Re: Insert into table with one the value is derived from DB function using spark

[Mich Talebzadeh]

I gather you mean using JDBC to write to the Oracle table?

Spark provides a unified framework to write to any JDBC compliant database.

def writeTableWithJDBC(dataFrame, url, tableName, user, password, driver,
mode):
    try:
        dataFrame. \
            write. \
            format("jdbc"). \
            option("url", url). \
            option("dbtable", tableName). \
            option("user", user). \
            option("password", password). \
            option("driver", driver). \
            mode(mode). \
            save()
    except Exception as e:
        print(f"""{e}, quitting""")
        sys.exit(1)

and how to write it

 def loadIntoOracleTable(self, df2):
        # write to Oracle table, all uppercase not mixed case and column
names <= 30 characters in version 12.1
        tableName =
self.config['OracleVariables']['yearlyAveragePricesAllTable']
        fullyQualifiedTableName =
self.config['OracleVariables']['dbschema']+'.'+tableName
        user = self.config['OracleVariables']['oracle_user']
        password = self.config['OracleVariables']['oracle_password']
        driver = self.config['OracleVariables']['oracle_driver']
        mode = self.config['OracleVariables']['mode']

s.writeTableWithJDBC(df2,oracle_url,fullyQualifiedTableName,user,password,driver,mode)
        print(f"""created
{config['OracleVariables']['yearlyAveragePricesAllTable']}""")
        # read data to ensure all loaded OK
        fetchsize = self.config['OracleVariables']['fetchsize']
        read_df =
s.loadTableFromJDBC(self.spark,oracle_url,fullyQualifiedTableName,user,password,driver,fetchsize)
        # check that all rows are there
        if df2.subtract(read_df).count() == 0:
            print("Data has been loaded OK to Oracle table")
        else:
            print("Data could not be loaded to Oracle table, quitting")
            sys.exit(1)

in the statement where it says

             option("dbtable", tableName). \

You can replace *tableName* with the equivalent SQL insert statement

You will need JDBC driver for Oracle say ojdbc6.jar in
$SPARK_HOME/conf/spark-defaults.conf

spark.driver.extraClassPath
 /home/hduser/jars/jconn4.jar:/home/hduser/jars/ojdbc6.jar

HTH



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On Fri, 18 Jun 2021 at 20:49, Anshul Kala <anshul.k...@gmail.com> wrote:

> Hi All,
>
> I am using spark to ingest data from file to database Oracle table . For
> one of the fields , the value to be populated is generated from a function
> that is written in database .
>
> The input to the function is one of the fields of data frame
>
> I wanted to use spark.dbc.write to perform the operation, which generates
> the insert query at back end .
>
> For example : It can generate the insert query as :
>
> Insert into table values (?,?, getfunctionvalue(?) )
>
> Please advise if it is possible in spark and if yes , how can it be done
>
> This is little urgent for me . So any help is appreciated
>
> Thanks
> Anshul
>