fixes #16

lodstorage/sql.py

@@ -78,7 +78,7 @@ def execute(self,ddlCmd):
         '''
         self.c.execute(ddlCmd)
 
-    def createTable(self,listOfRecords,entityName,primaryKey=None,withDrop=False,sampleRecordCount=1):
+    def createTable(self,listOfRecords,entityName,primaryKey=None,withDrop=False,sampleRecordCount=1,failIfToFew=True):
         '''
         derive  Data Definition Language CREATE TABLE command from list of Records by examining first recorda
         as defining sample record and execute DDL command
@@ -91,12 +91,18 @@ def createTable(self,listOfRecords,entityName,primaryKey=None,withDrop=False,sam
            primaryKey(string): the key/column to use as a  primary key
            withDrop(boolean): true if the existing Table should be dropped
            sampleRecords(int): number of sampleRecords expected and to be inspected
-           
+           failIftoFew(boolean): raise an Exception if to few sampleRecords else warn only
         Returns:
            EntityInfo: meta data information for the created table
         '''
-        if len(listOfRecords)<sampleRecordCount:
-            raise Exception("Need %d sample records to createTable" % (sampleRecordCount))
+        l= len(listOfRecords)
+        if l<sampleRecordCount:
+            msg="only %d/%d of needed sample records to createTable available" % (l,sampleRecordCount)
+            if failIfToFew:
+                raise Exception(msg)
+            else:
+                if self.debug:
+                    print(msg,file=sys.stderr,flush=True)
         sampleRecords=listOfRecords[:sampleRecordCount]
         entityInfo=EntityInfo(sampleRecords,entityName,primaryKey,debug=self.debug)
         if withDrop:

setup.py

@@ -11,7 +11,7 @@
 
 setup(
     name='pylodstorage',
-    version='0.0.19',
+    version='0.0.20',
 
     packages=['lodstorage',],
     author='Wolfgang Fahl',

tests/testSqlite3.py

@@ -309,6 +309,26 @@ def testCopy(self):
         # https://stackoverflow.com/a/44707371/1497139
         copyDB.execute("pragma user_version=0")
 
+    def testIssue16(self):
+        '''
+        https://github.com/WolfgangFahl/pyLoDStorage/issues/16
+        allow to only warn if samplerecordcount is higher than number of available records
+        '''
+        listOfRecords=Sample.getSample(1000)
+        sqlDB=SQLDB()
+        entityName="sample"
+        primaryKey='pKey'
+        withDrop=False
+        sampleRecordCount=10000
+        sqlDB.debug=True
+        sqlDB.createTable(listOfRecords, entityName, primaryKey, withDrop, sampleRecordCount,failIfToFew=False)
+        withDrop=True
+        try:
+            sqlDB.createTable(listOfRecords, entityName, primaryKey, withDrop, sampleRecordCount)
+            self.fail("There should be an exception that too few sample records where provided")
+        except Exception as ex:
+            self.assertTrue("only 1000/10000 of needed sample records to createTable available" in str(ex))
+
 
 if __name__ == "__main__":
     #import sys;sys.argv = ['', 'Test.testSqllit3']