import basic.program import utils.config_tool import utils.db_abstract import pyspark import basic.constants DATA_NODE_HEADER = basic.constants.DATA_NODE_HEADER DATA_NODE_DATA = basic.constants.DATA_NODE_DATA class DbFcts(utils.db_abstract.DbFcts): """ This interface defines each necessary connection to any kind of database. The specific technique how to connect to the concrete DBMS has to be implemented in the specific tool. """ def __init__(self): pass def selectRows(self, table): """ method to select rows from a database statement written in sql """ tdata={} job = basic.program.Job.getInstance() verify = -1+job.getDebugLevel("db_tool") cmd = "SELECT "+self.comp.conf["ddl"][table]["fields"].join(",")\ +" FROM "+table+""+self.getWhere()+""+self.getOrder()";" spark = self.getConnector() df = spark.sql(cmd) data = [] for r in df: data.append(r) tdata[DATA_NODE_HEADER] = self.comp.conf["ddl"][table]["fields"] tdata[DATA_NODE_DATA] = data return tdata def deleteRows(self, table): """ method to delete rows from a database statement written in sql """ job = basic.program.Job.getInstance() verify = -1+job.getDebugLevel("db_tool") cmd = "DELETE FROM "+table+";" self.comp.m.logInfo(cmd) def updateRows(self, statement): """ method to delete rows from a database statement written in sql """ raise Exception("method is not implemented") def insertRows(self, table, rows): """ method to insert rows into a database the rows will be interpreted by the ddl of the component """ job = basic.program.Job.getInstance() verify = -1+job.getDebugLevel("db_tool") spark = self.getConnector() df = spark.createDataFrame(rows) self.comp.m.logInfo("cmd") def getConnector(self): """ add-on-method to get the connector this method should only called by the class itself """ job = basic.program.Job.getInstance() spark = pyspark.SparkSession.builder()\ .master("local[1]")\ .appName("SparkByExamples.com")\ .getOrCreate() return spark @staticmethod def execStatement(self, comp, conn, statement): """ add-on-method to execute the statement this method should only called by the class itself """ raise Exception("method is not implemented")