [varchar](255) NOT NULL,
[Value] [nvarchar](4000) NOT NULL
)
NOTE the identity key (RuleId)
When inserting values into the table as below in SQL it works:
Note: Not inserting the Primary Key as is will autofill if table is empty and increment
INSERT INTO dbo.Validation VALUES ('TestApp','2020-05-15','MemoryUsageAnomaly','2300MB')
However when creating a temp table on databricks and executing the same query below running this query on PySpark as below:
%python
driver = <Driver>
url = "jdbc:sqlserver:<URL>"
database = "<db>"
table = "dbo.Validation"
user = "<user>"
password = "<pass>"
#import the data
remote_table = spark.read.format("jdbc")\
.option("driver", driver)\
.option("url", url)\
.option("database", database)\
.option("dbtable", table)\
.option("user", user)\
.option("password", password)\
.load()
remote_table.createOrReplaceTempView("YOUR_TEMP_VIEW_NAMES")
sqlcontext.sql("INSERT INTO YOUR_TEMP_VIEW_NAMES VALUES ('TestApp','2020-05-15','MemoryUsageAnomaly','2300MB')")
I get the error below:
AnalysisException: 'unknown requires that the data to be inserted have the same number of columns as the target table: target table has 5 column(s) but the inserted data has 4 column(s), including 0 partition column(s) having constant value(s).;'
Why does it work on SQL but not when passing the query through databricks? How can I insert through pyspark without getting this error?

Answer 1

The most straightforward solution here is use JDBC from a Scala cell. EG
%scala
import java.util.Properties
import java.sql.DriverManager
val jdbcUsername = dbutils.secrets.get(scope = "kv", key = "sqluser")
val jdbcPassword = dbutils.secrets.get(scope = "kv", key = "sqlpassword")
val driverClass = "com.microsoft.sqlserver.jdbc.SQLServerDriver"
// Create the JDBC URL without passing in the user and password parameters.
val jdbcUrl = s"jdbc:sqlserver://xxxx.database.windows.net:1433;database=AdventureWorks;encrypt=true;trustServerCertificate=false;hostNameInCertificate=*.database.windows.net;loginTimeout=30;"
// Create a Properties() object to hold the parameters.
val connectionProperties = new Properties()
connectionProperties.put("user", s"${jdbcUsername}")
connectionProperties.put("password", s"${jdbcPassword}")
connectionProperties.setProperty("Driver", driverClass)
val connection = DriverManager.getConnection(jdbcUrl, jdbcUsername, jdbcPassword)
val stmt = connection.createStatement()
val sql = "INSERT INTO dbo.Validation VALUES ('TestApp','2020-05-15','MemoryUsageAnomaly','2300MB')"
stmt.execute(sql)
connection.close()
You could use pyodbc too, but the SQL Server ODBC drivers aren't installed by default, and the JDBC drivers are.
A Spark solution would be to create a view in SQL Server and insert against that. eg
create view Validation2 as
select AppId,Date,RuleName,Value
from Validation
then
tableName = "Validation2"
df = spark.read.jdbc(url=jdbcUrl, table=tableName, properties=connectionProperties)
df.createOrReplaceTempView(tableName)
sqlContext.sql("INSERT INTO Validation2 VALUES ('TestApp','2020-05-15','MemoryUsageAnomaly','2300MB')")
If you want to encapsulate the Scala and call it from another language (like Python), you can use a scala package cell.
eg
%scala
package example
import java.util.Properties
import java.sql.DriverManager
object JDBCFacade
{
def runStatement(url : String, sql : String, userName : String, password: String): Unit =
{
val connection = DriverManager.getConnection(url, userName, password)
val stmt = connection.createStatement()
try
{
stmt.execute(sql)
}
finally
{
connection.close()
}
}
}
and then you can call it like this:
jdbcUsername = dbutils.secrets.get(scope = "kv", key = "sqluser")
jdbcPassword = dbutils.secrets.get(scope = "kv", key = "sqlpassword")
jdbcUrl = "jdbc:sqlserver://xxxx.database.windows.net:1433;database=AdventureWorks;encrypt=true;trustServerCertificate=false;hostNameInCertificate=*.database.windows.net;loginTimeout=30;"
sql = "select 1 a into #foo from sys.objects"
sc._jvm.example.JDBCFacade.runStatement(jdbcUrl,sql, jdbcUsername, jdbcPassword)